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The majority of terrestrial plants can form symbiotic associations on their roots with arbuscular mycorrhizal fungi (AMF) in the soil to stimulate the growth and nutrient uptake of the host plant and to improve plant resistance to insects and disease. However, the use of AMF for insect control on gramineous forages requires further study. Here, we evaluated the effects of AMF (Funneliformis mosseae) inoculation on the defense against Locusta migratoria attack in Elymus nutans. Inoculation assays showed that mycorrhizal plants had a higher resistance than non-inoculated plants, as evidenced by plants having more plant biomass, a higher nitrogen and phosphorus content, and greater lipoxygenase (LOX) activity. The results of insect damage showed that in addition to a decrease in the enzyme phenylalanine-ammonia-lyase, the activities of other plant defense-related enzymes (including polyphenol oxidase and β-1,3-glucanase) were increased. A key enzyme, LOX, belonging to the jasmonic acid (JA) signaling pathway was notably increased in mycorrhizal treatment. Volatile organic compounds (VOCs) were identified using gas chromatography mass spectrometry and the results showed that several metabolites with insect-resistant properties, including D-Limonene, p-Xylene, 1,3-Diethylbenzene were detected in mycorrhizal plants. These findings suggest that mycorrhizal inoculation has potential applications in insect management on forage grasses and demonstrates that the JA signaling pathway is essential for insect resistance in Elymus nutans. [ABSTRACT FROM AUTHOR]

This loss of our close friend and honorable companion has struck us unexpectedly, because Jochen was highly active, full of infectious energy and exciting future projects. Jochen - beyond the bench Jochen was that kind of German university faculty member who was of the strong belief that universities and research institutions need people to actively "run the show" and to assume ownership in building a high-quality professional environment for all other staff associates. In doing so, Jochen contributed to the development of neurobiology and biology at the FU Berlin in serving his I alma mater i in various administrative roles, for example, as Managing Director of the Institute of Neurobiology, as Dean of the Faculty of Pharmacy, Chemistry and Biology and as an elected member in the FU Senate. Far too early has our colleague, Professor Hans-Joachim ' I Jochen i ' Pflüger, passed away on January 25, 2022, only 72 years old. [Extracted from the article]

A trypsin affinity material was prepared by covalently immobilizing buckwheat trypsin inhibitor (BTI) on epichlorohydrin-activated cross-linked agarose gel (Selfinose CL 6 B). The optimal conditions for activating Selfinose CL 6 B were 15 % epichlorohydrin and 0.8 M NaOH at 40 °C for 2 h. The optimal pH for immobilizing BTI was 9.5. BTI-Sefinose CL 6 B showed a maximum adsorption capacity of 2.25 mg trypsin/(g support). The material also displayed good reusability, retaining over 90 % of its initial adsorption capacity after 30 cycles. High-purity trypsin was obtained from locust homogenate using BTI-Selfinose CL 6 B through one-step affinity chromatography. The molecular mass and K m value of locust trypsin were determined as 27 kDa and 0.241 mM using N-benzoyl-DL-arginine-nitroanilide as substrate. The optimal temperature and pH of trypsin activity were 55 °C and 9.0, respectively. The enzyme exhibited good stability in the temperature range of 30–50 °C and pH range of 4.0–10.0. BTI-Selfinose CL 6 B demonstrates potential application in the preparation of high-purity trypsin and the discovery of more novel trypsin from various species. • A low-cost and non-toxic trypsin affinity material was prepared. • An efficient and simple method for trypsin purification was developed. • A trypsin from the oriental migratory locust was purified for the first time. • BTI is an excellent ligand for trypsin affinity materials. [ABSTRACT FROM AUTHOR]

