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Many insects are obligatorily associated with and dependent on specific microbial species as essential mutualistic partners. In the host insects, such microbial mutualists are usually maintained in specialized cells or organs, called bacteriocytes or symbiotic organs. Hence, potentially exponential microbial growth cannot be realized but must be strongly constrained by spatial and resource limitations within the host cells or tissues. How such endosymbiotic bacteria grow, divide, and proliferate is important for understanding the interactions and dynamics underpinning intimate host-microbe symbiotic associations. Here we report that Blattabacterium, the ancient and essential endosymbiont of cockroaches, exhibits unexpectedly high rates of cell division (20%-58%) and, in addition, the cell division is asymmetric (average asymmetry index >1.5) when isolated from the German cockroach Blattella germanica. The asymmetric division of endosymbiont cells at high frequencies was observed irrespective of host tissues (fat bodies vs ovaries) or developmental stages (adults vs nymphs vs embryos) of B. germanica, and also observed in several different cockroach species. By contrast, such asymmetric and frequent cell division was observed neither in Buchnera, the obligatory bacterial endosymbiont of aphids, nor in Pantoea, the obligatory bacterial gut symbiont of stinkbugs. Comparative genomics of cell division-related genes uncovered that the Blattabacterium genome lacks the Min system genes that determine the cell division plane, which may be relevant to asymmetric cell division. These observations combined with comparative symbiont genomics provide insight into what processes and regulations may underpin the growth, division, and proliferation of such bacterial mutualists continuously constrained under within-host conditions. IMPORTANCE Diverse insects are dependent on specific bacterial mutualists for their survival and reproduction. Due to the long-lasting coevolutionary history, such symbiotic bacteria tend to exhibit degenerative genomes and suffer uncultivability. Because of their microbiological fastidiousness, the cell division patterns of such uncultivable symbiotic bacteria have been poorly described. Here, using fine microscopic and quantitative morphometric approaches, we report that, although bacterial cell division usually proceeds through symmetric binary fission, Blattabacterium, the ancient and essential endosymbiont of cockroaches, exhibits frequent and asymmetric cell division. Such peculiar cell division patterns were not observed with other uncultivable essential symbiotic bacteria of aphids and stinkbugs. Gene repertoire analysis revealed that the molecular machinery for regulating the bacterial cell division plane are lost in the Blattabacterium genome, suggesting the possibility that the general trend toward the reductive genome evolution of symbiotic bacteria may underpin their bizarre cytological/morphological traits. [ABSTRACT FROM AUTHOR]

Introduction: Multiple antigen environmental sources have been identified as possible causes of allergies, but few studies have evaluated changes in the sensitization profiles over time. The aim of this study was to evaluate the changes in IgE sensitization and exposure to dust mites, cats, dogs, and cockroaches over a 10-year period. Methods: During a period of 10 years among patients with asthma, rhinitis and/or atopic dermatitis, we evaluated the annual frequency of atopy to Dermatophagoides farinae, Dermatophagoides pteronyssinus, Blomia tropicalis, Canis familiaris, Felis domesticus and cockroaches (Periplaneta americana and Blatella germanica). Exposure to sources was also assessed using questionnaires (Pets) or direct counts (House dust mites and cockroaches). The association between some risk factors and the prevalence of atopy was explored. Results: A total of 6,000 records were included. Among the patients, 82% had IgE sensitization to at least one of the six allergenic sources. Sensitization to Dermatophagoides spp. was the most frequent (>78%). Exposure and sensitization in the first decade of life to Dermatophagoides spp. seem to determine the molecular spreading to other allergenic sources. Exposure to Blomia tropical increases significantly over time (year 2015; 38% vs. year 2022; 51%, p 0.03). Exposure to dogs was higher than with cats but association between atopy and exposure was stronger with cats (OR 27.4, 95% CI: 22.3–33.6, p < 0.01). Conclusion: Exposure and sensitization in the first decade of life to Dermatophagoides spp. determine the molecular spreading of IgE antibodies to other allergenic sources. Household exposure to dogs and cats seems to be important for the subsequent development of atopy. Sensitization to B. tropicalis and cockroach appears to be mostly from cross-reactivity rather than direct exposure. [ABSTRACT FROM AUTHOR]

The cockroaches have become the most common domestic insect pest of public health and epidemiological importance. Their presence raises safety concerns, especially as carriers of food-borne pathogens and foodspoilage organisms. Hence, this study aimed to document the bacteria isolated from the body surface and gut of cockroaches at Federal University Wukari, Nigeria. Using a swab bacteriological technique, investigations were carried out on the body surface and gut of cockroaches picked from sewers, kitchens, and bathrooms from student's hostels and opened fields of the institution. Nutrient and MacConkey agar were used as media. Students t-test was used to statistically compare the bacterial load recorded on samples retrieved from open field vis-à-vis the hostels. From the two sampled sites, the gut had higher colony forming unit (Cfu/ml) of (1.5 ×106±33435.80) vis-à-vis the body surface (6.9×104±13388.88). Marginally higher bacterial isolates were observed on cockroaches retrieved from the open field (25 bacterial isolates) than from students' hostels (23 bacterial isolates). In this study, Staphylococcus aureus was the most predominantly isolated bacterial species from both locations followed by Escherichia coli. Species with lower frequencies were Proteus mirabilis, Bacillus species, and Pseudomonas aeruginosa. Control and preventive strategies for cockroaches are paramount in suppressing the contamination of food by microbes associated with cockroaches. Additionally, optimum hygiene practices should be instituted in the hostels, food canteens, and clinics/hospitals of the University; and indeed, the host community to avoid the build-up of breeding sites of cockroaches which are known to carry and spread pathogenic bacteria. [ABSTRACT FROM AUTHOR]

Armophorid ciliates of family Clevelandellidae represent ecologically interesting symbionts of ecologically interesting hosts: wood-eating cockroaches of subfamily Panesthiinae unrelated to the termite/ Cryptocercus lineage. Moreover, these protists exhibit a peculiar morphology, with the posteriorization of oral structures being the most striking of their unique characters. Despite that, the family is relatively understudied, with only a handful of morphologically novel species being described since its erection more than 80 years ago. Recently, however, several clevelandellid species were described solely on the basis of molecular characters and it has been suggested that morphology should be abandoned in favour of purely molecular taxonomy. In our study we report on the diversity of Clevelandellidae from the widest host spectrum assessed so far, characterize a majority of previously described Clevelandellidae species, and describe six new Clevelandella species. By applying an integrative taxonomical approach, using molecular and modern morphological methods, we demonstrate the pitfalls of a purely molecular approach and show that morphology still has its place in the taxonomy of Clevelandellidae. Moreover, thanks to a combination of observations of in vivo cells, protargol preparations, and scanning electron microscopy (used for the first time in Clevelandellidae), we were able to clarify morphological uncertainties of previous works and discuss various morphological peculiarities of Clevelandellidae. [ABSTRACT FROM AUTHOR]

This paper presents an original method for noninvasive recording of electroretinogram from both compound eyes of insects. The method was found to be highly reliable and reproducible. The photovoltaic effect, which distorts response amplitude and shape, was eliminated by using a gold recording electrode. The data obtained using this method showed that the magnitudes of the responses of the eyes in pearl mutant cockroaches, which lack screening pigment, to light stimuli were approximately four times greater than those of wild-type insects. The time to peak response decreased with increases in stimulus light intensity for shortwave and long-wave stimuli. Pearl cockroaches reached maximum responses faster than wild-type cockroaches. Results of covariance analysis indicated that these differences could not be explained completely in terms of an increase in the number of photons reaching photoreceptor membranes. This suggests that there are additional differences in the physiology of the compound eye between mutant and wild-type individuals. The positive deflection of the potential after the end of light stimulation depended on light intensity and was a reflection of receptor cell hyperpolarization. [ABSTRACT FROM AUTHOR]

