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In this study, peptides designed using fragments of an antifreeze protein (AFP) from the freeze-tolerant insect Tenebrio molitor, TmAFP, were evaluated as inhibitors of clathrate hydrate formation. It was found that these peptides exhibit inhibitory effects by both direct and indirect mechanisms. The direct mechanism involves the displacement of methane molecules by hydrophobic methyl groups from threonine residues, preventing their diffusion to the hydrate surface. The indirect mechanism is characterized by the formation of cylindrical gas bubbles, the morphology of which reduces the pressure difference at the bubble interface, thereby slowing methane transport. The transfer of methane to the hydrate interface is primarily dominated by gas bubbles in the presence of antifreeze peptides. Spherical bubbles facilitate methane migration and potentially accelerate hydrate formation; conversely, the promotion of a cylindrical bubble morphology by two of the designed systems was found to mitigate this effect, leading to slower methane transport and reduced hydrate growth. These findings provide valuable guidance for the design of effective peptide-based inhibitors of natural-gas hydrate formation with potential applications in the energy and environmental sectors. [ABSTRACT FROM AUTHOR]

In recent decades, the invasive seaweed Rugulopteryx okamurae has had a huge environmental impact on marine biodiversity, fisheries, GHG emissions and public health along much of the Iberian Peninsula and islands coastline. Due to the enormous amount of algae biomass that is expelled to the beaches where it slowly rots, some circular economy business initiatives, such as composting, are emerging. In the present study, we compared the quality of compost obtained from earthworms (Dendrobaena veneta), cockroaches (Eublaberus sp.), mealworms (Tenebrio molitor) and black soldier fly larvae (Hermetia illucens). Batches fed with 100% organic kitchen waste (control group) were compared with batches fed with 50% algae and 50% kitchen waste (treatment group). Our results show that the most sensitive species (D. veneta and T. molitor) to R. okamurae toxins compost adequately. The C/N ratio, electrical conductivity (EC), pH, total organic matter (TOM), C, K, K2O, Mg, MgO, N, P, P2O5, B, Cu, Ni and Zn of the compost obtained were determined. A high quality compost was obtained in which only the EC values are slightly elevated. Particularly good was the compost obtained with H. illucens and Eublaberus sp. This quality is in agreement with previous research on the mass balance of composting. Therefore, both species offer, in the field of circular economy, encouraging prospects for the development of composting enterprises. [ABSTRACT FROM AUTHOR]

ABSTRACT Arthropods have integrated digestive and renal systems, which function to acquire and maintain homeostatically the substances they require for survival. The cryptonephridial complex (CNC) is an evolutionary novelty in which the renal organs and gut have been dramatically reorganised. Parts of the renal or Malpighian tubules (MpTs) form a close association with the surface of the rectum, and are surrounded by a novel tissue, the perinephric membrane, which acts to insulate the system from the haemolymph and thus allows tight regulation of ions and water into and out of the CNC. The CNC can reclaim water and solutes from the rectal contents and recycle these back into the haemolymph. Fluid flow in the MpTs runs counter to flow within the rectum. It is this countercurrent arrangement that underpins its powerful recycling capabilities, and represents one of the most efficient water conservation mechanisms in nature. CNCs appear to have evolved multiple times, and are present in some of the largest and most evolutionarily successful insect groups including the larvae of most Lepidoptera and in a major beetle lineage (Cucujiformia + Bostrichoidea), suggesting that the CNC is an important adaptation. Here we review the knowledge of this remarkable organ system gained over the past 200 years. We first focus on the CNCs of tenebrionid beetles, for which we have an in‐depth understanding from physiological, structural and ultrastructural studies (primarily in Tenebrio molitor), which are now being extended by studies in Tribolium castaneum enabled by advances in molecular and microscopy approaches established for this species. These recent studies are beginning to illuminate CNC development, physiology and endocrine control. We then take a broader view of arthropod CNCs, phylogenetically mapping their reported occurrence to assess their distribution and likely evolutionary origins. We explore CNCs from an ecological viewpoint, put forward evidence that CNCs may primarily be adaptations for facing the challenges of larval life, and argue that their loss in many aquatic species could point to a primary function in conserving water in terrestrial species. Finally, by considering the functions of renal and digestive epithelia in insects lacking CNCs, as well as the typical architecture of these organs in relation to one another, we propose that ancestral features of these organs predispose them for the evolution of CNCs. [ABSTRACT FROM AUTHOR]

BACKGROUND RESULTS CONCLUSIONS Yellow mealworm (Tenebrio molitor) larvae are increasingly recognized as a potential source of bioactive peptides due to their high protein content. Antimicrobial peptides from sustainable sources are a research topic of interest. This study aims to characterize the peptidome of T. molitor flour and an Alcalase‐derived hydrolysate, and to explore the potential presence of antimicrobial peptides using in silico analyses, including prediction tools, molecular docking and parameter correlations.T. molitor protein was hydrolysed using Alcalase, resulting in a hydrolysate (TMH10A) with a 10% degree of hydrolysis. The peptidome was analysed using LC‐TIMS‐MS/MS, yielding over 6000 sequences. These sequences were filtered using the PeptideRanker tool, selecting the top 100 sequences with scores >0.8. Bioactivity predictions indicated that specific peptides, particularly WLNSKGGF and GFIPYEPFLKKMMA, showed significant antimicrobial potential, particularly against bacteria, fungi and viruses. Correlations were found between antifungal activity and physicochemical properties such as net charge, hydrophobicity and isoelectric point.The study identified specific T. molitor‐derived peptides with strong predicted antimicrobial activity through in silico analysis. These peptides, particularly WLNSKGGF and GFIPYEPFLKKMMA, might offer potential applications in food safety and healthcare. Further experimental validation is required to confirm their efficacy. © 2024 The Author(s). Journal of the Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Solanine (SOL), chaconine (CHA), and tomatine (TOM) are plant secondary metabolites produced mainly by the species of Solanaceae family, such as tomato Solanum lycopersicum L. These glycoalkaloids (GAs) have a wide range of biological activity, also in insects. However, their mechanisms of action are not precisely understood. The purpose of the study was to investigate how pure GAs and tomato leaf extract (EXT) affect glycolysis, Krebs cycle and β-oxidation of fatty acid pathways in Tenebrio molitor L. beetle. For this purpose, the larvae were injected with SOL, CHA, TOM, and EXT at two concentrations (10–8 and 10–5 M). For experiments, fat body, gut, and heamolymph samples were collected 2 and 24 h after injection. Then, the changes in the expression level of phosphofructokinase, citrate synthase, and β-hydroxyacyl-CoA dehydrogenase were measured using the RT-qPCR technique. The catalytic activity of these enzymes and the carbohydrate level in insects after GA treatment were determined by spectrophotometric method. Furthermore, the analysis of the amount of amino acids in tissues was performed with a GC–MS technique. The results obtained show that the GAs changed the activity and expression of the genes encoding key enzymes of crucial metabolic pathways. The effect depends on the type of GA compound, the tissue tested, and the incubation time after treatment. Furthermore, TOM and EXT affected trehalose concentration in the insect hemolymph and led to accumulation of amino acids in the fat body. The observed changes may indicate a protein degradation and/or enhanced catabolism reactions for the production of ATP used in detoxification processes. These results suggest that GAs alter energy metabolism in the mealworm T. molitor. The study contributes to our understanding of the mechanisms of action of secondary metabolites of plants in insects. This knowledge may allow the design of new natural biopesticides against insect pests because proper energy metabolism is necessary for the survival of the organism. [ABSTRACT FROM AUTHOR]

Background: Auranofin is an approved anti-rheumatic drug that has a broad-range inhibitory action against several microorganisms, including human pathogenic fungi. The auranofin activity against Histoplasma capsulatum, the dimorphic fungus that causes histoplasmosis, has not been properly addressed. Since there are few therapeutic options for this life-threatening systemic mycosis, this study evaluated the effects of auranofin on H. capsulatum growth and expression of virulence factors. Methodology/principal findings: Minimal inhibitory and fungicidal concentrations (MIC and MFC, respectively) of auranofin against 15 H. capsulatum strains with distinct genetic backgrounds were determined using the yeast form of the fungus and a microdilution protocol. Auranofin activity was also assessed on a macrophage model of infection and on a Tenebrio molitor invertebrate animal model. Expression of virulence-related genes was compared between auranofin treated and untreated H. capsulatum yeast cells using a quantitative PCR assay. Auranofin affected the growth of different strains of H. capsulatum, with MIC and MFC values ranging from 1.25 to 5.0 μM and from 2.5 to >10 μM, respectively. Auranofin was able to kill intracellular H. capsulatum yeast cells and conferred protection against the fungus in the experimental animal model of infection. Moreover, the expression of catalase A, HSP70, superoxide dismutase, thioredoxin reductase, serine proteinase, cytochrome C peroxidase, histone 2B, formamidase, metallopeptidase, Y20 and YPS3 proteins were reduced after six hours of auranofin treatment. CONCLUSIONS/SIGNIFICANCE: Auranofin is fungicidal against H. capsulatum and reduces the expression of several virulence-related genes, which makes this anti-rheumatic drug a good candidate for new medicines against histoplasmosis. Author summary: Histoplasmosis is a serious disease caused by the fungus Histoplasma capsulatum, which can be life-threatening and has limited treatment options. In this study, we investigated the potential of auranofin, a drug originally approved for treating rheumatoid arthritis, to combat H. capsulatum. We tested auranofin against different strains of the fungus and found that it effectively inhibited fungal growth. This drug was also effective in killing the fungus within cells from the immune system and provided protection in an experimental animal model. Furthermore, auranofin reduced the expression of several genes associated with the fungus's ability to cause disease. These genes are involved in critical functions such as detoxifying harmful substances and maintaining cellular structures. By suppressing these genes, auranofin hampers the fungus's ability to survive and cause infection. These findings suggest that auranofin could be repurposed as a treatment for histoplasmosis, offering a new avenue for therapy against this challenging infection. This research is significant because it highlights the potential of existing drugs to treat other diseases, broadening our arsenal of available treatments and contributing to better healthcare solutions. [ABSTRACT FROM AUTHOR]