This study investigated the in vitro bioaccessibility of aluminum, copper, iron, manganese, lead, selenium, and zinc in three important species of farmed insects: the yellow mealworm (Tenebrio molitor) , the house cricket (Acheta domesticus) and the migratory locust (Locusta migratoria). Results show that all three insect species constitute excellent sources of essential elements (Fe, Cu and Zn) for the human diet, contributing to the recommended dietary allowance, i.e. , 10%, 50%, and 92%, respectively. A higher accumulation of Se (≥1.4 mg Se/kg) was observed with increasing exposure concentration in A. domesticus , showing the possibility of using insects as a supplements for this element. The presence of Al and Fe nanoparticles was confirmed in all three species using single particle-inductively coupled plasma-mass spectrometry and transmission electron microscopy. The results also indicate that Fe bioaccessibility declines with increasing Fe-nanoparticle concentration. These findings contribute to increase the nutritional and toxicological insights of farmed insects. • Studied insects provide excellent sources of Fe, Cu, and Zn for the human diet. • Selenium-enriched diets significantly boost selenium levels in A. domesticus. • A higher presence of Fe-nanoparticles reduced Fe bioaccessibility. • Whether as nanoparticles or in ionic form, Al bioaccessibility remains below 10%. [ABSTRACT FROM AUTHOR]

The representation of odors in the locust antennal lobe with its >2,000 glomeruli has long remained a perplexing puzzle. We employed the CRISPR-Cas9 system to generate transgenic locusts expressing the genetically encoded calcium indicator GCaMP in olfactory sensory neurons. Using two-photon functional imaging, we mapped the spatial activation patterns representing a wide range of ecologically relevant odors across all six developmental stages. Our findings reveal a functionally ring-shaped organization of the antennal lobe composed of specific glomerular clusters. This configuration establishes an odor-specific chemotopic representation by encoding different chemical classes and ecologically distinct odors in the form of glomerular rings. The ring-shaped glomerular arrangement, which we confirm by selective targeting of OR70a-expressing sensory neurons, occurs throughout development, and the odor-coding pattern within the glomerular population is consistent across developmental stages. Mechanistically, this unconventional spatial olfactory code reflects the locust-specific and multiplexed glomerular innervation pattern of the antennal lobe. [Display omitted] • A transgenic line was established to express GCaMP6s in olfactory sensory neurons • Calcium imaging reveals a functionally ring-shaped odor code of glomerular clusters • Distinct ring regions encode chemical identity and ecological significance • The ring-shaped odor-coding pattern occurs consistently throughout development Migratory locusts, genetically expressing the calcium sensor GCaMP6s in olfactory sensory neurons, have an unconventional, ring-shaped olfactory code of glomerular clusters in the antennal lobe, a pattern that occurs consistently throughout development. [ABSTRACT FROM AUTHOR]

• UVB-treatment leads to vitamin D 3 formation in powdered mealworms. • Migratory locusts and two-spotted crickets contained no detectable amounts of vitamin D 3. • Few grams of UVB-treated mealworm suffice to fulfil daily needs for vitamin D. • UVB-treated mealworms are a promising ingredient for food fortification. Edible insects are attracting increased interest worldwide, because they are arguably more sustainable than more established animal foods. Apart from being rich in protein and minerals, they can also form vitamin D 3 after treatment with UVB light (290–315 nm). However, only limited research, which has almost exclusively been conducted on living insects, reared under UVB lamps, has been done in this regard. As research on mushrooms has shown, that vitamin D formation is much more effective and less time consuming, when a previously sliced or ground product is treated with UVB light, it would likely be more practical to treat powdered insects with UVB light, rather than rearing them under UVB lamps. Therefore, the aim of this work was to confirm the presence of vitamin D 3 in powdered UVB-treated yellow mealworms (Tenebrio molitor), migratory locusts (Locusta migratoria) and two-spotted crickets (Gryllus bimaculatus) as well as to subsequently quantify potential vitamin D content. Samples were analyzed via HPLC, and presence of vitamin D 3 was verified via standard addition and spectrum analysis. UVB-treated migratory locusts and two-spotted crickets did not contain quantifiable amounts of vitamin D 3. However, UVB-treated mealworms showed substantial amounts of vitamin D 3 (8.95–18.24 µg/g dry matter). Thus, the UVB-treatment of powdered mealworm is an effective approach via which to enhance their vitamin D 3 content and even modest serving sizes can supply the recommended daily intake of vitamin D. [ABSTRACT FROM AUTHOR]