BACKGROUND: Cockroaches are widely acknowledged as significant vectors of pathogenic microorganisms. The Periplaneta fuliginosa densovirus (PfDNV) infects the smoky‐brown cockroach P. fuliginosa and causes host mortality, which identifies the PfDNV as a species‐specific and environmentally friendly biopesticide. However, although the biochemical characterization of PfDNV has been extensively studied, the immune response against PfDNV remains largely unclear. RESULTS: Here, we investigated the replication of PfDNV and its associated pathological phenotype in the foregut and hindgut. Consequently, we dissected and performed transcriptome sequencing on the foregut, midgut, and hindgut separately. We revealed the up‐regulation of immune response signaling pathway c‐Jun N‐terminal kinase (JNK) and apoptosis in response to viral infection. Furthermore, knockdown of the JNK upstream gene Ben resulted in a decrease in virus titer and delayed host mortality. CONCLUSION: Taken together, our findings provide evidence that the Ben‐JNK signaling plays a crucial role in PfDNV infection, leading to excessive apoptosis in intestinal tissues and ultimately resulting in the death of the host. Our results indicated that the host response to PfDNV fosters viral infection, thereby increasing host lethality. This underscores the potential of PfDNV as a viable, environmentally friendly biopesticide. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Abstract Background Cockroaches can pose a significant health risk in hospital environments because they may serve as reservoirs and vectors for nosocomial pathogens. Cockroaches harbor epidemiologically significant extended spectrum and metalo beta lactamase producing Gram negative bacterial pathogens, which complicate nosocomial infections. Objectives The main aim of this study is to determine aetiology and phenotypic extended spectrum and metalo beta lactamase producing Gram negative bacteria pathogens from cockroaches collected in hospitals. Methods A cross-sectional study was employed from February to May 2022 to determine the antibiotic resistance producing bacterial isolates from cockroaches by giving special emphasis to metalo beta lactamase and extended spectrum beta lactamase production from different wards of WSUCSH. Cockroaches were collected with hands wearing sterile gloves. External homogenate was prepared and incubated microbiologically by using different culture media and differentiated biochemically. Antimicrobial susceptibility testing was performed by disk diffusion method. ESBL production was conducted using double disc synergy method and double disk method was used to detect MBL enzyme detection. Descriptive statistics was used to determine prevalence and percentage. Result Out of 245 cockroaches, 108 Gram negative bacteria were isolated. K. pneumoniae 29(26.9%) was the most predominant bacteria and Enetrobacter spp. 8(7.4%), was the least. All, K. pneumoniae, P. mirabilis, and Enterobacter isolates were pan-resistant to Ampicillin. P.aeruginosa and P.mirabilis antibiotics showed ≥ 80% resistant for amoxicillin/clavulanic acid antibiotics. Cefotaxime, ceftazidime, ceftriaxone and imipenem showed relative efficacy compared with other antibiotics. Out of 78 amoxicillin-clavulanic acid resistant isolates, 42(34.7%) were ESBL producers. ESBL production is more depicted by P. aeruginosa, A. baumannii, K. pneumoniae and E. coli. The overall prevalence of MBL production is 29(23.1%). K. pneumoniae P. aeruginosa, E.coli, A. baumannii, Enterobacter spp and K.oxytoca revealed MBL production. Conclusion The overall prevalence of ESBL and MBL producing nosocomial agents from hospital cockroaches was 34.7% and 23.1% respectively. P.aeruginosa, A.baumannii, K.pneumoniae and E.coli showed pronounced ESBL production. All bacterial isolates except P. mirabilis and C. freundii showed MBL production. The needed to evaluate our antibiotic stewardship program and antibiotic resistance detection for treatment is mandatory. The impact of cockroach as a source of AMR should be sought.

Background: Cockroaches can pose a significant health risk in hospital environments because they may serve as reservoirs and vectors for nosocomial pathogens. Cockroaches harbor epidemiologically significant extended spectrum and metalo beta lactamase producing Gram negative bacterial pathogens, which complicate nosocomial infections. Objectives: The main aim of this study is to determine aetiology and phenotypic extended spectrum and metalo beta lactamase producing Gram negative bacteria pathogens from cockroaches collected in hospitals. Methods: A cross-sectional study was employed from February to May 2022 to determine the antibiotic resistance producing bacterial isolates from cockroaches by giving special emphasis to metalo beta lactamase and extended spectrum beta lactamase production from different wards of WSUCSH. Cockroaches were collected with hands wearing sterile gloves. External homogenate was prepared and incubated microbiologically by using different culture media and differentiated biochemically. Antimicrobial susceptibility testing was performed by disk diffusion method. ESBL production was conducted using double disc synergy method and double disk method was used to detect MBL enzyme detection. Descriptive statistics was used to determine prevalence and percentage. Result: Out of 245 cockroaches, 108 Gram negative bacteria were isolated. K. pneumoniae 29(26.9%) was the most predominant bacteria and Enetrobacter spp. 8(7.4%), was the least. All, K. pneumoniae, P. mirabilis, and Enterobacter isolates were pan-resistant to Ampicillin. P.aeruginosa and P.mirabilis antibiotics showed ≥ 80% resistant for amoxicillin/clavulanic acid antibiotics. Cefotaxime, ceftazidime, ceftriaxone and imipenem showed relative efficacy compared with other antibiotics. Out of 78 amoxicillin-clavulanic acid resistant isolates, 42(34.7%) were ESBL producers. ESBL production is more depicted by P. aeruginosa, A. baumannii, K. pneumoniae and E. coli. The overall prevalence of MBL production is 29(23.1%). K. pneumoniae P. aeruginosa, E.coli, A. baumannii, Enterobacter spp and K.oxytoca revealed MBL production. Conclusion: The overall prevalence of ESBL and MBL producing nosocomial agents from hospital cockroaches was 34.7% and 23.1% respectively. P.aeruginosa, A.baumannii, K.pneumoniae and E.coli showed pronounced ESBL production. All bacterial isolates except P. mirabilis and C. freundii showed MBL production. The needed to evaluate our antibiotic stewardship program and antibiotic resistance detection for treatment is mandatory. The impact of cockroach as a source of AMR should be sought. [ABSTRACT FROM AUTHOR]

Volatile sex pheromones are vital for sexual communication between males and females. Females of the American cockroach, Periplaneta americana, produce and emit two sex pheromone components, periplanone-A (PA) and periplanone-B (PB). Although PB is the major sex attractant and can attract males, how it interacts with PA in regulating sexual behaviors is still unknown. In this study, we found that in male cockroaches, PA counteracted PB attraction. We identified two odorant receptors (ORs), OR53 and OR100, as PB/PA and PA receptors, respectively. OR53 and OR100 were predominantly expressed in the antennae of sexually mature males, and their expression levels were regulated by the sex differentiation pathway and nutrition-responsive signals. Cellular localization of OR53 and OR100 in male antennae further revealed that two types of sensilla coordinate a complex two-pheromone-two-receptor pathway in regulating cockroach sexual behaviors. These findings indicate distinct functions of the two sex pheromone components, identify their receptors and possible regulatory mechanisms underlying the male-specific and age-dependent sexual behaviors, and can guide novel strategies for pest management. [ABSTRACT FROM AUTHOR]