Edible insects are receiving increased attention as a new food source, although research on their implementation in confectionary products remains scarce. The study analyzed the chemical composition, physical parameters, antioxidative, and sensory characteristics of oatmeal cookies reformulated with yellow mealworm larvae (Tenebrio molitor L.; TM) at 0% (TM0), 10% (TM10), and 30% (TM30). The inclusion of TM in the cookie recipe increased the protein and fat content, improved the ratio of n-6/n-3 acids, and raised oleic acid levels while reducing palmitic acid. Oatmeal cookies were rich in K and P, and including TM significantly increased the content of most minerals, except for Mn and Na. The cookies held significant antioxidant capacity that increased as the concentration of TM increased due to hydrophilic antioxidants. Although lightness decreased with the increase in mealworm substitution, the yellowness, chroma, and hue angle remained similar for TM0 and TM10. The TM30 cookies were significantly darker and softer, which was further confirmed by panelists. The cookie formulation effectively masked the taste and smell of TM since there were no evident differences between the control and TM10 cookies. Cookies with TM30 received high enough ratings to be considered attractive if differentiated sensory characteristics are desired. [ABSTRACT FROM AUTHOR]

This study was aimed to investigate the effects of replacing dietary fish meal (FM) with defatted yellow mealworm (Tenebrio molitor) meal (DYM) on growth performance, intestinal health, serum immune, and antioxidant indexes of juvenile Chinese mitten crab (Eriocheir sinensis). Four hundred juvenile Chinese mitten crabs (4.94 ± 0.08 g) were randomly distributed into five groups in quadruplicate (20 crabs per tank), and each group was fed with diets that replaced FM with DYM at 0% (CON, containing 200 g/kg FM), 25% (DYM25), 50% (DYM50), 75% (DYM75), and 100% (DYM100) for 8 weeks, respectively. The results showed that the growth, serum immune and antioxidant indexes, digestive enzyme activities, intestinal histology, and microbiota composition of DYM25, DYM50, and DYM75 groups all reached the similar level as the CON group. While when 100% fishmeal was replaced, significantly decreased the final body weight (FBW), weight gain (WG), serum alkaline phosphatase (AKP), acid phosphatase (ACP), lysozyme (LZM), glutathione peroxidase (GSH‐Px), total antioxidant capacity (T‐AOC), and total superoxide dismutase (T‐SOD) activities, hepatopancreas protease activity, mid‐intestine folds height and number (P < 0.05), significantly increased the feed conversion ratio (FCR), serum malondialdehyde (MDA) content, and the abundance of intestinal harmful bacteria Shewanella (P < 0.05). Overall, these results suggest that 75% dietary FM (150 g/kg) can be effectively replaced by DYM without negative impact on the growth performance, intestinal health, serum immune, and antioxidant indexes of juvenile E. sinensis. [ABSTRACT FROM AUTHOR]

This study explores the potential of Tenebrio molitor larvae to valorize apple peels and assesses larval fermentation's impact on phenolics, growth potential and physicochemical properties of the larvae. Corn flour and apple peel were mixed in different ratios (1:1, 1:2, 1:4), and fermentation was conducted for 12 days. Significant changes occurred in the 1:1 ratio (EMB); larval weight increased by 62.2% compared to 58.6% in the control. After 12 days, the larvae showed increased ash, protein and carbohydrate contents, but reduced fat content. The phenolic content and antioxidant activities of the EMB medium significantly increased compared to the initial values, reaching their maximum level on day 8. Four quercetin derivatives were detected: quercetin-3-rutinoside, quercetin-3-O- glucoside, quercetin-3-O-galactoside and quercitrin. After 8 days, the amounts of quercitrin and quercetin-3-O-glucoside increased significantly. These findings suggest that T. molitor larvae can convert food waste into valuable functional food ingredients through phenolic release or conversion. [ABSTRACT FROM AUTHOR]

The use of edible insect protein in food products is contingent on their biological effects. Conventional protein extraction methods are not only time‐consuming and costly but also energy‐intensive. There is a need for alternative techniques that maintain the bioactivities of insect proteins and are environmentally sustainable. This study compares the health functionality of mealworm (Tenebrio molitor larvae) concentrates obtained by conventional methods—alkali and salt (MS) extraction—and nonconventional methods—enzyme (ME) and screw press (MP)—to enhance their applicability despite lower protein concentration. Overall, MP exhibited the highest essential amino acids content, whereas ME showed the highest in vitro digestibility, total phenolic contents, and antioxidant capacities among all the concentrates. ME also had a significant cell proliferative capacity at concentrations ≥500 µg/mL. MS significantly inhibited tumor necrosis factor‐alpha and interleukin‐1beta secretion in lipopolysaccharide‐treated Hep3B cells compared to other samples. As for anti‐hyperglycemia effects, treatment with MS and ME for 2 and 5 min significantly increased the p‐Akt/Akt ratio (MS, 1.34‐ and 1.61‐fold; ME, 2.26‐ and 2.70‐fold, respectively). In conclusion, enzyme treatment enhanced nutritional value and antioxidant capacity, whereas salt treatment potentially contributed to anti‐inflammatory and anti‐hyperglycemia activities. Hybrid extraction techniques combining conventional and nonconventional methods are suggested based on target applications, considering health benefits, environmental impact, costs, and efficiencies. Practical Application: Four mealworm protein extraction methods (alkali/salt/enzyme/screw press) were compared for their nutritional and biological properties. Alkali extraction enhanced protein content, enzyme treatment improved nutritional value and antioxidant capacity, and salt‐assisted extraction exhibited immunomodulatory effects in vitro. Notably, enzyme and salt treatments produced protein concentrates with significant antidiabetic and anti‐hyperglycemic properties. [ABSTRACT FROM AUTHOR]

Aims Aeromonas hydrophila , a Gram-negative bacterium, is ubiquitously found in many aquatic habitats, causing septicemia in humans and fishes. Attributed to abuse or misuse of conventional antimicrobial drug usage, antimicrobial resistance is at an alarming rise. There is an available alternative strategy to bacterial resistance to antimicrobials, which is inhibition of virulence and pathogenicity employing quorum sensing inhibitors (QSIs). Hence, actinomycin D's effectiveness against A. hydrophila SHAe 115 as a QSI was investigated in decreasing virulence factors and preventing biofilm formation. Methods and results Actinomycin D, belongs to the QSI combating Pseudomonas aeruginosa PAO1 originally isolated from an entophytic actinomycete (Streptomyces cyaneochromogenes RC1) in Areca catechu L. In the present work, further investigations were carried out to assess the effect of actinomycin D at subminimal inhibitory concentrations (sub-MICs), QS-regulated virulence factors, and biofilm inhibition strategies. Intrinsic properties encompassing inhibition of the production of protease and hemolysin and subsequent activities on biofilm formation and eradication of mature biofilm were established along with weakened swimming and swarming motilities in A. hydrophila SHAe 115. In the Tenebrio molitor survival assay, actinomycin D effectively reduced the virulence and pathogenicity of A. hydrophila , resulting in elimination of mortality. However, the hydrolysate of actinomycin D, 2-hydroxy-4,6-dimethyl-3-oxo-3H-phenoxazine-1,9-dicarboxylic acid (HDPD), had lost the QSI activity in A. hydrophila. Conclusions Actinomycin D was proved as a viable QSI in lessening A. hydrophila ' s the virulence and pathogenicity, as evident from our research findings [ABSTRACT FROM AUTHOR]

Simple Summary: Xenorhabdus is a bacterial genus that symbioses with entomopathogenic nematodes, specifically classified within Steinernema. These nematodes transport the bacteria into target insects, where the bacteria suppress the host's immune responses and induce septicemia. Within the cadaver of the insect, the nematodes reproduce and re-establish their association with the symbiotic bacteria. This study identifies significant variability in insecticidal virulence across different Xenorhabdus species or strains. This variability arises from differences in their growth rates and suppressive activities against host immune functions. Analysis of secondary metabolites revealed the presence of several peptides in the virulent strains. Further analysis of non-ribosomal peptide synthetase genes suggested cyclo Pro-Phe (cPF) as a virulence factor, which suppressed insect immune responses and enhanced the bacterial virulence. Entomopathogenic bacteria, classified into the genus Xenorhabdus, exhibit a dual lifestyle as mutualistic symbionts to Steinernema nematodes and as pathogens to a broad range of insects. Bacterial virulence depends on toxin proteins that induce toxemia and various immunosuppressive secondary metabolites that cause septicemia. Particularly, the immunosuppressive properties of Xenorhabdus bacteria determine the variability of their insecticidal activities. This study explored the role of peptide metabolites in virulence and its variation among six bacterial strains across three species: X. nematophila, X. bovienii, and X. hominickii. Initially, their virulence significantly varied against a susceptible lepidopteran host, Maruca vitrata, but showed less variation against a tolerant coleopteran host, Tenebrio molitor, with high median lethal bacterial doses. In M. vitrata, virulence was strongly correlated with bacterial growth rate and inhibitory activity against phospholipase A2. Secondly, the six strains differed in the compositions of their secreted secondary metabolites, analyzed by GC-MS following ethyl acetate extraction. Notably, there was significant variation in the production of di- or tetra-peptides. Highly virulent strains commonly produced the cyclic Pro-Phe (cPF). Thirdly, the expression of non-ribosomal peptide synthetase (NRPS) genes varied greatly among the strains. NRPS genes were minimally expressed in the tolerant T. molitor and highly expressed in the susceptible M. vitrata. In M. vitrata, specific NRPS genes were markedly expressed in the virulent strains. Finally, cPF demonstrated potent immunosuppressive activity against the cellular and humoral responses of M. vitrata. The addition of cPF significantly enhanced the virulence against the tolerant T. molitor. These findings suggest that immunosuppression is necessary for the pathogenicity of Xenorhabdus bacteria, wherein NRPS products play a critical role in suppressing immune-associated factors in target insects. [ABSTRACT FROM AUTHOR]