Syntaxin5 (Syx5) belongs to SNAREs family, which play important roles in fusion of vesicles to target membranes. Most of what we know about functions of Syx5 originates from studies in fungal or vertebrate cells, how Syx5 operates during the development of insects is poorly understood. In this study, we investigated the role of LmSyx5 in the gut development of the hemimetabolous insect Locusta migratoria. LmSyx5 was expressed in many tissues, with higher levels in the gut. Knockdown of LmSyx5 by RNA interference (RNAi) considerably suppressed feeding in both nymphs and adults. The ds LmSyx5- injected locusts lost body weight and finally died at a mortality of 100%. Furthermore, hematoxylin-eosin staining indicated that the midgut is deformed in ds LmSyx5 -treated nymphs and the brush border in midgut epithelial cells is severely damaged, suggesting that LmSyx5 is involved in morphogenesis of the midgut. TEM further showed that the endoplasmic reticulum of midgut cells have a bloated appearance. Taken together, these results suggest that LmSyx5 is essential for midgut epithelial homeostsis that affects growth and development of L. migratoria. Thus, Syx5 is a promising RNAi target for controlling L. migratoria , and even other pests. [Display omitted] • Knockdown of LmSyx5 caused 100% mortality by regulating feeding. • LmSyx5 plays important roles in the development of the midgut. • The endoplasmic reticulum morphology required LmSyx5 function. [ABSTRACT FROM AUTHOR]

• Locust, cricket, and mealworm powders were abundant in bioactive compounds. • Following a 5% inclusion, mealworm-burgers showed the higher sensory acceptability. • Cricket powder (CP) reduced the accumulation of heterocyclic amines following cooking. • Dipeptides, such as glutaminylarginine, are biomarkers of in vitro digested CP-burgers. • A potential enzyme modulating activity was recorded for CP-burgers at intestinal level. Mealworm (MWP), migratory locust (LP), and house cricket (CP) are novel foods recently authorized by the European Commission. This work tested their powders as meat extenders at 5% inclusion in beef burgers. Insect powders were abundant in phenolics, recording the highest values in LP (1184.9 μg/g). The sensory analysis highlighted a higher visual and olfactory acceptability for MWP-burgers, followed by CP- and LP-burgers, whereas the texture of cooked burgers remained unaffected. Following pan-cooking, MWP-burgers and control exhibited comparable chemical profiles, while a significant down-accumulation of the heterocyclic amine 2-Amino-3,8-dimethylimidazo[4,5- f ]quinoxaline was observed in CP-burgers. In vitro gastrointestinal digestion highlighted metabolomic trends like control for MWP- and LP-burgers. In contrast, a reduced accumulation of lipids and increased content of dipeptides like glutaminylarginine (possibly acting as enzyme modulators) was observed for the CP-burgers. [ABSTRACT FROM AUTHOR]

The coat protein II (COPII) complex consists of five primary soluble proteins, namely the small GTP-binding protein Sar1, the inner coat Sec23/Sec24 heterodimers, and the outer coat Sec13/Sec31 heterotetramers. COPII is essential for cellular protein and lipid trafficking through cargo sorting and vesicle formation at the endoplasmic reticulum. However, the roles of COPII assembly genes remain unknown in insects. In present study, we identified five COPII assembly genes (LmSar1 , LmSec23 , LmSec24 , LmSec13 and LmSec31) in Locusta migratoria. RT-qPCR results revealed that these genes showed different expression patterns in multiple tissues and developmental days of fifth-instar nymphs. Injection of double-stranded RNA against each LmCOPII gene induced a high RNAi efficiency, and considerably suppressed feeding, and increased mortality to 100 %. Results from the micro-sectioning and hematoxylin–eosin staining of midguts showed that the brush border was severely damaged and the number of columnar cells was significantly reduced in ds LmCOPII -injected nymphs, as compared with the control. The dilated endoplasmic reticulum phenotype of columnar cells was observed by transmission electron microscopy. RT-qPCR results further indicated that silencing any of the five genes responsible for COPII complex assembly repressed the expression of genes involved in insulin/mTOR-associated nutritional pathway. Therefore, COPII assembly genes could be promising RNAi targets for insect pest management by disrupting gut and cuticle development. [ABSTRACT FROM AUTHOR]