Introduction: Sensitivity to indoor allergens increases the risks of asthma and the emergence of allergic diseases. Indoor allergens include house dust mite (HDM), pet dander, cockroach (CR), and molds. We investigated how CR sensitivity was affected during the pandemic period. Methods: This study included patients aged ≥18 years who visited the allergy unit of our clinic between March 2018 and March 2022 and who underwent skin prick tests (SPTs) for aeroallergens. Patients were divided into two groups: those of the prepandemic and pandemic periods, depending on the visit dates. Results: In all, 7,687 patients were recruited; 5,074 individuals with negative SPT results were excluded. Among the 2,613 atopic patients, CR sensitivity was detected in 278 (10.6%). The prevalence of CR sensitivity was significantly higher in the pandemic group than in the prepandemic group (12% vs. 8.6%; p < 0.05). The frequency of asthma was higher in patients with CR sensitivity than in others (33.1% vs. 26%, p = 0.011). In addition, individuals with CR sensitivity were older than others (p = 0.001). CR sensitivity was more common in males than in females (44.2% vs. 37.7%, p = 0.034). Moreover, dog and HDM sensitivities were more common in individuals with CR sensitivity than in others (p = 0.004, p < 0.001, respectively). Conclusion: This study reveals an increased sensitivity to CR during the pandemic and establishes an association between such sensitivity and the frequency of asthma. Variability in terms of CR sensitivity across different countries is emphasized. In addition, HDM and dog sensitivities were more common in individuals with CR sensitivity. [ABSTRACT FROM AUTHOR]

The parasitoid wasp Ampulex compressa hunts down its host, the American cockroach (Periplaneta americana), and envenomates its brain to make it a behaviorally compliant food supply for its offspring. The primary target of the wasp sting is a locomotory command center called the central complex (CX). In the present study, we employ, for the first time, chronic recordings of patterned cockroach CX activity in real time as the brain is infused with wasp venom. CX envenomation is followed by sequential changes in the pattern of neuronal firing that can be divided into three distinct temporal phases during the 2 h interval after venom injection: (1) reduction in neuronal activity for roughly 10 min immediately after venom injection; (2) rebound of activity lasting up to 25 min; (3) reduction of ongoing activity for up to 2 h. Long-term reduction of CX activity after venom injection is accompanied by decreased activity of both descending interneurons projecting to thoracic locomotory circuitry (DINs) and motor output. Thus, in this study, we provide a plausible chain of events starting in the CX that leads to decreased host locomotion following brain envenomation. We propose that these events account for the onset and maintenance of the prolonged hypokinetic state observed in stung cockroaches.

Two new species of Eupolyphaga (E. bicolor Han, Che & Wang, sp. nov. and E. nigra Han, Che & Wang, sp. nov.) and six new species of Pseudoeupolyphaga (P. flava Han, Che & Wang, sp. nov., P. deficiens Han, Che & Wang, sp. nov., P. magna Han, Che & Wang, sp. nov., P. longiseta Han, Che & Wang, sp. nov., P. latizona Han, Che & Wang, sp. nov., and P. baimaensis Han, Che & Wang, sp. nov.) are described and illustrated. The female external genitalia and spermathecae of these two genera are reported and the role of these characters in species delimitation is discussed. [ABSTRACT FROM AUTHOR]

Introduction: German cockroach (GCr) aeroallergens are associated with allergic rhinitis and asthma. Vitellogenin (Vg) and vitellin (Vn) are abundant proteins in GCr blood and eggs (including egg cases), respectively, and are possible high molecular mass allergens. Prior efforts to purify Vg/Vn yielded amounts too small for subsequent studies. In this study, we report the affinity purification of Vg/Vn from whole-body defatted GCr powder and determination of the binding of Vg/Vn to anti-GCr IgE. Method: New Zealand white rabbits were immunized with pure Vg/Vn in Freund's adjuvant, and IgG was purified from the rabbit sera and conjugated to cyanogen bromide (CNBr)-activated Sepharose. Aqueous extracts from GCr powder were passed over the column. After extensive washing, putative Vg/Vn was eluted in low-pH buffer, neutralized, and analyzed by SDS-PAGE and liquid chromatography high-resolution mass spectrometry (LC-HRMS). IgE binding of Vg/Vn was evaluated by inhibition of IgE binding to GCr-ImmunoCAP(I6) in sera from 10 GCr-allergic individuals. In addition, Vg/Vn was biotinylated and bound to ImmunoCAP-streptavidin, and direct IgE antibody binding to the immobilized Vg/Vn was determined in sera from 26 GCr-allergic individuals. Results: Vg/Vn isolated by affinity chromatography was 91% pure by LC-HRMS; contaminants included Bla g 3 (0.9%), human keratin (6%), and rabbit IgG. Vg/Vn inhibited IgE binding to GCr-ImmunoCAP(I6) in 8 of 10 sera. In direct-binding experiments, 21/26 (80%) sera had anti-Vg/Vn IgE at>0.10 kUA/L, while 11/26 (42%) sera were>0.35 kUA/L. Conclusions: We affinity-purified Vg/Vn and demonstrated that Vg/Vn-specific IgE antibody is a major component of GCr-specific IgE. [ABSTRACT FROM AUTHOR]

Background and Aim: The ability of cockroaches to transmit pathogenic agents to food makes them a threat to the country's food security in terms of use in war and biological terror. In this research, the identification of cockroaches (Blattodea), their geographic distribution, and establishment potential in date warehouses of six important date-growing provinces of Iran, including Kerman, Fars, Khuzestan, Sistan and Baluchistan, Bushehr, and Hormozgan, were carried out to their risk predict. Methods: The statistical method of factor analysis was used to investigate the variance between several dependent variables based on their description in terms of a few latent variables (factors) effective on the type of population distribution. The cluster analysis was performed using a hierarchical method and its accuracy was evaluated using linear detection techniques and a generalization of Fisher's linear discriminator. Results: Three species of cockroaches, including the American cockroach Periplaneta americana, the eastern cockroach Blatta orientalis, and the German cockroach Blattella germanica, are active in Iran's date-producing areas. The highest distribution of these cockroaches was in (Kerman, Fars, and Bushehr), (Kerman and Sistan and Baluchistan), (Khuzestan and Sistan and Baluchistan), (Khuzestan and Sistan and Baluchistan), Bushehr and Fars, respectively. The highest relative establishment rate was found in the provinces of Sistan and Baluchistan, Hormozgan, and Khuzestan. The largest unexploited habitat niche was in Hormozgan province, related to the German cockroach. The unanticipated outbreak chance of cockroaches in the warehouses of that province increases with the index of the unexploited habitat niche in that province. Conclusion: Early detection to prevent the spread of the biological agent is a passive defense against the biological threat. The results of this research are essential in analyzing the risk of cockroaches and determining the hazards caused by them. [ABSTRACT FROM AUTHOR]

We examined new Allacta materials from Yunnan and Hainan Province, China, and discovered new species using both morphological and molecular species delimitation (ABGD) methods. Five new species are described: A. bifolium Li & Wang, sp. nov., A. hemiptera Li & Wang, sp. nov., A. lunulara Li & Wang, sp. nov., A. redacta Li & Wang, sp. nov., and A. unicaudata Li & Wang, sp. nov. All five species are placed under the hamifera species group. An updated key and checklist of Allacta species from China are provided. [ABSTRACT FROM AUTHOR]