Fas‐associated death domain protein (FADD) is an apoptotic adapter molecule that recruits caspases and facilitates the formation of death‐inducing signaling complexes in mammals. In lower animals, FADD forms a complex with immune deficiency and death‐related ced‐3/Nedd2‐like caspase to elicit antimicrobial responses. In this study, we characterized the FADD sequence of Tenebrio molitor (TmFADD) using molecular informatics to understand its role in immune surveillance of the host against microorganisms. The 618 bp open reading frame of TmFADD encodes a polypeptide of 204 amino acids. The protein includes two promiscuous domains, the death‐effector domain and the death domain, found at the N‐ and C‐termini, respectively. TmFADD is clustered with the coleopteran FADD sequences in the phylogenetic tree. Homology‐based structural analysis showed an α‐helical model with a QMEAN score of 0.58. The expression of TmFADD mRNA was conspicuous in the larval and early pupal stages. TmFADD mRNA was distributed in the immune tissues of the larva and was found predominately in the gut of the adult. Infection of the host with Candida albicans, Escherichia coli or Staphylococcus aureus increased the expression of TmFADD mRNA, suggesting that these microorganisms trigger the innate immunity of the host. The silencing of TmFADD transcripts resulted in an increased susceptibility of T. molitor larvae to infection with E. coli, but not to infection with C. albicans or S. aureus. Hence, these results indicate that FADD plays a role in the defense of T. molitor and could open avenues for understanding insect immunity. [ABSTRACT FROM AUTHOR]

A new approach to supplying foods and feeds that are high in protein has emerged in the form of insect farming. Insect‐farmed food may also serve as part of a sustainable diet for humans. The mealworm Tenebrio molitor L. (Coleoptera: Tenebrionidae) is the most widely consumed insect worldwide. In this study, 10 larval diets were tested in the laboratory to determine their suitability for mass‐feeding mealworms at 28 °C and 60–65% r.h., in a completely randomized design. Various larval diets had a significant impact on the biological features of T. molitor. The larvae, pupae, and adults were greater on diets containing wheat bran alone and wheat bran in combination with maize and porridge. Larval mortality was significantly higher (60.7%) on a diet with porridge alone, compared to a control diet, followed by diets with porridge in combination with barley (55.6%) or maize (50.6%). Sex ratio was also affected by the tested larval diets. Female hatch (65%) was higher than male hatch (35%) on diet containing wheat bran alone as compared to all other diets. The findings contribute to optimizing mealworm rearing practices for sustainable food production and promote the potential use of mealworms as a viable protein source – especially livestock diets based on mealworm reared on wheat bran show promise. [ABSTRACT FROM AUTHOR]

Surfactants can be used as nanoparticle stabilizing agents. However, since synthetic surfactants are not economically viable and environmentally friendly, biosurfactants are emerging as a green alternative for the synthesis and stabilization of nanoparticles. Nanoparticles have been applied in several areas of industry, such as the production of biomedical and therapeutic components, packaging coating, solar energy generation and transmission and distribution of electrical energy, among others. The aim of this study was to synthesize, in a simple and green way, silver nanoparticles (AgNPs) using the biosurfactant produced by Candida lipolytica UCP 0899 as a stabilizer. AgNPs were examined and morphologically characterized using the techniques of ultraviolet–visible spectroscopy (UV–visible), scanning electron microscopy (SEM), zeta potential and energy dispersive X-ray spectroscopy (EDS). Newly formed silver nanoparticles showed a maximum UV–visible absorption peak at 400 nm, while a shift to 410 nm was observed in those stored for 120 days. SEM micrograph confirmed the formation of nanoparticles with an average size of 20 nm and with a predominant spherical structure, while a zeta potential of −60 mV suggested that the use of the biosurfactant promoted their stability. Stabilized nanoparticles were tested for their antimicrobial activity against bacterial isolates of Pseudomonas aeruginosa, Staphylococcus aureus, Escherichia coli and Enterobacter sp., as well as fungal isolates of Candida albicans and Aspergillus niger. At a concentration of 16.50 µg/mL, AgNPs inhibited the growth of all target microorganisms according to the following decreasing order: E. coli (95%), S. aureus, C. albicans (90%), A. niger (85%), Enterobacter sp. (75%) and P. aeruginosa (71%). These results suggest the potential use of the biosurfactant as a stabilizer of silver nanoparticles as an antimicrobial agent in different industrial sectors. Furthermore, the in vivo toxicity potential of biosurfactants was evaluated using the Tenebrio molitor model. The larvae were treated with concentrations in the range of 2.5, 5.0 and 10 g/L, and no mortality was observed within the 24 to 72 h period, demonstrating non-toxicity within the tested concentration range. These findings support the safety, efficacy and non-toxicity of biosurfactant-stabilized nanoparticles. [ABSTRACT FROM AUTHOR]

The objective of this study was to explore the impacts of various ultrasonic powers (0, 300, 500, 700, and 900 W) on the structure and functional attributes of the myofibrillar protein (MP) of Tenebrio molitor. As the ultrasonic intensity escalated, the extraction efficiency and yield of the MP rose, while the particle size and turbidity decreased correspondingly. The reduction in sulfhydryl group content and the increase in carbonyl group content both suggested that ultrasonic treatment promoted the oxidation of the MP to a certain extent, which was conducive to the formation of a denser and more stable gel network structure. This was also affirmed by SEM images. Additionally, the findings of intrinsic fluorescence and FTIR indicated that high-intensity ultrasound significantly altered the secondary structure of the protein. The unfolding of the MP exposed more amino acid residues, the α-helix decreased, and the β-helix improved, thereby resulting in a looser and more flexible conformation. Along with the structural alteration, the surface hydrophobicity and emulsification properties were also significantly enhanced. Besides that, SDS–PAGE demonstrated that the MP of T. molitor was primarily composed of myosin heavy chain (MHC), actin, myosin light chain (MLC), paramyosin, and tropomyosin. The aforementioned results confirmed that ultrasonic treatment could, to a certain extent, enhance the structure and function of mealworm MP, thereby providing a theoretical reference for the utilization of edible insect proteins in the future, deep-processing proteins produced by T. molitor, and the development of new technologies. [ABSTRACT FROM AUTHOR]

Mealworms are one of the most economically important insects in large-scale production for human and animal nutrition. Densoviruses are highly pathogenic for invertebrates and exhibit an extraordinary level of diversity which rivals that of their hosts. Molecular, clinical, histological, and electron microscopic characterization of novel densovirus infections is of utmost economic and ecological importance. Here, we describe an outbreak of densovirus with high mortality in a commercial mealworm (Tenebrio molitor) farm. Clinical signs included inability to prehend food, asymmetric locomotion evolving to nonambulation, dehydration, dark discoloration, and death. Upon gross examination, infected mealworms displayed underdevelopment, dark discoloration, larvae body curvature, and organ/tissue softness. Histologically, there was massive epithelial cell death, and cytomegaly and karyomegaly with intranuclear inclusion (InI) bodies in the epidermis, pharynx, esophagus, rectum, tracheae, and tracheoles. Ultrastructurally, these InIs represented a densovirus replication and assembly complex composed of virus particles ranging from 23.79 to 26.99 nm in diameter, as detected on transmission electron microscopy. Whole-genome sequencing identified a 5579-nucleotide-long densovirus containing 5 open reading frames. A phylogenetic analysis of the mealworm densovirus showed it to be closely related to several bird- and bat-associated densoviruses, sharing 97% to 98% identity. Meanwhile, the nucleotide similarity to a mosquito, cockroach, and cricket densovirus was 55%, 52%, and 41%, respectively. As this is the first described whole-genome characterization of a mealworm densovirus, we propose the name Tenebrio molitor densovirus (TmDNV). In contrast to polytropic densoviruses, this TmDNV is epitheliotropic, primarily affecting cuticle-producing cells.

Preventing disease and maintaining the health of the elderly are crucial goals for an aging population, with obesity and immune function restoration being of paramount importance. Obesity, particularly visceral obesity characterized by excessive fat accumulation around the abdominal organs, is linked to chronic conditions such as diabetes, hypertension, cardiovascular diseases, and immune dysfunction. Globally, obesity is considered a disease, prompting significant research interest in its treatment. Therefore, it is essential to explore potential therapeutic and preventive strategies to address obesity and the decline in immune function brought about by aging. Tenebrio molitor larvae (TML), commonly known as ‘mealworms,’ are rich in unsaturated fatty acids, including oleic and linoleic acids, and essential amino acids, such as isoleucine and tyrosine. In this study, we aimed to investigate the effects of the consumption of TML oil and mealworm fermented extract (MWF-1) on obesity and immunological changes in aged obese mice. Our data showed reduced body fat in 23-week-old C57BL/6 mice fed processed TML products for 6 weeks. Additionally, the characteristically high levels of serum triglycerides decreased by treating with TML oil. The immune responsiveness results confirmed an increase in B cells by treating with MWF-1, while cytokine levels (interferon-gamma, tumor necrosis factor-alpha, interleukin-2, and −6) were restored to levels similar to young mice. These results suggest that TML oil and MWF-1 are promising dietary supplements for addressing obesity and restoring immune function.