The Osiris gene family is believed to play important roles in insect biology. Previous studies mainly focused on the roles of Osiris in Drorophila , how Osiris operates during the development of other species remains largely unknown. Here, we investigated the role of LmOsi17 in development of the hemimetabolous insect Locusta migratoria. LmOsi17 was highly expressed in the intestinal tract of nymphs. Knockdown of LmOsi17 by RNA interference (RNAi) in nymphs resulted in growth defects. The ds LmOsi17 -injected nymphs did not increase in body weight or size and eventually died. Immunohistochemical analysis showed that LmOsi17 was localized to the epithelial cells of the foregut and the gastric caecum. Histological observation and hematoxylin-eosin staining indicate that the foregut and gastric caecum are deformed in ds LmOsi17 treated nymphs, suggesting that LmOsi17 is involved in morphogenesis of foregut and gastric caecum. In addition, we observed a significant reduction in the thickness of the new cuticle in ds LmOsi17 -injected nymphs compared to control nymphs. Taken together, these results suggest that LmOsi17 contributes to morphogenesis of intestinal tract that affects growth and development of nymphs in locusts. [Display omitted] • LmOsi17 is highly expressed in the intestinal tract of locusts. • Knockdown of LmOsi17 disrupts nymphal growth and development. • LmOsi17 is required for morphogenesis of gastric caecum and foregut. • New cuticle thickening is affected in LmOsi17 silenced nymphs. [ABSTRACT FROM AUTHOR]

The stability of symbiotic flora is an important indicator of the health of an organism. Symbiotic bacteria have been proven to be closely involved in the immune process of organisms. The pathogenicity of Beauveria bassiana was studied in relation to symbiotic bacteria on the surface and inside of the migratory locust (Locusta migratoria). The results showed that the surface disinfection of test locusts contributed to the pathogenicity of B. bassiana to locusts. Most of the surface bacteria of L. migratoria caused some inhibition of B. bassiana growth, and LM5-4 (Raoultella ornithinolytica), LM5-2 (Enterobacter aerogenes), and LM5-13 (Citrobacter freundii) showed the highest inhibitory effect on the growth of B. bassiana. The inoculation of locusts with additional surface symbiotic bacteria reduced the virulence of B. bassiana to L. migratoria. Infection by different strains of B. bassiana caused similar changes in the symbiotic flora of migratory locusts. The inoculation of locusts with additional intestinal symbiotic bacteria (Enterobacter sp.) reduced the virulence of B. bassiana to L. migratoria. These findings illustrate the effect of bacterial communities on fungal infections in L. migratoria when seen from the perspective of ecology in a microenvironment. The active antifungal substances of such bacteria and their mechanisms of action need further study.

Ecdysone‐induced protein 93F (E93) plays important roles during the metamorphosis process in insects. In this study, a cDNA of the LmE93 gene was identified from the transcriptome of Locusta migratoria, which consists of the 3378‐nucleotide open‐reading frame (ORF) and encodes 1125 amino acids with helix–turn–helix (HTH) motifs. Reverse transcription quantitative polymerase chain reaction analysis revealed that LmE93 was highest expressed in ovary. The LmE93 expression level was markedly low from the 3rd to 4th instar nymphs, and greatly increased in 1‐day‐old 5th instar nymphs with a peak on middle nymphal days, then declined in the late nymphal days. Moreover, injected dsLmE93 into 4th and 5th instar nymphs greatly reduced LmE93 transcripts, respectively, and prevented the process of metamorphosis, causing supernumerary nymphal stages. Hematoxylin–eosin staining of the integument showed that the apolysis occurred in advance in 4th instar nymphs, and old cuticle degradation was decreased in dsLmE93‐injected locusts of 5th instar nymphs. Smaller and no fully developed wings with reduced columns between the anterior and posterior regions were found in N6 and N7 supernumerary nymphs. In addition, the development of the ovary in dsLmE93‐injected locusts was severely blocked, the yolk was almost not formed and there was no development of ovarioles. The results indicated that LmE93 play key roles in the metamorphosis, cuticle, wing and ovarian development of locusts. [ABSTRACT FROM AUTHOR]