Simple Summary: Acetamiprid, which is a neonicotinoid, is a cyano-substituted insecticide. It is commonly used due to its rapid insecticidal activity. Acetamiprid has been described as a partial agonist of nicotinic acetylcholine receptors expressed on the thoracic and dorsal neurons of the American cockroach. However, previous electrophysiological studies have demonstrated that not all neonicotinoids display the same modes of action on insects. In this study, we analysed the effect of acetamiprid on the locomotor activity of the American cockroach and compared our results with previously published data for thiamethoxam and clothianidin, which are nitro-substituted neonicotinoid insecticides. We demonstrated that the three neonicotinoids had different effects on the locomotor activity. Overall, these data add to the understanding of the mode of action of neonicotinoid insecticides. Toxicological studies have shown that the American cockroach Periplaneta americana (Linnaeus) is a classical model for studying the mode of action of commonly used insecticides. In a previous study, we demonstrated that thiamethoxam and clothianidin decreased locomotor activity in an open-field-like apparatus. Here, we tested the effect of the neonicotinoid acetamiprid when applied orally, topically, or injected into the haemolymph. We found that acetamiprid was also able to impair locomotor activity in the open-field-like apparatus. When treated with acetamiprid, a strong alteration in locomotor activity was observed 1 h, 24 h, and 48 h after haemolymph and topical applications. Oral application induced an impairment of locomotor activity at 24 h and 48 h. A comparison of the present data with our previously published results showed that neonicotinoids were more active when injected into the haemolymph compared to oral and topical applications. These findings increased our understanding of the effect of neonicotinoid insecticides on insect locomotor activity, and demonstrated that the cyano-substituted neonicotinoid, acetamiprid, was able to alter cockroach locomotor activity. [ABSTRACT FROM AUTHOR]

Simple Summary: Low food availability imposes an energy tradeoff between metabolism for somatic maintenance and growth in animals. It has been hypothesized that energy allocation strategies under food restriction depend on whether the length of an animal's potential development stage is longer or shorter than that of the food scarcity period, i.e., long development stages prioritize metabolism over growth, and short ones are the opposite. This hypothesis was partially proven true in hornworms (larvae of Manduca sexta), a holometabolous insect species with a short development stage of ~4 weeks, but it is not clear if it holds for other insect species with long development. To further test this hypothesis, here, we use orange head cockroaches (Eublaberus posticus), which usually need several months to reach adulthood. We found that hornworms and cockroaches, two species with different life histories, have opposite energy allocation strategies under food restrictions, which may affect their health maintenance and lifespan. Animals with different life histories budget their intake energy differently when food availability is low. It has been shown previously that hornworm (larva of Manduca sexta), a holometabolous insect species with a short development stage, prioritizes growth at the price of metabolism under food restriction, but it is unclear how hemimetabolous insect species with a relatively long development period budget their intake energy under food scarcity. Here, we use orange head cockroaches (Eublaberus posticus) to investigate this question. We found that for both species under food restriction, rates of metabolism and growth were suppressed, but the degree of reduction was more severe in growth than that of metabolism for cockroaches. Under both free-feeding and food restriction conditions, hornworms allocated a larger fraction of assimilated energy to growth than to metabolism, and cockroaches were the opposite. More importantly, when food availability was low, the fraction of assimilated energy allocated to growth was reduced by 120% in cockroaches, and the energy from growth was channeled to compensate for the reduction in metabolism; but, the fraction of assimilated energy allocated to growth was only reduced by 14% in hornworms. These results suggest that, compared to hornworms, cockroaches prioritize metabolism over growth. [ABSTRACT FROM AUTHOR]

The transcription factor Ftz‐f1 has multiple functions in insect development in a spatial‐temporal line. One of these roles is in the insect ovaries, specifically in the regulation of steroidogenic enzymes production. We studied the function of F in Blattella germanica oogenesis, as it shows two moments of high expression in ovaries: before the imaginal moult, and just before ovulation in the adult. Injecting dsftz‐f1 into adult females, either just after the imaginal moult or just prior to choriogenesis, prevented oviposition, with differences between the two approaches. In 3‐day‐old adult females treated with dsftz‐f1 just after the emergence, the expression of ftz‐f1 was not modified, but the steroidogenic genes increased their expression. ftz‐f1 transcript levels in the ovaries of 5‐day‐old dsftz‐f1‐treated females were significantly depleted, and the expression levels of the same steroidogenic genes began to decrease. These results suggest that Ftz‐f1 regulates the expression of steroidogenic genes in B. germanica, with phm possibly being a key target. Ftz‐f1 has a different temporal function in the cytoskeleton of follicular cells of the basal ovarian follicles. Early in the gonadotrophic cycle, Ftz‐f1 promotes the expression of genes related to the cytoskeleton and muscle proteins, while at the end of the cycle it maintains the expression levels of these genes, thus ensuring correct ovulation. [ABSTRACT FROM AUTHOR]

Background: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection causes a spectrum of clinical outcomes that may be complicated by severe asthma. Antiviral immunity is often compromised in patients with asthma; however, whether this is true for SARS-CoV-2 immunity and children is unknown. Objective: We aimed to evaluate SARS-CoV-2 immunity in children with asthma on the basis of infection or vaccination history and compared to respiratory syncytial viral or allergen (eg, cockroach, dust mite)-specific immunity. Methods: Fifty-three children from an urban asthma study were evaluated for medical history, lung function, and virus- or allergen-specific immunity using antibody or T-cell assays. Results: Polyclonal antibody responses to spike were observed in most children from infection and/or vaccination history. Children with atopic asthma or high allergen-specific IgE, particularly to dust mites, exhibited reduced seroconversion, antibody magnitude, and SARS-CoV-2 virus neutralization after SARS-CoV-2 infection or vaccination. TH1 responses to SARS-CoV-2 and respiratory syncytial virus correlated with antigen-respective IgG. Cockroach-specific T-cell activation as well as IL-17A and IL-21 cytokines negatively correlated with SARS-CoV-2 antibodies and effector functions, distinct from total and dust mite IgE. Allergen-specific IgE and lack of vaccination were associated with recent health care utilization. Reduced lung function (forced expiratory volume in 1 second ≤ 80%) was independently associated with (SARS-CoV-2) peptide-induced cytokines, including IL-31, whereas poor asthma control was associated with cockroach-specific cytokine responses. Conclusion: Mechanisms underpinning atopic and nonatopic asthma may complicate the development of memory to SARS-CoV-2 infection or vaccination and lead to a higher risk of repeated infection in these children.

The article is devoted to an overview of entomological imagery (spiders, ants, cockroaches, flies, etc.) in Dostoevsky’s literary and journalistic texts. The author focuses on the difference between the autological and metalogical (comparison, metaphor, symbol) use of images of insects and traces their frequency and artistic specifics in different periods of the writer’s work. The sharp increase in the number of entomological images since 1860s is related to the formation of a new artistic anthropology in Dostoevsky based on his convict experience. Special attention is paid in the article to the entomological image of bugs, which has not attracted large attention from the researchers of the writer’s artistic world.