Production of insects as animal protein source has increased recently but the information on nutrient requirements for optimal growth is still scarce. The effects of carbohydrate composition of the substrate on growth performance and chemical composition of Tenebrio molitor larvae were evaluated. Three substrates based on different proportions of wheat grain, wheat bran and soybean meal were formulated to contain three starch to neutral detergent fibre (NDF) ratios: low (1.0; LSF), medium (1.2; MSF) and high (1.4; HSF), at a common N level. Each treatment was replicated five times in trays containing 23 g of substrate and 40 larvae (2.95 mg average weight) each. Weight of the larvae and the substrate remaining per tray were weekly monitored from 21 to 49 days of experiment and larvae within the same experimental treatment were pooled at the end of the trial for chemical analysis. No treatment differences were observed for larval growth or mortality (p > 0.05). The starch to NDF ratio in the substrate did not affect larval composition in terms of dry matter, nitrogen or ether extact contents or the amino acid composition of the protein fraction. Within the range of ingredient composition considered, the starch to NDF ratio in the substrate has a minor influence on growth performance and chemical composition of T. molitor larvae.

In the last decade, great attention was placed on insects to increase feed-food production without negatively affecting the environment. In this research study we compare three different insect species (Alphitobius diaperinus, Tenebrio molitor, and Zophobas morio - lesser mealworm, mealworm, and superworm), fed the same substrate, on the chemical composition, fatty acid (FA) profile, antioxidant content, and microbiological loads. Superworm larvae show higher dry matter (38.06%) and ether extract (17.65%) contents followed by mealworm and lesser mealworm larvae (32.77%, 27.11% and 13.86%, 10.78%, respectively). No differences were detected in the crude protein and ash content. Superworm larvae showed the highest content of SFA (41.43% vs 39.16% and 28.52% of total FA, in lesser mealworm and mealworm, respectively), while mealworm larvae were the richest in MUFA (40.61% vs 34.38% and 32.98% of total FA, in super and lesser mealworm, respectively) and PUFA (29.05% vs 22.29% and 21.21% of total FA in super and lesser mealworm, respectively). Anyhow, in all the larvae the three more representative fatty acids were oleic acid, linoleic acid, and palmitic acid. The least beneficial ratio of n-6/n-3 was detected in Alphitobius diaperinus larvae (53.84), while Zophobas morio larvae showed the healthier ratio (16.04). The antioxidant contents determination revealed a linkage to the fatty acids content. Low differences were determined in microbiological loads of the larvae. The characteristics of the insects revealed the great potential of these three species highlighting the capacities to respond to different requests derived from the food and feed sectors.Highlights Superworm larvae showed the highest content of SFA Mealworms larvae were the richest in PUFA The fat-soluble vitamin content followed the fatty acids content

Numerous insect species and their associated microbial pathogens are exposed to elevated CO2 concentrations in both artificial and natural environments. However, the impacts of elevated CO2 on the fitness of these pathogens and the susceptibility of insects to pathogen infections are not well understood. The yellow mealworm, Tenebrio molitor, is commonly produced for food and feed purposes in mass-rearing systems, which increases risk of pathogen infections. Additionally, entomopathogens are used to control T. molitor, which is also a pest of stored grains. It is therefore important to understand how elevated CO2 may affect both the pathogen directly and impact on host-pathogen interactions. We demonstrate that elevated CO2 concentrations reduced the viability and persistence of the spores of the bacterial pathogen Bacillus thuringiensis. In contrast, conidia of the fungal pathogen Metarhizium brunneum germinated faster under elevated CO2. Pre-exposure of the two pathogens to elevated CO2 prior to host infection did not affect the survival probability of T. molitor larvae. However, larvae reared at elevated CO2 concentrations were less susceptible to both pathogens compared to larvae reared at ambient CO2 concentrations. Our findings indicate that whilst elevated CO2 concentrations may be beneficial in reducing host susceptibility in mass-rearing systems, they may potentially reduce the efficacy of the tested entomopathogens when used as biological control agents of T. molitor larvae. We conclude that CO2 concentrations should be carefully selected and monitored as an additional environmental factor in laboratory experiments investigating insect-pathogen interactions. [ABSTRACT FROM AUTHOR]

In the context of the growing demand for alternative protein sources with the growth of the human population and increasing ecological awareness, the rearing of yellow mealworm larvae (Tenebrio molitor) is a promising option for the production of sustainable protein. The article presents a comprehensive approach to planning and scheduling the production of yellow mealworm larvae in a small enterprise, focusing on the organizational, technical, and economic aspects of the production process. The production installation, the method of rearing using an automated feeding system, and the monitoring of larvae development were described and an attempt was made to identify the key parameters of the process that affect its efficiency. Particular attention was paid to the calculation algorithm implemented in the spreadsheet, which allows the selection of the production batch size and the frequency of their launch, so as to maximize the available capacity of storage racks for cuvettes. In addition, the article analyses logistical challenges related to the production of larvae, including transport activities in order to meet, among others, the demand for feed. Finally, the estimation of revenues and economic indicators, such as profitability and return on investment, is presented, pointing to the need for further improvements in the production process and cost optimization to achieve favorable financial results. The results of the research emphasize the potential of rearing yellow mealworm larvae as a sustainable source of protein while simultaneously pointing to key areas that require further research and development. [ABSTRACT FROM AUTHOR]

Iron is an essential mineral that supports biological functions like growth, oxygen transport, cellular function, and hormone synthesis. Insufficient dietary iron can lead to anemia and cause fatigue, cognitive impairment, and poor immune function. Animal-based foods provide heme iron, which is more bioavailable to humans, while plant-based foods typically contain less bioavailable non-heme iron. Edible insects vary in their iron content and may have heme or non-heme forms, depending on their diet. Edible insects have been proposed as a protein source that could address issues of food insecurity and malnutrition in low resource contexts; therefore, it is important to understand the bioavailability of iron from insect-based foods. In this study, we used Inductively Coupled Plasma and Mass Spectrometry (IPC-MS) and Caco-2 cell culture models to compare the soluble and bioavailable iron among five different lab-produced tempeh formulations featuring Tenebrio molitor (mealworm) with their non-fermented raw ingredient combinations. Finally, we compared the iron bioavailability of a mealworm tempeh with two sources of conventional beef (ground beef and sirloin steaks) and two commercially available plant-based meat alternatives. The results show that while plant-based meat alternatives had higher amounts of soluble iron, particularly in the Beyond Burger samples, the fermented mealworm-based tempeh had greater amounts of bioavailable iron than the other samples within the set. While all the samples presented varying degrees of iron bioavailability, all products within the sample set would be considered good sources of dietary iron. [ABSTRACT FROM AUTHOR]

This study aimed to assess the effect of killing (blanching and freezing) followed by culinary processing on the microbiological quality of Tenebrio molitor and Gryllus assimilis. These insects were subjected to starvation before killing, which does not ensure sufficient microbiological safety. Therefore, technological or culinary processing of insects is necessary before consumption. For the subsequent processing of insects, boiling, drying, roasting, and microwave treatment were used. Nine categories of microbiological parameters were selected as indicators of hygienic quality. All identification and enumeration were performed using ISO-compliant methods. The results showed that killing insects by blanching or freezing alone does not ensure sufficient microbiological quality, and therefore, further culinary processing is necessary. However, all subsequent culinary treatments applied in this study were able to reduce the microbial load significantly. [ABSTRACT FROM AUTHOR]

Waste from non-degradable packaging materials poses a serious environmental risk and has led to interest in developing sustainable bio-based packaging materials. Sustainable packaging materials have been made from diverse naturally derived materials such as bamboo, sugarcane, and corn starch. In this study, we made a sustainable packaging film using chitosan extracted from the biomass of yellow mealworm (Tenebrio molitor) shell waste. The extracted chitosan was used to create films, cross-linked with citric acid (CA) and with the addition of glycerol to impart flexibility, using the solvent casting method. The successful cross-linking was evaluated using Fourier-Transform Infrared (FTIR) analysis. The CA cross-linked mealworm chitosan (CAMC) films exhibited improved water resistance with moisture content reduced from 19.9 to 14.5%. Improved barrier properties were also noted, with a 28.7% and 10.2% decrease in vapor permeability and vapor transmission rate, respectively. Bananas were selected for food preservation, and significant changes were observed over a duration of 10 days. Compared to the control sample, bananas packaged in CAMC pouches exhibited a lesser loss in weight because of excellent barrier properties against water vapor. Moreover, the quality and texture of bananas packaged in CAMC pouch remained intact over the duration of the experiment. This indicates that adding citric acid and glycerol to the chitosan structure holds promise for effective food wrapping and contributes to the enhancement of banana shelf life. Through this study, we concluded that chitosan film derived from mealworm biomass has potential as a valuable resource for sustainable packaging solutions, promoting the adoption of environmentally friendly practices in the food industry. [ABSTRACT FROM AUTHOR]

The growing world population necessitates the implementation of appropriate processing technologies for edible insects. The objective of this study was to examine the impact of distinct drying techniques, including convective drying at 70 °C (70CD) and 90 °C (90CD) and freeze-drying (FD), on the drying kinetics, physical characteristics (water activity, color), chemical characteristics (chemical composition, amino acid profile, oil properties, total polyphenol content and antioxidant activity, mineral composition, FTIR), and presence of hazards (allergens, microorganisms) of blanched yellow mealworm larvae. The freeze-drying process results in greater lightness and reduced moisture content and water activity. The study demonstrated that the freeze-dried insects exhibited lower contents of protein and essential amino acids as compared to the convective-dried insects. The lowest content of total polyphenols was found in the freeze-dried yellow mealworm larvae; however, the highest antioxidant activity was determined for those insects. Although the oil isolated from the freeze-dried insects exhibited the lowest acid and peroxide values, it proved to have the lowest PUFA content and oxidative stability. All the samples met the microbiological criteria for dried insects. The results of the study demonstrate that a high temperature during the CD method does not result in the anticipated undesirable changes. It appears that freeze-drying is not the optimal method for preserving the nutritional value of insects, particularly with regard to the quality of protein and oil. [ABSTRACT FROM AUTHOR]