Rab proteins constitute the largest family of small GTPases, which play pivotal roles in intracellular membrane trafficking in all eukaryotes. A number of Rab genes have been identified in eukaryotes; however, very little information about these genes has been reported in insects. In the current study, for the first time we identified and characterized 27 Rab family genes from Locusta migratoria. Phylogenetic analysis and comparison of domain architecture indicated that Rab family genes are highly conserved among insect species. Tissue‐dependent expression profiles indicated that expression of Rab genes was highest in the ovary, except for LmRab3, which was most highly expressed in hemolymph. The biological function of each Rab gene was investigated using RNA interference (RNAi). Double‐stranded RNA targeting each Rab gene was injected into the hemocoel of nymphs and revealed that suppression of two Rab genes (LmRab5 and LmRab11A) caused 100% mortality. In addition, nymphs injected with dsLmRab5 exhibited severe phenotypic defects in the gastric caeca and midgut, while dsLmRab11A arrested the molting process. We then applied the RNAi of RNAi technique to test if silencing either of these two genes would affect the suppression of the lethal giant larvae (LmLgl) reporter gene and found that suppression of LmRab5 diminished the RNAi efficiency of LmLgl, whereas suppression of LmRab11A enhanced RNAi efficiency of LmLgl. These results indicate that Rab genes contribute differently to RNAi efficiency in different tissues. Our study provides a foundation for further functional investigations of Rab genes and their contributions to RNAi efficiency in L. migratoria. [ABSTRACT FROM AUTHOR]

The migratory locust is global problem and a threat to food security for their large-scale devastation to the diversified agro-ecosystem. GIS-based analysis found recent locust movement, with Schistocerca gregaria and Locusta migratoria being the most common and destructive species in the Indian subcontinent. To save the human species from starvation, this destructive species must be halted. In this study, we evaluated some commonly used agricultural pesticides against S. gregaria lipid-binding protein and muscle fatty acid-binding protein, as well as L. migratoria fatty acid-binding protein from flight muscle and odorant binding protein, and three pesticides, i.e., biphenthrin, diafenthiuron, and silafluofen showed maximum binding affinity with all key proteins in terms of lowest global binding energy. Our phylogenetic analysis demonstrates that these three pesticides are likely to be effective against other locust species, and they are also far safer than other currently used pesticides. These proposed pesticide's bioactive analogs from fungus and bacteria may also show efficacy as next-generation controlling measures of locust as well as different kind of pests. These pesticides are projected to be particularly effective against locusts, and they will need to be brought forward by entomologists and plant biotechnologists through field experiments. [ABSTRACT FROM AUTHOR]

Behavioral plasticity and the underlying neuronal plasticity represent a fundamental capacity of animals to cope with environmental stimuli. Behavioral plasticity is controlled by complex molecular networks that act under different layers of regulation. While various molecules have been found to be involved in the regulation of plastic behaviors across species, less is known about how organisms orchestrate the activity of these molecules as part of a coherent behavioral response to varying environments. Here we discover a mechanism for the regulation of animal behavioral plasticity involving molecular sulfation in the brain, a modification of substrate molecules by sulfotransferase (ST)-catalyzed addition of a sulfonate group (SO3) from an obligate donor, 3′-phosphoadenosine 5′-phosphosulfate (PAPS) to the substrates. We investigated aggregation behaviors of migratory locusts, which are well-known for extreme phase change plasticity triggered by population density. The processes of PAPS biosynthesis acted efficiently on induction of locust behavioral transition: Inhibition of PAPS synthesis solicited a behavioral shift from gregarious to solitarious states; external PAPS dosage, by contrast, promoted aggregation in solitarious locusts. Genetic or pharmacological intervention in the sulfation catalyzation resulted into pronounced solitarizing effects. Analysis of substrate-specific STs suggests a widespread involvement of sulfated neurotransmitters in the behavioral response. Dopamine in the brain was finally identified to be actively sulfate conjugated, and the sulfate conjugation enhanced the free DA-mediated behavioral aggregation. Similar results in Caenorhabditis elegans and mice indicate that sulfation may be involved more broadly in the modulation of animal aggregation. These findings reveal a general mechanism that effectively regulates animal social-like behavioral plasticity, possibly through sulfation-mediated modification of neural networks. [ABSTRACT FROM AUTHOR]