The East–West encounter in the twenty-first century is a major theme in the works of contemporary Anglophone Arab diasporic writers. However, unlike some Arab intellectuals and writers of the previous centuries whose accounts hyperbolically praised Western lifestyles and cultures, twenty-first-century Anglophone Arab diasporic writers draw a different image of the Occident. We argue that their texts tend to restructure Arab people’s inherited glamorised image of the ‘West’ by depicting the difficulties that Arab immigrants and refugees face there. Hence, the aim of this paper is to explore the representation of the Occident in Lebanese-Canadian novelist Rawi Hage’s Cockroach (2008) and Moroccan-American novelist Laila Lalami’s The Other Americans (2021). We conclude that the selected novels, as well as other contemporary Anglophone Arab diasporic texts, can provide an insight into the importance of Occidentalism as a mechanism through which Occidentalist literature sheds light on the unconceived matters that Arabs, whether immigrants or living in the Arab world, are oblivious to and reminds the ‘West’ of the struggles that Arab immigrants/refugees encounter while living in Western societies. [ABSTRACT FROM AUTHOR]

Simple Summary: Invertebrate welfare is gaining attention, especially with the rise of insect farming for sustainable food production. Traditional individual welfare monitoring is impractical for large groups, especially when individual identification is difficult. This study adapts the Animal Welfare Assessment Grid (AWAG) for group-level assessments and successfully applies it to a captive group of male Gromphadorhina oblongonota. This modified AWAG evaluates welfare based on 12 factors tracked over time, revealing environmental and social factors' impact on G. oblongonota welfare. These findings guide practical improvements in care and offer an efficient method to assess invertebrate welfare at the group level. The welfare of invertebrates under human care is of growing concern, particularly with the increasing interest in insect farming as an environmentally sustainable means of producing food. Additionally, individual welfare monitoring systems can be time-consuming and impractical for larger groups, particularly when individual animals are difficult to identify. It is, therefore, imperative to develop a validated system for monitoring terrestrial invertebrate welfare at a group level. The Animal Welfare Assessment Grid (AWAG) is an objective welfare-monitoring tool that has been approved for use with a wide range of species. This study modified the AWAG for large group-level welfare assessments and successfully trialled it on a terrestrial invertebrate species, a group of captive male Gromphadorhina oblongonota. The modified template evaluated the group's welfare by scoring changes to 12 factors that could be tracked over time. The results highlight that the welfare of G. oblongonota is likely to be influenced by environmental and social factors, and inform practical improvements in G. oblongonota care that will result in improved welfare. The findings also demonstrate an efficient way to assess the welfare of invertebrates at the group level, and given the recent UK legislation (Animal Welfare (Sentience) Bill, 2022) plus the emerging interest in invertebrate farming, our findings hold timely significance. [ABSTRACT FROM AUTHOR]

Among animals defined as "pests", cockroaches and rodents (mouse and rat) represent the most common cause of airway allergic sensitization and bronchial asthma worldwide. Their frequency of sensitization has been widely assessed in US and other countries but poorly in Western Europe. This narrative review aims to provide a synthesis of data resulting in MEDLINE concerning allergic sensitization/asthma to pests as well as their related environmental/social risk factors, specifically in the European area. We performed a literature research in MEDLINE for clinical trials, randomized controlled trials, systematic reviews and meta-analyses. We selected studies to the following key words: allergic sensitization, allergic rhinitis, bronchial asthma, cockroach, hypersensitivity, integrated pest management, material hardship, medication compliance, mouse, pest, poverty, rat, rodents. Current evidence indicates that residence in poor and urban areas, exposure to outdoor/indoor pollutants and tobacco smoke, poverty, material hardship, poor-quality housing, differences in health care quality, medication compliance, health care access contribute to increased pest-related allergic sensitization and asthma morbidity. Further research should be done on many aspects of pest allergy such as a better characterization of allergens and epidemiological aspects. Relevant social actions should be carried out against poverty, healthcare disparities, psycho-social stress, poor compliance to therapy, with economic contributions to improve private and public living environments. Allergic sensitization to pests and pest-allergic respiratory diseases like asthma are "paradoxical" conditions, as they typically affect the poorest communities but can only be corrected by high-cost (diagnostic and preventive) interventions. We hope that progress can be made in this direction in the future. [ABSTRACT FROM AUTHOR]

While cockroaches are commonly exhibited in zoos and museums, studied in re- search laboratories, and even kept as pets, scientifically based guidelines for their euthanasia are lacking. This study assessed euthanasia techniques in four species of cockroaches (Dubia (Blaptica dubia), red runner (Shelfordella lateralis), Madagascar hissing (Gromphadorhina portentosa), and giant cave (Blaberus giganteus)). In an initial pilot study, two hundred fifty adult Dubia cockroaches were exposed in groups of ten to a cotton ball soaked with 2 mL of isoflurane in a 1 L air-tight chamber. Thirty minutes beyond loss of any individual movement, groups were exposed to one of the following secondary treatments: freezing at -18 °C or -80 °C from 0.25 to 24 hours; immersion in 10% neutral buffered formalin, 70% isopropyl alcohol, or reverse osmosis water for 0.25 or 0.5 hours; or intracoelomic injection of potassium chloride (456 mEq/kg) or pentobarbital-based euthanasia solution (3.9 g/kg). A control group remained in the air-tight isoflurane chamber for 24 hours. Following all treatments, cockroaches were monitored for an additional 24 hours for spontaneous movement. Irreversible loss of movement was considered synonymous with irreversible loss of consciousness (death). Across all species, isoflurane anesthesia followed by either 70% isopropyl alcohol immersion for 0.25 or 0.5 hours or isoflurane exposure for 24 hours resulted in euthanasia in 100% of cockroaches. This study is the first evaluation of American Veterinary Medical Association-recommended euthanasia protocols in cockroaches. [ABSTRACT FROM AUTHOR]

While cockroaches are commonly exhibited in zoos and museums, studied in research laboratories, and even kept as pets, scientifically based guidelines for their euthanasia are lacking. This study assessed euthanasia techniques in four species of cockroaches (Dubia (Blaptica dubia), red runner (Shelfordella lateralis), Madagascar hissing (Gromphadorhina portentosa), and giant cave (Blaberus giganteus)). In an initial pilot study, two hundred fifty adult Dubia cockroaches were exposed in groups of ten to a cotton ball soaked with 2 mL of isoflurane in a 1 L air-tight chamber. Thirty minutes beyond loss of any individual movement, groups were exposed to one of the following secondary treatments: freezing at −18 °C or −80 °C from 0.25 to 24 hours; immersion in 10% neutral buffered formalin, 70% isopropyl alcohol, or reverse osmosis water for 0.25 or 0.5 hours; or intracoelomic injection of potassium chloride (456 mEq/kg) or pentobarbital-based euthanasia solution (3.9 g/kg). A control group remained in the air-tight isoflurane chamber for 24 hours. Following all treatments, cockroaches were monitored for an additional 24 hours for spontaneous movement. Irreversible loss of movement was considered synonymous with irreversible loss of consciousness (death). Across all species, isoflurane anesthesia followed by either 70% isopropyl alcohol immersion for 0.25 or 0.5 hours or isoflurane exposure for 24 hours resulted in euthanasia in 100% of cockroaches. This study is the first evaluation of American Veterinary Medical Association-recommended euthanasia protocols in cockroaches.

ABSTRACT When Salmonella Typhimurium is ingested by German cockroaches, the bacteria replicate in the gut and persist for at least 7 d, enabling transmission in the feces. However, the mechanisms that facilitate survival and persistence in the cockroach gut remain poorly detailed. We previously reported the formation of biofilm-like aggregate populations of S. Typhimurium in the gut of cockroaches upon ingestion. We also reported that deletion of the type-1 fimbrial subunit of S. Typhimurium, fimA, leads to a reduced bacterial load in the cockroach gut. Here, we link these observations and provide further insight into the mechanism and function of S. Typhimurium aggregation in the gut of the cockroach. We show that S. Typhimurium but not Escherichia coli forms aggregated populations in the cockroach gut, and that aggregate formation requires fimA but not the biofilm formation-related genes csgA and csgD. Furthermore, we show that S. Typhimurium aggregates are formed using small granular deposits present in the cockroach gut, which exhibit properties consistent with melanin, as substrates. These melanin deposits are prevalent in the guts of both immature and adult cockroaches from laboratory colonies and are correlated with increased gut bacterial density while being entirely absent in gnotobiotic cockroaches reared without exposure to environmental bacteria, indicating they are induced as a response to the gut microbiota. When cockroaches lacking melanin deposits in the gut are fed S. Typhimurium, they exhibit lower rates of infection than those harboring melanin deposits, demonstrating that microbiota-induced melanin deposits enhance infection of the gut of the vector. IMPORTANCE Cockroaches, including the German cockroach (Blattella germanica), can be both mechanical and biological vectors of pathogenic bacteria. Together, our data reveal a novel mechanism by which S. Typhimurium interacts with the cockroach gut and its microbiota that promotes infection of the vector. These findings exemplify the emerging but underappreciated complexity of the relationship between cockroaches and S. Typhimurium.