Simple Summary: Mealworms (Tenebrio molitor) have a great ability to bioconvert vegetable by-products used as feed into body mass. Rice straw is a vegetable by-product that is difficult to dispose of and causes environmental problems. The use of physicochemical or enzymatic treatments to improve the digestibility of these by-products can increase the performance of mealworms in terms of yield. In this study, mealworm larvae were reared on diets formulated with rice straw and rice straw subjected to a combined treatment of laccase enzyme, ultrasound, and ascorbic acid to evaluate the impact on the growth performance and digestibility of T. molitor. The combined sonication, laccase enzyme, and ascorbic acid treatment of rice by-products facilitated their use by T. molitor larvae, increasing the weight gain, feed conversion ratio, and conversion efficiency of ingested feed. The use of treatments capable of improving the usefulness of vegetable by-products opens the possibility of developing new methodologies for their use for insect feed. The development of reuse processes for plant by-products for both animal and human food offers numerous possibilities for quality-of-life improvements that align with a circular economy model. For this reason, we divided this study into two experiments. First, we designed a combined treatment consisting of laccase, ultrasound, and ascorbic acid to hydrolyze rice straw plant fibers and used the resulting feed as the basis for T. molitor diets. Second, we formulated diets with different inclusion levels (0%, 25%, 50%, 75%, and 100%) of rice straw and treated rice straw to assess their impact on larvae growth and diet digestibility. For each treatment, six replicates were employed: four for the growth–performance–digestibility trial and two for complementary uric acid determination tests. The combined laccase enzyme, ultrasound, and ascorbic acid treatment hydrolyzed 13.2% of the vegetable fibers. The diets containing treated rice straw resulted in higher larvae weight and a better feed conversion ratio; however, reaching 100% by-product inclusion values led to similar results between both diets. In conclusion, these treatments improve the potential of low-nutritional-value vegetable by-products as part of a T. molitor diet, opening the possibility of new methodologies for the use of recalcitrant vegetable by-products for insect rearing. [ABSTRACT FROM AUTHOR]

Simple Summary: Interest in large-scale rearing edible insects such as beetles, crickets, and flies has increased significantly in recent years. These insects are now used for various purposes: as food and feed, managing organic and plastic waste, detoxifying environments, producing biofuels, and even in cosmetics and pharmaceuticals. These applications consist of feeding insects with waste materials that are not widely used, transforming them into valuable products like food, feed, and fertilizer. The insect's digestive system is therefore the keystone of these developing processes. Digestion is partly carried out by the insect itself and partly by gut-associated microorganisms. Their respective roles remain a needed research area, and it is now clear that the community of microorganisms can adapt, enhance, and extend the insect's ability to digest and detoxify their feed. Despite this, these species are surprisingly autonomous, with no mandatory association with microorganisms required for digestion. On the contrary, microbiota largely differ for the same species, and are mostly shaped by the host's environment and diet. This natural flexibility offers the prospect of targeting and developing novel associations between insects and microorganisms to create mass-reared strains tailored to manage specific by-products and industrial applications. The interest in edible insects' mass rearing has grown considerably in recent years, thereby highlighting the challenges of domesticating new animal species. Insects are being considered for use in the management of organic by-products from the agro-industry, synthetic by-products from the plastics industry including particular detoxification processes. The processes depend on the insect's digestive system which is based on two components: an enzymatic intrinsic cargo to the insect species and another extrinsic cargo provided by the microbial community colonizing—associated with the insect host. Advances have been made in the identification of the origin of the digestive functions observed in the midgut. It is now evident that the community of microorganisms can adapt, improve, and extend the insect's ability to digest and detoxify its food. Nevertheless, edible insect species such as Hermetia illucens and Tenebrio molitor are surprisingly autonomous, and no obligatory symbiosis with a microorganism has yet been uncovered for digestion. Conversely, the intestinal microbiota of a given species can take on different forms, which are largely influenced by the host's environment and diet. This flexibility offers the potential for the development of novel associations between insects and microorganisms, which could result in the creation of synergies that would optimize or expand value chains for agro-industrial by-products, as well as for contaminants. [ABSTRACT FROM AUTHOR]

Simple Summary: In this study, we investigated the impact of incorporating freeze-dried mealworm larvae powder (Tenebrio molitor) into wheat bread on its quality, nutritional value, and consumer acceptance. Mealworms represent a sustainable protein source that can enhance the nutritional profile of foods. Bread was prepared with varying concentrations of mealworm powder (5%, 10%, and 15%), which significantly increased the bread's protein and fat content, particularly in terms of essential amino acids and beneficial fatty acids. However, higher levels of mealworm powder also resulted in darker bread and decreased consumer acceptance, as the altered taste and texture were perceived less favourably. This study emphasizes that while mealworm powder can enhance the nutritional value of bread, it is crucial to balance these benefits with sensory qualities to maintain consumer appeal. The findings suggest that mealworm powder could be a valuable ingredient for producing nutritionally enriched bread, provided that consumer preferences are carefully considered. This research contributes to the growing body of literature on the use of insects as sustainable food ingredients. The research context involves analyzing the potential benefits derived from integrating insect protein into everyday food items. Utilizing methods consistent with established food science protocols, wheat bread was prepared with variations of 0%, 5%, 10%, and 15% Tenebrio molitor larvae powder, derived from larvae cultivated on brewery spent grain. A substrate selected for its superior nutritional content and a substrate with agar–agar gels were used. The tests included basic bread tests; sugar, acrylamide, amino, and fatty acid (FA) tests; and sensory acceptability. The results have shown that the acrylamide levels in bread with larvae remained below harmful thresholds, suggesting that using T. molitor can be a safe alternative protein source. The incorporation of powdered T. molitor larvae (p-TMLs) into bread was observed to increase certain sugar levels, such as glucose, particularly at higher larval concentrations. The addition of T. molitor significantly raised the protein and fat levels in bread. The inclusion of larvae enriched the bread with essential amino acids, enhancing the nutritional value of the bread significantly. The FA profile of the bread was altered by the inclusion of p-TMLs, increasing the levels of monounsaturated FAs. Despite the nutritional benefits, higher concentrations of larvae decreased the sensory acceptability of the bread. This suggests that there is a balance to be found between enhancing the nutritional content and maintaining consumer appeal. These findings highlight the potential for using p-TMLs as a sustainable, nutritious ingredient in bread making, although the sensory qualities at higher concentrations might limit consumer acceptance. [ABSTRACT FROM AUTHOR]

The study aimed to be able to incorporate mealworm powder into yoghurts to increase protein content. Tenebrio molitor is gaining popularity as an alternative protein source. In the face of a growing human population and the associated challenges of sustainable nutrition, mealworms offer a promising solution. The mealworm is distinguished by its high protein content and for being rich in essential amino acids, vitamins, and minerals, making it a valuable component of diet. Among others, chemical composition, colour, texture, degree of syneresis, sensory analysis, and microbiological analysis were analysed. As expected, the addition of insect powder increased the protein content from 4.91% (0 TM) to 7.41% (5 TM). It also increased the fat content from 1.67% (0 TM) to 3.88% (5 TM). Furthermore, the addition of mealworm powder resulted in a significant change in the colour of the yoghurt to a darker colour, due to the dark brown colour of the powder. Food with added edible insects is increasingly available but is not always popular due to cultural and psychological barriers. Sensory analysis of yoghurts has shown that the more powder that is added, the less appealing the product becomes and the more bitter the taste. [ABSTRACT FROM AUTHOR]

Over the past 2 decades, the potential of insects as food and feed has been recognized globally. Insects as feed ingredients can improve sustainability because of their lower greenhouse gas emissions and their potential to transform organic wastes into high-quality feed rich in nutrients. However, currently, the practical use of insects as food or feed is limited by the high costs of insect production. A great deal of effort is required to improve the rearing technology necessary to establish the principles of insect farming. Several insect species have become industrialized using existing methods of production. The most common industrialized insect species intended as feed and food include the yellow mealworm, Tenebrio molitor L. (Coleoptera: Tenebrionidae); the house cricket, Acheta domesticus L. (Orthoptera: Gryllidae); the black soldier fly, Hermetia illucens L. (Diptera: Stratiomyidae); and the house fly, Musca domestica L. (Diptera: Muscidae). This review focuses on describing the existing rearing methods for these 4 insect species, which may provide a basis for future research to enhance insect production capabilities. [ABSTRACT FROM AUTHOR]