Insects prevent uncontrolled penetration of water and xenobiotics by producing an impermeable cuticle. The major component of the cuticle is chitin that adopts a crystalline structure thereby contributing to cuticle stability. Our understanding of the contribution of chitin to the cuticle barrier function is limited. Here, we studied the role of the DOMON domain protein Knickkopf (LmKnk) that is involved in chitin organization and cuticle permeability in the migratory locust Locusta migratoria. We show that LmKnk localizes to the chitin layer in the newly produced cuticle. Injection of double‐stranded RNA targeting LmKnk (dsLmKnk) in locust nymphs caused failure of moulting to the next stage. Histological experiments revealed that apolysis, i.e., the detachment of the old cuticle from the body surface, was normal; however, the newly synthesized cuticle was thinner than the cuticle of the control insects. Indeed, chitin content dropped after suppression of LmKnk expression. As seen by transmission electron microscopy, crystalline chitin organization was lost in dsLmKnk‐treated insects. In addition, the structure of pore canals, which are lipid transporting routes in the cuticle, was abnormal. Consistently, their content was reduced and, probably by consequence, lipid deposition on the cuticle was decreased after injection of dsLmKnk. Suppression of LmKnk transcript levels rendered L. migratoria more susceptible to each of four selected insecticides including malathion, chlorpyrifos, carbaryl and deltamethrin. Overall, our data show that LmKnk is needed for correct chitin amounts and organization, and their changes ultimately affect cuticular permeability in L. migratoria. [ABSTRACT FROM AUTHOR]

In Zwierzyniec (Lublin province), a stone commemorates the victory over locusts, which, according to the carved inscription, appeared in Roztocze on 26 August 1711. This date was inscribed during the renovation of the monument in the 21st century, when the previous date – 27 August 1859 – was removed. However, both versions of the date are incorrect. The article presents the history of the monument based on previously unknown sources, identifi es the person who founded it, and describes the insect invasion and measures taken to destroy the locusts that, in reality, affected this area in 1860. [ABSTRACT FROM AUTHOR]

Background: Vacuolar (H+)‐ATPase (V‐ATPase) is a multi‐subunit enzyme that hydrolyzes adenosine triphosphate (ATP) to transport protons across a cellular membrane, and it plays an important role in numerous biological processes, including in growth, development and immune responses. The c subunit of V‐ATPase is a highly conserved subunit of the rotatory proteolipid ring that is required for binding and transporting protons. To date, there are only a few published reports on V‐ATPase‐c functions in insects. Results: We identified and characterized the V‐ATPase‐c gene in Locusta migratoria, one of the most destructive agricultural insect pests in the world. LmV‐ATPase‐c was predominately expressed in Malpighian tubules of nymphs, followed by the hindgut and ovary, while the other tissues showed relatively low expression levels. Silencing of LmV‐ATPase‐c caused severe molting defects in nymphs and a high mortality rate of > 90%. Histological staining and microscopic examination of sections from the abdominal cuticle revealed the absence of newly formed cuticle in nymphs that were injected with dsLmV‐ATPase‐c. In addition, silencing of LmV‐ATPase‐c transcript levels significantly impaired RNA interference (RNAi) efficiency of a reporter gene. By quantifying double‐stranded RNA (dsRNA) amounts by quantitative polymerase chain reaction (PCR), we found that RNAi against LmV‐ATPase‐c provoked a dramatic accumulation of dsRNA in the endosomes of epidermal and midgut cells of Locusta migratoria. Conclusion: Our results indicate that LmV‐ATPase‐c is indispensable for the formation of new cuticle during the molting process and has pivotal functions in dsRNA escape from endosomes. LmV‐ATPase‐c might be a valuable target for developing new strategies for insect pest management. © 2022 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