The Blattodea species Nyctibora tetrasticta Hebard, 1922 was previously known only from Sinaloa, Mexico at low elevations in tropical vegetation. It is here documented considerably further north in Sonora, Mexico, at much higher elevations and in a variety of habitats. [ABSTRACT FROM AUTHOR]

Cockroaches are used in a novel technology called blatticomposting to turn agricultural waste into compost. In a country like India, recycling organic waste is not only vital for the environment, but it is also economically necessary. The composition of the nutrients in the blatticompost and vermicompost at 90 days after filling (DAF) showed significantly higher nitrogen content in partially decomposed farm waste + cockroach (3.16%), higher phosphorous content in partially decomposed farm waste + earthworm (1.81%), higher potassium content in partially decomposed kitchen waste + cockroach (1.042%), the calcium and magnesium content were highest in farm waste + earthworm (5.37 and 3.23%, respectively) and higher sulphur content in farm waste + cockroach (2.04%). At 90 DAF higher zinc content was recorded in partially decomposed farm waste + earthworm (335.395 mg/kg). Higher copper content was recorded in kitchen waste + earthworm (241.29 mg/kg). Higher manganese content was in partially decomposed farm waste + earthworm (1438.57 mg/kg). Farm waste and Kitchen waste provided to earthworm has more nutrient concentration than others and are found less in comparison with earthworms. [ABSTRACT FROM AUTHOR]

Through a selection of literary texts featuring cockroaches in the wake of Franz Kafka's Gregor Samsa in Metamorphosis (1915): Clarice Lispector's A paixão segundo G.H. (1964; The Passion According to G.H., 1988), Marc Estrin's Insect Dreams: The Half-Life of Gregor Samsa (2002), Scholastique Mukasonga's Inyenzi ou les Cafards (2006; Cockroaches, 2016), and Rawi Hage's Cockroach (2008), this article shows how these authors politicize the cockroach as bestia sacra between trauma and resilience. These literary works are exemplary in demonstrating how Anthropocene fiction resists and destabilizes biopolitically charged species metaphors with their dehumanizing agency. How do these authors, in writing beyond Kafka's doomed human cockroach, liberate the species blattodae from its aura of dehumanization and draw on the resilience of this ancient species in the face of adversity and as a model for human agency?. [ABSTRACT FROM AUTHOR]

The major lineages of winged insects originated in the Carboniferous and most extant families stemmed 150 Ma later. Until now, no family from the Carboniferous was represented by a living species or by amber fossils, leaving a significant gap in our knowledge of early insects. Here, we report new phyloblattid cockroaches, previously known mainly from the Carboniferous, including an amber fossil with outstanding 3D preservation from around 100 Ma. They represent the longest-lasting cockroach lineage and offer an unprecedented window into the Palaeozoic evolution. Specimens from Cretaceous amber and from Permian sediments represent a new genus, revealing a singular example of persistent morphology among the fast-evolving cockroaches. Together with two new taxa from the intertrappean sediments of Russia, these confirm that this family survived the Permo-Triassic extinction and persisted 213 Ma, longer than any known (Carboniferous) insect family. The new fossils share characters with the two main lineages of living cockroaches, as well as mantises and termites, thus clarifying their divergence from Phyloblattidae or direcly descendant Liberiblattinidae. [ABSTRACT FROM AUTHOR]

German cockroaches (Blattella germanica) can be both mechanical and biological (amplifying) vectors of enteric pathogens, including Salmonella enterica serovar Typhimurium (S. Typhimurium), which they acquire by feeding upon contaminated substances. Blattella germanica is also a gregarious species that shelters in groups and partakes in unique feeding behaviors such as conspecific coprophagy, necrophagy, and emetophagy. These properties create an interphase for potential horizontal transmission of pathogens among cockroach populations through the fecal‐oral route, which could in turn enhance transmission to humans and other animals. Here, we performed a series of experiments to determine: (1) whether horizontal transmission of S. Typhimurium infection takes place in B. germanica, (2) the prevalence of the phenomenon, and (3) the route(s) through which it may occur. We reveal that true horizontal transmission of S. Typhimurium occurs among B. germanica. That is, uninfected cockroaches acquire infection of the gut when co‐housed with orally infected conspecifics, albeit at low frequency. Furthermore, we provide definitive evidence that coprophagy and necrophagy are routes of transmission but could not exclude sharing of food or water as contributing routes. On the contrary, transmission by emetophagy appears less likely as oral regurgitates from infected cockroaches contained S. Typhimurium for less than one day after ingesting the bacteria. Together, our data enhance current understanding of the ecology of vector‐borne S. Typhimurium transmission by cockroaches, implicating conspecific horizontal transmission as a phenomenon that contributes to maintaining infected cockroach populations independently of contact with primary sources of the pathogen. Although the relative importance of horizontal transmission of pathogens in cockroaches in the field remains to be determined, these results also highlight the important role that food and water sources in the local environment may play in cockroach‐borne pathogen transmission and emphasize the importance of sanitation for not only abating infestations but also mitigating pathogen transmission. [ABSTRACT FROM AUTHOR]

The initial representation of the instantaneous temporal information about food odor concentration in the primary olfactory center, the antennal lobe, was examined by simultaneously recording the activity of antagonistic ON and OFF neurons with 4-channel tetrodes. During presentation of pulse-like concentration changes, ON neurons encode the rapid concentration increase at pulse onset and the pulse duration, and OFF neurons the rapid concentration decrease at pulse offset and the duration of the pulse interval. A group of ON neurons establish a concentration-invariant representation of odor pulses. The responses of ON and OFF neurons to oscillating changes in odor concentration are determined by the rate of change in dependence on the duration of the oscillation period. By adjusting sensitivity for fluctuating concentrations, these neurons improve the representation of the rate of the changing concentration. In other ON and OFF neurons, the response to changing concentrations is invariant to large variations in the rate of change due to variations in the oscillation period, facilitating odor identification in the antennal-lobe. The independent processing of odor identity and the temporal dynamics of odor concentration may speed up processing time and improve behavioral performance associated with plume tracking, especially when the air is not moving. [ABSTRACT FROM AUTHOR]