An in vivo trial was conducted to determine the apparent digestibility coefficients (ADCs) of insect meals for rainbow trout, Oncorhynchus mykiss. Rainbow trout (approximately 370 g ± 23 g, mean ± SD initial weight) were stocked 25 per tank into 400-liter tanks. Fish were fed a reference diet, or 1 of 5 test diets created by blending the reference diet in a 70:30 ratio (dry-weight basis) with menhaden fish meal (MFM), 2 house cricket (Acheta domesticus) meals (cricket A and cricket B), Galleria mellonella meal, and yellow mealworm (Tenebrio molitor) meal. Diets were assigned to 3 replicate tanks of fish and fed twice daily for 14 days prior to fecal collection. Ingredients, diets, and fecal matter were analyzed in duplicate for proximate, mineral, and amino acid composition. House cricket meals were 67.3% and 69.0% protein (CP) and 16.6% and 17.1% lipid (CL), for house cricket A and B, respectively. Yellow mealworm meal contained 56.5% CP and 27.7% CL, and G. mellonella larvae meal contained 32.5% CP and 54.2% CL. Protein ADCs were 78.9 for G. mellonella larvae meal, 78.0 for yellow mealworm meal, and 76.5 for house cricket A and not different from the MFM protein ADC of 76.6, while house cricket B protein ADC was 65.8 and was significantly lower than the MFM protein ADC (F  = 7.39; df = 4,14; P  = 0.0049). Together, these nutritional values suggest house crickets, and yellow mealworms show promise as alternative protein sources in salmonid feeds, with the potential of G. mellonella as an alternative lipid source. [ABSTRACT FROM AUTHOR]

The utilization of yellow mealworm, Tenebrio molitor (Linnaeus, Coleoptera: Tenebrionidae), for food and feed is gaining interest globally. However, its production is hindered by expensive commercial diets. This study assessed mealworm growth performance, survival, bioconversion, and nutritional composition when fed on wheat bran (WB) with different inclusion levels (25%, 50%, 75%, and 100%) of Irish potato waste (PW). Results indicated that mealworms fed on diets with 25%–75% PW had increased body length and 1–2 times higher weight gain compared to sole WB and PW diets. The survival rate was 93%–94% across all diets. Mealworms fed on WB had a feed conversion ratio of 3.26, while the efficiency of diet conversion increased with PW inclusion levels. Mealworms fed on diets with 75% PW inclusion had the highest crude fat (48%) and energy levels (598 kcal/100 g), while sole WB produced mealworms with the highest crude protein (55%). The acid detergent fiber achieved using 100% WB was 2- to 3-fold higher, but the crude fiber and neutral detergent fiber did not vary significantly. Considerable amounts of lysine (1.6–2 mg/100 g), methionine (0.5–0.7 mg/100 g), leucine (1.4–2 mg/100 g), and threonine (0.8–1 mg/100 g) were achieved in the mealworm larvae. Our findings revealed that cheap agricultural by-products could be successfully used for the mass production of mealworms, substantially contributing to reduced production costs. Further exploration of the nutrient-dense mealworm larvae for the development of novel food and feed products is crucial. [ABSTRACT FROM AUTHOR]

Insect manure or "frass" has emerged as an alternative nutrient source for alleviating the dependence on fossil fuel-based fertilizers, reducing food waste, and promoting food security. Yet, research on insect frass chemical composition is in its infancy. Here, we assessed the chemical properties of yellow mealworm (Tenebrio molitor L.) frass compared with poultry litter (PL). Insect frass was obtained from the National Biological Control Laboratory (NBCL; IF-L) and an insect-rearing company (IF-C). PL was collected from facilities in Arkansas (PL-AR) and North Carolina (PL-NC). Samples were analyzed for pH, electrical conductivity, macro- and micronutrients, heavy metals, pathogens, and indicator microorganisms. On average, insect frass had 43% and 47% higher C and N than PL, respectively (P  < 0.05). Considering a 5 mg/ha application rate, IF-C can supply 159 kg N/ha, twice the N supply of PL-AR (78 kg/ha). IF-L had a 53% higher P supply than PL-NC. Mean K, Ca, S, and micronutrient contents were higher in PL than in frass (P  < 0.05), whereas As, Cd, Cr, and Pb were nearly absent in frass. Chemical composition and pathogens in fertilizer sources were largely affected by insect-rearing substrate and supplements used in poultry and insect production. Insect frass utilized in this study had optimum C and N rates relative to PL, suggesting a promising soil amendment for improving soil health and C sequestration, thus contributing to sustainable agricultural intensification and reuse of food waste in circular economies. [ABSTRACT FROM AUTHOR]

As the most numerous group of animals on Earth, insects are found in almost every ecosystem. Their useful role in the environment is priceless; however, for humans, their presence may be considered negative or even harmful. For years, people have been trying to control the number of pests by using synthetic insecticides, which eventually causes an increased level of resistance to applied compounds. The effects of synthetic insecticides have encouraged researchers to search for alternatives and thus develop safe compounds with high specificity. Using knowledge about the physiology of insects and the functionality of compounds of insect origin, a new class of bioinsecticides called peptidomimetics, which are appropriately modified insect analogues, was created. One promising compound that might be successfully modified is the thirteen amino acid peptide alloferon (HGVSGHGQHGVHG), which is obtained from the hemolymph of the blue blowfly Calliphora vicinia. Our research aimed to understand the physiological properties of alloferon and the activity of its peptidomimetics, which will provide the possibility of using alloferon or its analogues in the pharmaceutical industry, as a drug or adjuvant, or in agriculture as a bioinsecticide. We used alloferon and its three peptidomimetics, which are conjugates of the native peptide with three unsaturated fatty acids with various chain lengths: caprylic, myristic, and palmitic. We tested their effects on the morphology and activity of the reproductive system and the embryogenesis of the Tenebrio molitor beetle. We found that the tested compounds influenced the growth and maturation of ovaries and the expression level of the vitellogenin gene. The tested compounds also influenced the process of egg laying, embryogenesis, and offspring hatching, showing that alloferon might be a good peptide for the synthesis of effective bioinsecticides or biopharmaceuticals. [ABSTRACT FROM AUTHOR]

Solanine (SOL) and chaconine (CHA) are glycoalkaloids (GAs) produced mainly by Solanum plants. These plant secondary metabolites affect insect metabolism; thus, they have the potential to be applied as natural plant protection products. However, it is not known which GA concentration induces physiological changes in animals. Therefore, the aim of this study was to perform a quantitative analysis of SOL and CHA in the larvae of Tenebrio molitor using LC‒MS to assess how quickly they are eliminated or metabolised. In this experiment, the beetles were injected with 2 μL of 10−5 M SOL or CHA solution, which corresponds to a dosage range of 0.12–0.14 ng/mg body mass. Then, 0.5, 1.5, 8, and 24 h after GA application, the haemolymph (H), gut (G), and the remainder of the larval body (FB) were isolated. GAs were detected in all samples tested for 24 h, with the highest percentage of the amount applied in the FB, while the highest concentration was measured in the H sample. The SOL and CHA concentrations decreased in the haemolymph over time, while they did not change in other tissues. CHA had the highest elimination rate immediately after injection, while SOL slightly later. None of the GA hydrolysis products were detected in the tested samples. One possible mechanism of the detoxification of GAs may be oxidation and/or sequestration. They may be excreted by Malpighian tubules, with faeces or with cuticles during moulting. The results presented are significant because they facilitate the interpretation of studies related to the effects of toxic substances on insect metabolism. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate the impact of substituting a portion of feed with Tenebrio molitor (TM) and Elodea nuttallii (EN) on crayfish culture. A total of 270 crayfish (5.1 ± 0.4 g) were fed three different diet combinations (A: 100% feed; B: 80% feed + 10% TM + 10% EN; C: 75% feed + 15% TM + 10% EN) for 12 weeks. The findings demonstrated that group C had an important beneficial impact on the growth performance of crayfish. This was evidenced by a rise in digestive enzyme activity (trypsin, lipase, and cellulase) in the intestinal and hepatopancreas, as well as an upregulation in the expression of growth-related genes (ghsr, igfbp7, mhc, mlc1, mef2, and pax7) in the muscle. Furthermore, the assessment of the flesh quality of crayfish muscle in group C was conducted. The findings indicated a significant increase (p < 0.05) in the energy value (moisture, crude protein, and crude lipid) within the muscle. The levels of delicious amino acids (Glu, Ala, Ser, Gly, and Tyr) and polyunsaturated fatty acids (ARA, DHA) were enhanced, resulting in an improved nutritional profile and flavor of the muscle while maintaining the Σn-3/Σn-6 ratio. The remodeling of the intestinal microbiota (abundance of Proteobacteria and ratio of Firmicutes/Bacteroidota bacteria) also revealed improved growth performance. Additional research is necessary to ascertain whether excessive use of TM or EN feed substitution can have negative effects on crayfish culture. [ABSTRACT FROM AUTHOR]

This study aimed to assess the effect of the addition (2%) of soybean protein (SP) and insect flours derived from house crickets (Acheta domesticus, HCF) and yellow mealworm (Tenebrio molitor, YMF) in cooked sausages. The technological characteristics of the batter, the chemical composition of the sausages, their technological traits and lipid stability during refrigerated storage, as well as their sensory properties, were investigated. The SP, HCF and YMF batters displayed higher pH (p = 0.0025) and stability (p < 0.0001) but a darker colour (p < 0.0001) than the control samples. The addition of SP increased the plasticity of the batter (p = 0.0017), while YMF decreased its structural strength (p = 0.0274). Higher pH and darker colour were detected in SP-, HCF- and YMF-containing sausages; however, the effect of the alternative proteins depended on the duration of storage. The plasticity decreased in the insect-containing sausages (p = 0.0010) and increased over time (p = 0.0136), whereas the elasticity was lower in the YMF group (p < 0.0001). The protein and fat contents were higher (p < 0.0001) in the sausages containing alternative protein. TBARS content decreased over time in these groups. The HCF and YMF sausages received lower scores for their appearance, colour, texture, flavour and taste, suggesting the need for further technological interventions to make such products more attractive to consumers. [ABSTRACT FROM AUTHOR]