RNA interference (RNAi) induces gene silencing in order to participate in immune-related pathways. Previous studies have shown that the LmSerpin1 gene upregulates the immune responses of Locusta migratoria manilensis, and that the infection of locusts with Metarhizium anisopliae can be enhanced through the injection of the interfering dsSerpin1. In this study, dsRNA was synthesized from the Serpin1 gene and fed to the third instars of L. m. manilensis at concentrations of 5 μg, 10 μg, and 20 μg. Feeding dsSerpin1 increased the mortality of L. m. manilensis, and 20 μg dsSerpin1 had the highest lethality, followed by 10 μg dsSerpin1, with the lowest being observed at 5 μg dsSerpin1. Serpin1 silencing and temperature fever induction by feeding with dsSerpin1 had a strong synergistic effect on M. anisopliae, showing a dose-dependent response. When L. m. manilensis were fed on a diet containing 20 μg dsRNA and M. anisopliae (2.5 × 108 spores/g wheat bran), 3-day mortalities significantly increased. The dsSerpin1 plus M. anisopliae treatments resulted in a 6-day mortality of 60%, accelerating insect death. These results indicated that feeding with dsSerpin1 could be an effective way to control pests and that the control effect and dsRNA concentration were dose-dependent within the first seven days. In particular, 20 μg was an effective dosage to enhance the insecticidal efficiency of M. anisopliae. [ABSTRACT FROM AUTHOR]

Inhalation anesthetics isoflurane and sevoflurane have been widely used in clinical practice for anesthesia. However, the molecular mechanisms underlying the faster recovery from sevoflurane anesthesia than isoflurane anesthesia remain largely undetermined. Herein, we use RNA-seq, RNA interference, quantitative real-time PCR and western blotting to explore the mechanisms of recovery from isoflurane and sevoflurane anesthesia in the migratory locusts. Although the migratory locusts show similar anesthetic responses to these two chemicals in corresponding half-maximal effective concentrations (EC50s), the recovery from sevoflurane anesthesia is significantly faster than that for isoflurane anesthesia after 30 min of anesthetic exposure. Transcriptome analysis shows that those transcripts involved in cytoskeletal components, Janus kinase (JAK) pathway and cuticle protein are differentially expressed in locust brains in response to isoflurane and sevoflurane. RNAi knockdown confirms that Actin , Myosin-like protein 84B (Mlp84B), JAK and cuticle protein NCP56 do not affect anesthetic response of the locusts to these two chemical anesthetics. Moreover, actin , Mlp84B and NCP56 do not affect differential recovery from isoflurane and sevoflurane anesthesia, whereas RNAi knockdown of JAK and its partner STAT5B does not affect anesthetic recovery from isoflurane but elongates recovery duration from sevoflurane anesthesia. Thus, JAK may mediate faster recovery from sevoflurane anesthesia than from isoflurane anesthesia in the migratory locust. This finding provides novel insights into the molecular mechanism underlying faster recovery from sevoflurane anesthesia than isoflurane anesthesia. [ABSTRACT FROM AUTHOR]

Insect wing consists of a double layer of epidermal cells that produce and secrete the dorsal and ventral cuticular components. It is important for the stability of epidermal cells during wing development and morphogenesis, but its specific gene expression and physiological function during this process remain unclear. In our previous work, a wing cuticle protein gene LmACP19 was identified in Locusta migratoria based on transcriptomic data. Here, we report on its roles in wing development and morphogenesis. LmACP19 encodes a chitin-binding protein belonging to RR-2 subfamily of CPR family, which is highly homologous to CP19-like proteins in other insect species. RT-qPCR analysis revealed that LmACP19 is highly expressed in wing pads of fifth-instar nymphs, and its encoded protein is located in two layers of epidermal cells but not in the cuticle. Suppression of LmACP19 by RNA interference led to abnormal wing pad and wing morphogenesis with curved, unclosed, and wrinkled phenotypes during nymph-to-nymph and nymph-to-adult transition, respectively. Furthermore, deficiency of LmACP19 affected arrangement of epidermal cells, resulting in apoptosis. Our results indicate that LmACP19 is indispensable for wing development and normal morphological structure by maintaining the stability of epidermal cells during L. migratoria molting. [ABSTRACT FROM AUTHOR]