Background: In the 5 years that have passed since the publication of the 2018 International Consensus Statement on Allergy and Rhinology: Allergic Rhinitis (ICAR-Allergic Rhinitis 2018), the literature has expanded substantially. The ICAR-Allergic Rhinitis 2023 update presents 144 individual topics on allergic rhinitis (AR), expanded by over 40 topics from the 2018 document. Originally presented topics from 2018 have also been reviewed and updated. The executive summary highlights key evidence-based findings and recommendation fromthe full document. Methods: ICAR-Allergic Rhinitis 2023 employed established evidence-based reviewwith recommendation (EBRR) methodology to individually evaluate each topic. Stepwise iterative peer review and consensuswas performed for each topic. The final document was then collated and includes the results of this work. Results: ICAR-Allergic Rhinitis 2023 includes 10 major content areas and 144 individual topics related to AR. For a substantial proportion of topics included, an aggregate grade of evidence is presented, which is determined by collating the levels of evidence for each available study identified in the literature. For topics in which a diagnostic or therapeutic intervention is considered, a recommendation summary is presented, which considers the aggregate grade of evidence, benefit, harm, and cost. Conclusion: The ICAR-Allergic Rhinitis 2023 update provides a comprehensive evaluation of AR and the currently available evidence. It is this evidence that contributes to our current knowledge base and recommendations for patient evaluation and treatment. [ABSTRACT FROM AUTHOR]

Glucose aversion in the German cockroach, Blattella germanica (L.), results in behavioral resistance to insecticidal baits. Glucose-averse (GA) cockroaches reject foods containing glucose, even in relatively low concentrations, which protects the cockroaches from ingesting lethal amounts of toxic baits. Horizontal transfer of baits and the resulting secondary mortality have been documented in German cockroaches, including in insecticide resistant strains. However, the effects of the GA trait on secondary mortality have not been investigated. We hypothesized that ingestion of insecticide baits that contain glucose or glucose-containing disaccharides would result in behaviorally relevant glucose levels in the feces, possibly deterring coprophagy by GA nymphs. We fed adult female cockroaches hydramethylnon baits rich in either glucose, fructose, sucrose, or maltose and compared secondary mortality of GA and wild-type (WT) nymphs via coprophagy. When adult females were fed baits containing glucose, sucrose, or maltose and their feces offered to nymphs, secondary mortality was significantly lower in GA nymphs than in WT nymphs. However, survival of GA and WT nymphs was similar on feces generated by adult females fed fructose bait. Analysis of feces indicated that disaccharides in baits were hydrolyzed into glucose, some of which was excreted in the feces of females that ingested the bait. Based on these results, we caution that baits containing glucose or glucose-containing oligosaccharides may impede cockroach interventions; while GA adults and large nymphs avoid ingesting such baits, first instars reject the glucose-containing feces of any WT cockroaches that consumed the bait. [ABSTRACT FROM AUTHOR]

Insecticides are dedicated to impair the insect organisms, but also have an impact on other, non-target organisms, including humans. In this way, they became important risk factor for disturbance of physiological homeostasis and can be involved in the development of diseases or in deterioration of existing conditions. The influence of sublethal doses of various insecticides on vertebrates' and invertebrates' organisms has been previously observed. In this paper, we have evaluated the impact of exposure to extremely low dose of neurotoxin, bendiocarb (0.1 nM), a commonly used carbamate insecticide on a model organism in neurobiology—Periplaneta americana. The assessment was performed on all levels of animal organism from molecular (oxidative stress parameters: phosphorylation level of proteins, cAMP level, protein kinase A and C levels, and octopamine) to physiological (heart beat and gas exchange tests) and behavioral (motor skills assay, grooming test). Exposure to such a low level of bendiocarb did not cause direct paralysis of insects, but changed their grooming behavior, decreased heart rate, and increased gas exchange. We also observed the increased parameters of oxidative stress as well as stressogenic response to 0.1 nM bendiocarb exposure. Exposure to a trace amount of bendiocarb also increased sensitivity to effective doses of the same insecticide, thus acts as preconditioning. These results force us to reconsider the possible risk from frequent/continuous exposure to traces of pesticide residues in the environment to human health. [ABSTRACT FROM AUTHOR]

Globally the need to substitute fishmeal with other animal protein sources in the fish diet has gained more attention; which is occasioned by the increasing cost of fish. A 12-week trial was conducted to ascertain the growth indices and biochemical response of hybrid catfish (Clarias gariepinus(♀) and Heterobranchus bidorsalis (♂)) fed cockroach meal supplement. A total of 800 hybrid catfish were randomly distributed into four dietary treatments (Diet A- control feed), Diet B (50 % cockroach and 50 % fishmeal), Diet C (100 % cockroach meal) and Diet D (100 % fishmeal). Each treatment was replicated with 35 fish per experimental pond in a completely randomized design. Progressive weight gain was determined bi-weekly. At the end of the study period, fishes were randomly sacrificed for proximate compositions and plasma biochemical analyses (glucose, triglyceride, cholesterol, total protein, albumin) using standard protocols. The study revealed that growth parameters (Weight gain, Average weight gain, Protein efficiency ratio, Feed Conversion rate, Specific growth rate and Survival rate (SR) were influenced by the dietary treatments (p>0.05). The highest weight gain was recorded in Diet 1 (8847.73±292.65 g)>Diet 2 (7816.33±121.71 g)>Diet 3 (7811.67±566.08 g)>Diet 4 (7022.00±44.193 g). Similarly, the best feed conversion ratio was found in fish fed Diet A (10.12±0.01)>Diet B, C and D had the same values of 0.11 g respectively. There was no significant (p>0.05) difference in plasma biochemical indicators measured when compared to the control (Diet A). Thus, indicating that all the fish were healthy and had normal physiological activities. Cockroach meal can therefore, be used as a feed supplement without having any adverse effect on the growth and well-being of hybrid catfish fingerlings. [ABSTRACT FROM AUTHOR]

The German cockroach, Blattella germanica (L.), transmits a variety of pathogens and synthesizes nearly ten protein substances that trigger human allergies and asthma. With its strong fecundity and super resistance to various kinds of chemical pesticides, B. germanica is currently regarded as the most difficult to control global, household, insect pest. B. germanica uses sex pheromones for communication between the sexes. These pheromones are synthesized by sexually mature adult females. Their main function is to attract and stimulate male courtship and induce mating. Sex pheromone biosynthesis is therefore one of the core steps of sexual communication in this species. Articles on the regulation of sex pheromone synthesis in B. germanica have gradually increased in recent years, however, there has so far been no critical review summarizing progress and prospects for future research. This paper reviews important progress in research on contact sex pheromone biosynthesis and molecular regulation in B. germanica over the past three decades. It introduces researches on chemical composition and biosynthetic sites, focuses on the identification and characterization of key enzymatic genes involved in the sex pheromone biosynthesis pathway and the regulation of sex pheromone synthesis by the coordination between sex differentiation and juvenile hormone signaling. Prospects for future research are outlined with the aim of providing new theoretical support to develop new strategies for regulating cockroach behavior and new cockroach baits. [ABSTRACT FROM AUTHOR]

Animals with different life histories budget their intake energy differently when food availability is low. It has been shown previously that hornworm (larva of Manduca sexta), a holometabolous insect species with a short development stage, prioritizes growth at the price of metabolism under food restriction, but it is unclear how hemimetabolous insect species with a relatively long development period budget their intake energy under food scarcity. Here, we use orange head cockroaches (Eublaberus posticus) to investigate this question. We found that for both species under food restriction, rates of metabolism and growth were suppressed, but the degree of reduction was more severe in growth than that of metabolism for cockroaches. Under both free-feeding and food restriction conditions, hornworms allocated a larger fraction of assimilated energy to growth than to metabolism, and cockroaches were the opposite. More importantly, when food availability was low, the fraction of assimilated energy allocated to growth was reduced by 120% in cockroaches, and the energy from growth was channeled to compensate for the reduction in metabolism; but, the fraction of assimilated energy allocated to growth was only reduced by 14% in hornworms. These results suggest that, compared to hornworms, cockroaches prioritize metabolism over growth.