Historically, males have frequently been portrayed as the manipulative and deceptive gender, while females are often seen as adopting a coy and passive role. In this context, it is proposed that males use a terminal investment strategy, misleading females about their true poor condition, while females passively opt to mate with these deceptive males. However, we hypothesize that females in suboptimal condition may also engage in a terminal investment strategy by mimicking or enhancing their attractiveness to match that of females in better conditions. We studied this hypothesis in Tenebrio molitor, by subjecting females to three varying doses of lipopolysaccharides of Escherichia coli (LPS; 0.25, 0.5, or 1 mg ml-1), or three doses of the pro-oxidant Paraquat (PQ; 20, 40 or 80 mM), and subsequently assessing their survival and attractiveness to males. The LPS treatments and 20 mM of PQ had no significant effect on the survival or attractiveness of the females. However, females treated with 40 or 80 mM PQ survived fewer days compared to the control group. Those injected with 40 mM were more attractive than their control counterparts, while those treated with 80 mM were less attractive. Since the identical doses of LPS, which induce terminal investment in males, had no effect on females, we suggest sexual dimorphism in terminal investment. Furthermore, similar to males, if the stressor reaches a sufficiently high level, the signal becomes honest. These findings highlight how the quantity of stressors influences support for the terminal investment strategy in both males and females. Notably, this study challenges prevailing notions regarding gender roles in sexual selection, indicating that females, not just males, conceal their poor condition to attract mating partners. [ABSTRACT FROM AUTHOR]

The study aims to assess the impact of oven-drying and decontamination on crude protein concentration and in vitro crude protein digestibility of yellow mealworms. Two kilograms of 12-wk-old mealworm larvae were subjected to freezing prior to the drying process. Approximately 1.5 kg of mealworm larvae were divided into 3 groups and exposed to oven-drying at temperatures of 50 °C for 36 h, 60 °C, and 70 °C for 24 h each. At intervals of 2 h, sets of 3 replicates were withdrawn to record water loss. Consistent weight stabilization was observed at 36 h for 50 °C (T50), 18 h for 60 °C (T60), and 14 h for 70 °C (T70). The remaining 0.5 kg of mealworm larvae was divided and dried under treatments T50, T60, and T70. Each treatment was then split into 2 portions, with one portion subjected to 90 °C for 15 min (denoted as T50-90, T60-90, T70-90) to eliminate microbial contamination. The 6 treatments were then used to determine concentrations of dry matter, crude ash, crude protein, pre-caecal protein digestibility, and dry matter residues after neutral detergent fiber, acid detergent fiber, and acid detergent lignin treatments. No interaction was observed between drying and decontamination treatments (P  > 0.17). Pre-caecal crude protein digestibility increased with decreasing temperature (T50: 58% crude protein; T60: 51% crude protein; T70: 50% crude protein). Therefore, lower temperatures for longer times preserve crude protein digestibility. These findings are crucial for understanding how drying temperature and time impact protein bioavailability. [ABSTRACT FROM AUTHOR]

Simple Summary: Substances that are absent in the biosphere, but have been synthesized by humans in recent decades, are called xenobiotics. They are released into the environment in large volumes and can actively affect invertebrates and their intestinal parasites or commensals. Such an influence of xenobiotics on parasite–host relationships remained poorly studied until recently. In this article, the host–parasite system "larva of Tenebrio molitor—Gregarina polymorpha" under the influence of 24 organic compounds is investigated. We found that several substances increase the mortality of T. molitor larvae, and substances such as diphenyl ether, benzyl alcohol, catechol, and 3-aminobenzoic acid, on the contrary, reduce the number of parasites (G. polymorpha) without significantly affecting host insects (larva of T. molitor). Thus, various xenobiotics can destroy the parasite–host relationship, having a greater effect on the host in some cases and on the parasite in other cases. Environmental contamination with xenobiotics affects organisms and the symbiotic relations between them. A convenient object to study relationships between parasites and their hosts is the host–parasite system "Tenebrio molitor Linnaeus, 1758 (Coleoptera, Tenebrionidae)—Gregarina polymorpha (Hammerschmidt, 1838) Stein, 1848 (Eugregarinorida, Gregarinidae)". For this experiment, we took 390 T. molitor larvae and 24 organic compounds. Groups of mealworms, 15 in each, were subjected to those compounds for 10 days. Then, we recorded the vitality of both the larvae of T. molitor and G. polymorpha. To assess how G. polymorpha had affected the hosts' wellbeing, we looked for changes in the larvae's body mass and compared them to the number of gregarines in their intestines. The vitality of the larvae was inhibited by cyclopentanol and 2-naphthol. The intensity of gregarine invasion was reduced by diphenyl ether, benzyl alcohol, catechol, and 3-aminobenzoic acid. No effect on the number of gregarines was produced by 3,4,5-trihydroxybenzoic acid, cyclohexanemethanol, phenol, benzalkonium chloride, maleic anhydride, cyclohexanol, resorcin, benzoic acid, 2-methylfuran, terpinen-4-ol, 1-phenylethylamine, dibutyl phthalate, 3-furancarboxylic acid, 5-methyl furfural, 6-aminohexanoic acid, succinic anhydride, o-xylene, and benzaldehyde. In the infected T. molitor individuals, the mean number of G. polymorpha equaled 45 specimens per host. The groups of smaller mealworms had fewer gregarines. Positive correlation was seen between growth rates of T. molitor larvae and the intensity of invasion by gregarines. [ABSTRACT FROM AUTHOR]

Simple Summary: Due to the growing world population, the sustainability of food and feed sources with high nutritional value has become a crucial issue. In this scenario, insects can constitute a low-impact protein source with high nutritional value. The growth and nutrient composition of insects are potentially influenced by rearing conditions, particularly by the selected growth substrate. In this study, we evaluated the chemical and functional characteristics of Tenebrio molitor larvae reared on different growth substrates: a traditional wheat bran substrate and an innovative substrate consisting of wheat bran supplemented with chestnut shell, a by-product of the chestnut agro-industrial chain. The results showed that the innovative growth substrates positively influenced the insects' survival suggesting a beneficial effect on larval health. The enrichment of the growth substrate with chestnut shell modified the protein and amino acid profile of insect meals, possibly indicating a shift in their metabolism. In addition, insect meals obtained from larvae reared on chestnut-shell-enriched substrate exhibited higher antibacterial and antioxidant activity, suggesting a potential beneficial effect when included in animal feed. Our results showed positive outcomes related to the design of innovative strategies for insect rearing, enriching larvae meal with beneficial health properties in line with sustainability and One Health principles. Tenebrio molitor larvae represent a sustainable protein source for food and feed. The aim of this study was to evaluate the supplementation of chestnut shell, a by-product of the agro-industrial chain, in growth substrates for T. molitor larvae rearing. Seven-week-old larvae were reared on three different growth substrates: the control group (CTRL) was fed wheat bran, treatment group one was fed wheat bran supplemented with 12.5% w/w chestnut shell (TRT1), and treatment group two was fed wheat bran supplemented with 25% w/w chestnut shell (TRT2). Larval weight, substrate consumption, and mortality were recorded weekly. After 14 days, insect meals were produced for bromatological and colorimetric analysis, and bacterial inhibition activity assay using a microdilution method. The amino acid profile of insects was determined using quantitative nuclear magnetic resonance spectroscopy. Our results showed a lower feed conversion ratio and higher larval survival rate % in TRT2 compared to CTRL (p < 0.05). Proteins and lipids of TRT2 were higher than other groups (p < 0.05). Important differences were observed in the amino acid profile of TRT1 and TRT2 compared to CTRL (p < 0.05). TRT1 and TRT2 showed higher E. coli inhibitory activity than CTRL (p < 0.05). In conclusion, chestnut shell supplementation improved the survival and functional characteristics of larvae and likely impacted the insects' metabolism. [ABSTRACT FROM AUTHOR]

Fresh insects in the form of paste can be conveniently utilised for further food preparations and processing at both household and industrial levels. However, due to the high moisture content and particular physiochemical properties, insect paste is highly unstable and susceptible to significant quality changes during storage. The aim of this study was to evaluate the microbiological and physicochemical stability of high hydrostatic pressure (HHP) treated Tenebrio molitor paste stored at different modified atmosphere packaging (MAP) conditions. Three different MAP compositions and normal air were applied. pH, colour, lipid oxidation, fluorescence spectra and microbiological parameters were evaluated along 28 days of refrigerated storage (4 °C). HHP treatment (600 MPa, 5 min) resulted in a significant reduction in mesophilic aerobic bacteria, anaerobic bacteria and yeast and mould counts. Growth of mesophilic aerobic and anaerobic bacteria remained low for 7 days at 4 °C, regardless of the applied atmospheric conditions, while high microbial growth was observed after 14 days without any significant differences among the treatments. The number of mesophilic spores remained low throughout the entire storage period when MAP was applied, whereas high values were observed after 28 days in the samples stored in normal air. Listeria monocytogenes, Salmonella spp. and Escherichia coli were not detected in any of the samples, nor in the raw paste. Lipid oxidation was initiated by the HHP treatment and displayed an increasing trend during the storage period, although the oxidation levels were lower in the MAP without oxygen compared to the normal air packaging and in MAPs with high O2 or CO2 levels. Fluorescence spectroscopy showed high potential for rapid detection of chemical changes in insect products during processing and storage. Overall, this study showed that MAP can effectively be applied on HHP-treated insect paste to extend its storage period. Absence of oxygen has been identified as a crucial factor in achieving reduced microbial growth and ensuring high physiochemical quality of the final product. Therefore, the present research offers a valuable insight for creating new edible insect-based products within the food industry. [ABSTRACT FROM AUTHOR]