Toxicological studies have shown that the American cockroach Periplaneta americana (Linnaeus) is a classical model for studying the mode of action of commonly used insecticides. In a previous study, we demonstrated that thiamethoxam and clothianidin decreased locomotor activity in an open-field-like apparatus. Here, we tested the effect of the neonicotinoid acetamiprid when applied orally, topically, or injected into the haemolymph. We found that acetamiprid was also able to impair locomotor activity in the open-field-like apparatus. When treated with acetamiprid, a strong alteration in locomotor activity was observed 1 h, 24 h, and 48 h after haemolymph and topical applications. Oral application induced an impairment of locomotor activity at 24 h and 48 h. A comparison of the present data with our previously published results showed that neonicotinoids were more active when injected into the haemolymph compared to oral and topical applications. These findings increased our understanding of the effect of neonicotinoid insecticides on insect locomotor activity, and demonstrated that the cyano-substituted neonicotinoid, acetamiprid, was able to alter cockroach locomotor activity.

Abstract German cockroaches (Blattella germanica) can be both mechanical and biological (amplifying) vectors of enteric pathogens, including Salmonella enterica serovar Typhimurium (S. Typhimurium), which they acquire by feeding upon contaminated substances. Blattella germanica is also a gregarious species that shelters in groups and partakes in unique feeding behaviors such as conspecific coprophagy, necrophagy, and emetophagy. These properties create an interphase for potential horizontal transmission of pathogens among cockroach populations through the fecal‐oral route, which could in turn enhance transmission to humans and other animals. Here, we performed a series of experiments to determine: (1) whether horizontal transmission of S. Typhimurium infection takes place in B. germanica, (2) the prevalence of the phenomenon, and (3) the route(s) through which it may occur. We reveal that true horizontal transmission of S. Typhimurium occurs among B. germanica. That is, uninfected cockroaches acquire infection of the gut when co‐housed with orally infected conspecifics, albeit at low frequency. Furthermore, we provide definitive evidence that coprophagy and necrophagy are routes of transmission but could not exclude sharing of food or water as contributing routes. On the contrary, transmission by emetophagy appears less likely as oral regurgitates from infected cockroaches contained S. Typhimurium for less than one day after ingesting the bacteria. Together, our data enhance current understanding of the ecology of vector‐borne S. Typhimurium transmission by cockroaches, implicating conspecific horizontal transmission as a phenomenon that contributes to maintaining infected cockroach populations independently of contact with primary sources of the pathogen. Although the relative importance of horizontal transmission of pathogens in cockroaches in the field remains to be determined, these results also highlight the important role that food and water sources in the local environment may play in cockroach‐borne pathogen transmission and emphasize the importance of sanitation for not only abating infestations but also mitigating pathogen transmission.

Due to cockroaches' filthy habits and habitats, they are incriminated to mechanically disseminate a wide range of food-borne pathogens. This study was designed to examine the American cockroach (Periplaneta americana) as a carrier of bacteria and explore their risk to human health in Kuwait. From the 6 governorates of Kuwait, 600 cockroaches were collected for isolating and quantifying bacterial load using macroscopical, microscopical, and biochemical methods. A total of 20 bacterial isolates were determined by this study of which Escherichia coli was the most prevalent and Acinetobacter baumannii was the second dominant and as far as we are aware this is the first identification of this species on the American cockroach. Pseudomonas luteola and klebsiella pneumoniae were recognized as the least frequent bacteria. Several bacterial isolates were identified as highly pathogenic to humans such as Salmonella choleraesuis and Serratia marcescens and others. This study, which is regarded as the first study carried out in Kuwait, accentuated that the American cockroach is graded as a potential disseminator of life-threatening pathogenic agents and its public health implications should be highly considered. Hence, effective preventive and control measures are needed. [ABSTRACT FROM AUTHOR]

The decision to leave or join a group is important as group size influences many aspects of organisms' lives and their fitness. This tendency to socialise with others, sociability, should be influenced by genes carried by focal individuals (direct genetic effects) and by genes in partner individuals (indirect genetic effects), indicating the trait's evolution could be slower or faster than expected. However, estimating these genetic parameters is difficult. Here, in a laboratory population of the cockroach Blaptica dubia, I estimate phenotypic parameters for sociability: repeatability (R) and repeatable influence (RI), that indicate whether direct and indirect genetic effects respectively are likely. I also estimate the interaction coefficient (Ψ), which quantifies how strongly a partner's trait influences the phenotype of the focal individual and is key in models for the evolution of interacting phenotypes. Focal individuals were somewhat repeatable for sociability across a 3‐week period (R = 0.080), and partners also had marginally consistent effects on focal sociability (RI = 0.053). The interaction coefficient was non‐zero, although in opposite sign for the sexes; males preferred to associate with larger individuals (Ψmale = −0.129), while females preferred to associate with smaller individuals (Ψfemale = 0.071). Individual sociability was consistent between dyadic trials and in social networks of groups. These results provide phenotypic evidence that direct and indirect genetic effects have limited influence on sociability, with perhaps most evolutionary potential stemming from heritable effects of the body mass of partners. Sex‐specific interaction coefficients may produce sexual conflict and the evolution of sexual dimorphism in social behaviour. [ABSTRACT FROM AUTHOR]

Cockroaches pose a significant nuisance and public health threat due to their ability to transmit pathogenic organisms. The little attention given to the transmission of parasitic diseases by mechanical vectors such as cockroaches overwhelms the already fragile intestinal parasite prevention and control program. This study was conducted to assess species composition and parasite carriage rate of cockroaches among households in northeast Ethiopia. A community-based cross-sectional study was conducted among 402 households. A total of 1750 cockroaches were collected using jars. Species identification of cockroaches was done using taxonomic keys, and parasite isolation was done using formol-ether and modified acid-fast techniques. The data analysis was done using SPSS version 23. A p-value of less than 0.05 was considered statistically significant. All cockroaches collected were identified as a species of Blattella germanica (B. germanica). Overall, 36.0% of the cockroaches were found to harbor intestinal parasites, E. histolytica/dispar (14.3%) and H. nana (8.6%) being the predominant species. Improper latrine utilization (P = 0.006), presence of domestic animals (P = 0.032), and presence of a parasite-infected child in the household (P = 0.001) were significantly associated with parasite carriage of cockroaches. Moreover, houses attached via two or more sides with neighboring houses (P = 0.045), houses with cracks on their walls (P = 0.001), and households with poor solid waste disposal (P = 0.001) were significantly at higher odds of a cockroach infestation. Human and environmental factors have favored infestation by Blattella germanica in the study area. Therefore, household waste management systems should be improved. [ABSTRACT FROM AUTHOR]

Only a few cases of Moniliformis moniliformis infection have been reported in humans worldwide. In this paper, we report a case of infection with M. moniliformis, which passed in the stool of a 16-month-old boy in Uzbekistan. patient had abdominal pain, nausea, and one episode of vomiting. The child’s mother reported that she often saw insects in the house, particularly cockroaches, and that the child might have swallowed beetles or cockroaches because he often took various small objects in his mouth. In a stool examination, eggs of M. moniliformis were not found. The patient was treated with albendazole, and the clinical symptoms reduced within 2 weeks. A stool sample contained an adult parasite with a length of 165 mm and a diameter of 2.0-2.5 mm; based on the size, this worm was likely a female. The parasite was white in colour, and it had a segmented appearance because of indented horizontal lines on the surface of its body. No cases of M. moniliformis infection have previously been reported in Uzbekistan. This is the 1st case of M. moniliformis infection in Uzbekistan.