Insects are of great interest as novel sources of alternative proteins and biologically active compounds, primarily anticancer agents. Protein-rich insect larval hemolymph is a prospective candidate for pharmaceutical and food industry-related research. In this study, selected biochemical properties and cell toxicity of larval hemolymph from two mealworm species, Tenebrio molitor and Zophobas morio, were analyzed. Total proteins and carbohydrates, antioxidant capacity, and the level of lipid peroxidation were determined. Human cancer (U-87) and normometabolic (MRC-5) cells were treated with different concentrations of larval hemolymph proteins, and the effects on cell viability were assayed 24, 48, and 72 h after treatments. Z. morio hemolymph was shown to be richer in total proteins, showing a higher antioxidant capacity and lipid peroxidation level than T. molitor hemolymph, which was richer in total carbohydrates. Cytotoxicity assays showed that T. molitor and Z. morio hemolymphs differently affect the viability of U-87 and MRC-5 cells in cell type-, dose-, and time-dependent manners. Hemolymph from both species was more cytotoxic to U-87 cells than to MRC-5 cells, which was particularly prominent after 48 h. Additionally, a more potent cytotoxic effect of Z. morio hemolymph was observed on both cell lines, likely due to its higher antioxidant capacity, compared to T. molitor hemolymph. [ABSTRACT FROM AUTHOR]

Foods enriched with insects can potentially prevent several health disorders, including cardiovascular diseases, by reducing inflammation and improving antioxidant status. In this study, Tenebrio molitor and Gryllus assimilis were selected to determine the effect on the development of atherosclerosis in ApoE/LDLR−/− mice. Animals were fed AIN-93G-based diets (control) with 10% Tenebrio molitor (TM) and 10% Gryllus assimilis (GA) for 8 weeks. The nutritional value as well as antioxidant activity of selected insects were determined. The lipid profile, liver enzyme activity, and the fatty acid composition of liver and adipose tissue of model mice were evaluated. Quantitative analysis of atherosclerotic lesions in the entire aorta was performed using the en face method, and for aortic roots, the cross-section method was used. The antioxidant status of the GA cricket was significantly higher compared to the TM larvae. The results showed that the area of atherosclerosis (en face method) was not significantly different between groups. Dietary GA reduced plaque formation in the aortic root; additionally, significant differences were observed in sections at 200 and 300 µm compared to other groups. Furthermore, liver enzyme ALT activity was lower in insect-fed groups compared to the control group. The finding suggests that a diet containing edible insect GA potentially prevents atherosclerotic plaque development in the aortic root, due to its high antioxidant activity. [ABSTRACT FROM AUTHOR]

Tenebrio molitor gained recognition for its nutritional value for human and/or animal consumption, its utilization as a model species in research studies, and its ability to degrade many types of plastics. However, it is a stored-product pest infesting a wide range of commodities in storages. The impact of temperature on the development of T. molitor was evaluated, taking into account confounding effects of other covariates such as developmental stage and larval instar. The time for larval development was longer at 22.5 °C than at 25 °C, 27.5 °C, and 30 °C. Tenebrio molitor spent most of its lifetime as larva > egg, pupa, since the outcome of our model inference resulted that the estimated probability of longer duration in larvae is approximately 25.5 times higher compared to eggs and pupae, and passed through 26 instars before it became pupa. Duration of larval instars increased significantly up to L22 and then decreased until L26. Among larval instars, L22 exhibited the highest developmental duration while the lowest was recorded for L1. These findings enhance the knowledge about the biology of T. molitor, leading to precise decisions for its successful culture. [ABSTRACT FROM AUTHOR]

There is a need for alternatives or complements to synthetic fertilizers to enhance agricultural sustainability. Applying organic amendments can play a significant role in this. Insect droppings show high potential, though studies evaluating their agronomic value have only recently begun to emerge. This study compared black soldier fly (Hermetia illucens L.) and mealworm (Tenebrio molitor L.) larvae frass with another organic amendment (Nutrimais) derived from composting forestry, agro-industrial, and domestic waste. The experiment also included ammonium nitrate at two rates [the same as the organic amendments, 50 kg ha−1 nitrogen (N) (FullR), and half that rate (HalfR)] and an unfertilized control. The study spanned two growth cycles of lettuce (Lactuca sativa L.) grown in pots, followed by unfertilized oats (Avena sativa L.) to assess the residual effects of the fertilizing treatments. Mealworm larvae frass mineralized rapidly, with an apparent N recovery of 37.4% over the two lettuce growth cycles, indicating its high availability to soil heterotrophic microorganisms. The average dry matter yield (DMY) of lettuce was the highest among all treatments (12.8 and 9.8 g plant−1 in the first and second lettuce cycles), even compared to the FullR treatment (12.2 and 7.8 g plant−1), though without significant differences. Although mealworm larvae frass exhibited a high mineralization rate, the DMY cannot be attributed solely to N supply, as plants in the FullR treatment showed better N nutritional status. Mealworm larvae frass provided strong evidence of a plant biostimulant effect, not explained by the variables measured in this study. Black soldier fly larvae frass exhibited typical behavior of a moderately reactive organic amendment, while Nutrimais showed low reactivity, with a near-neutral mineralization/immobilization balance. The results suggest mealworm larvae frass is recommended for early maturing vegetable crops, whereas Nutrimais appears more suitable for perennial crops with low short-term nutrient requirements. [ABSTRACT FROM AUTHOR]

Background: Insects encounter various environmental stresses, in response to which they generate reactive oxygen species (ROS). Superoxide dismutase (SOD) is an antioxidant metalloenzyme that scavenges superoxide radicals to prevent oxidative damage. Objective: To investigate expressions of SODs under oxidative stress in Tenebrio molitor. Methods: Here, we investigated the transcriptional expression of SODs by pesticide and heavy metals in Tenebrio moltior. First, we searched an RNA-Seq database for T. molitor SOD (TmSOD) genes and identified two SOD isoforms (TmSOD1-iso1 and iso2). We examined their activities under developmental stage, tissue-specific, and various types (pesticide and heavy metal) of oxidative stress by using qPCR. Results: Our results revealed two novel forms of TmSODs. These TmSODs had a copper/zinc superoxide dismutase domain, active site, Cu2+ binding site, Zn2+ binding site, E-class dimer interface, and P-class dimer interface. TmSODs (TmSOD1-iso1 and iso2) were expressed in diverse developmental phases and tissues. Pesticides and heavy metals caused an upregulation of these TmSODs. Conclusion: Our findings suggest that the two TmSODs have different functions in T. molitor, providing insights into the detoxification ability of T. molitor. [ABSTRACT FROM AUTHOR]

Monopterus albus is one of China's renowned and superior aquaculture species, with its seedlings mainly sourced from wild capture. One of the bottlenecks in M. albus aquaculture is the high mortality rate and low feeding initiation rate from stocking wild fry to the initiation of feeding. In production, trash fish is commonly used to wean M. albus juveniles onto feeding. In this study, we introduced three other natural feeds, earthworms (EW), yellow mealworms (YMW), and fly maggots (FM), with frozen trash fish (TF) serving as the control group, to evaluate the effects of these four natural feeds on the survival rate, feeding initiation, antioxidant enzymes activity, and body composition of M. albus juveniles under recirculating water aquaculture conditions. The experiment comprised four treatments, each with three replicates. Each replicate consisted of stocking 150 M. albus juveniles weighing 10.02 ± 0.89 g in size, raised for 5 weeks. The survival rate of the YMW group was 73.33%-85.33%, which was significantly higher than that of the other three bait groups (p < 0.05). The four bait groups showed no significant differences in final body weight and specific growth rate (SGR) (p > 0.05). The EW group showed the highest final body weight, with an average SGR of 2.73, whereas the YMW group had an average SGR of 1.87. The average daily feeding amount was significantly higher in EW and YMW groups than in the other two groups (p < 0.05). The percentage of feeding amount to fish weight in the EW group reached 7.3% in the fifth week. After 5 weeks of cultivation, NO2--N content was significantly higher in the waters of the TF and EW groups than in the waters of the FM and YMW groups (p < 0.05), there was no significant difference in TAN content among the treatment groups (p > 0.05). Liver malondialdehyde content was significantly higher in the TF group than in the other bait groups (p < 0.05). GSH-Px activity was significantly higher in the EW group than in the FM group and YMW group. No significant differences in SOD and CAT activity and T-AOC were observed among the bait groups (p > 0.05). The increase in crude protein content was significantly higher in the TF group than in the FM group, but the increase in crude ash content was significantly lower in the TFgroup. In conclusion, Tenebrio molitor could potentially serve as one of the alternative feeds during the initial stages of M. albus juveniles stocking. [ABSTRACT FROM AUTHOR]

Here, a comprehensive cytogenetic analysis of three species of tenebrionid beetles: Alphitobius diaperinus, Tenebrio molitor and Zophobas morio, is presented. This paper also contains a review of the cytogenetic information for each species and adds new data. The male karyotype of both T. molitor and Z. morio is 2n = 18 + Xyp, with large heterochromatic blocks in the pericentromeric regions of all chromosomes. The male A. diaperinus karyotype is 2n = 18 + X0, also with heterochromatic pericentromeric regions in all chromosomes. The location of the nucleolar organizer regions (NORs) differs in each species: in A. diaperinus, it is located on the smallest pair of autosomes, while in T. molitor, it is on two pairs of autosomes and both sex chromosomes. In contrast, it is exclusively located on the X chromosome in Z. morio. Telomere analysis revealed that all species have TCAGG repeats in their telomeres, but lack the canonical TTAGG insect telomeric motif. In addition, a study of the distribution of satellite DNA and composition revealed that each species has a main satellite DNA family forming the pericentromeric heterochromatin. Fluorescence in situ hybridization of each of these satellites did not produce hybridization signal in the other two species, indicating a divergence in repetitive DNA composition among them. This study adds to the understanding of chromosomal organization, heterochromatin distribution and repetitive DNA dynamics in tenebrionid beetles and sheds light on their cytogenetic diversity and evolutionary significance. [ABSTRACT FROM AUTHOR]