Reproductive synchrony generally occurs in various group-living animals. However, the underlying mechanisms remain largely unexplored. The migratory locust, Locusta migratoria, a worldwide agricultural pest species, displays synchronous maturation and oviposition when forms huge swarm. The reproductive synchrony among group members is critical for the maintenance of locust swarms and population density of next generation. Here, we showed that gregarious female locusts displayed more synchronous sexual maturation and oviposition than solitarious females and olfactory deficiency mutants. Only the presence of gregarious male adults can stimulate sexual maturation synchrony of female adults. Of the volatiles emitted abundantly by gregarious male adults, the aggregation pheromone, 4-vinylanisole, was identified to play key role in inducing female sexual maturation synchrony. This maturation-accelerating effect of 4-vinylanisole disappeared in the females of Or35-/- lines, the mutants of 4-vinylanisole receptor. Interestingly, 4-vinylanisole displayed a time window action by which mainly accelerates oocyte maturation of young females aged at middle developmental stages (3–4 days post adult eclosion). We further revealed that juvenile hormone/vitellogenin pathway mediated female sexual maturation triggered by 4-vinylanisole. Our results highlight a ‘catch-up’ strategy by which gregarious females synchronize their oocyte maturation and oviposition by time-dependent endocrinal response to 4-vinylanisole, and provide insight into reproductive synchrony induced by olfactory signal released by heterosexual conspecifics in a given group. [ABSTRACT FROM AUTHOR]

The fungal strain BS5 was isolated from a soil sample collected in the Tibetan Plateau, which displayed good insecticidal activity and was identified as Talaromyces purpureogenus based on morphological and molecular analysis. This study aimed to evaluate the insecticidal activity and identify the active compound of the strain BS5 against the locust Locusta migratoria manilensis. The insecticidal activity of the fermented broth of BS5 was at 100% after 7 days against locusts. We extracted the fermented broth of BS5 and then evaluated the insecticidal activity of the extracts against locusts. The ethyl acetate extract exhibited promising activity levels with an LC50 value of 1077.94 μg/mL and was separated through silica gel column chromatography. The UPLC-Q-Exactive Orbitrap/MS system was employed to analyze the active fraction Fr2.2.2 (with an LC50 value of 674.87 μg/mL), and two compounds were identified: phellamurin and rubratoxin B. [ABSTRACT FROM AUTHOR]

Simple Summary: Tudor domain-containing proteins (TDRDs) are a group of evolutionarily conserved and germline-enriched proteins, and most of them function in reproduction and the P-element-induced wimpy testis-interacting RNA (piRNA) pathway. We investigated LmTDRD5, a TDRD5 ortholog in Locusta migratoria. In males, LmTdrd5 knockdown delayed meiosis phase transition and reduced the number of elongated spermatids and sperm count. The expression levels of two haploid germ cell marker genes, LmCREM and LmACT, as well as the sperm tail marker gene LmQrich2 were downregulated. In females, LmTdrd5 knockdown decreased vitellogenin (Vg) and Vg receptor (VgR) transcript levels, thereby affecting ovarian development and oocyte maturation. Therefore, LmTdrd5 may play an important role in locust reproduction, indicative of a conserved primary function of TDRD5. Tudor family proteins exist in all eukaryotic organisms and play a role in many cellular processes by recognizing and binding to proteins with methylated arginine or lysine residues. TDRD5, a member of Tudor domain-containing proteins (TDRDs), has been implicated in the P-element-induced wimpy testis-interacting RNA (piRNA) pathway and germ cell development in some model species, but little is known about its function in other species. Therefore, we identified and characterized LmTDRD5, the TDRD5 ortholog in Locusta migratoria, a hemimetabolous pest. The LmTdrd5 gene has 19 exons that encode a protein possessing a single copy of the Tudor domain and three LOTUS domains at its N-terminus. qRT-PCR analysis revealed a high LmTdrd5 expression level in genital glands. Using RNA interference, LmTdrd5 knockdown in males led to a lag in meiosis phase transition, decreased spermatid elongation and sperm production, and downregulated the expression of the two germ cell-specific transcription factors, LmCREM and LmACT, as well as the sperm tail marker gene LmQrich2.LmTdrd5 knockdown in females reduced the expression levels of vitellogenin (Vg) and Vg receptor (VgR) and impaired ovarian development and oocyte maturation, thus decreasing the hatchability rate. These results demonstrate that LmTdrd5 is essential for germ cell development and fertility in locusts, indicating a conserved function for TDRD5. [ABSTRACT FROM AUTHOR]

The article presents study on relation between desert locust (Schistocerca gregaria) incidences and rainfall during southwest monsoon season over West Rajasthan, India. It reports that Locust are short horned grasshoppers that change their behaviour and appearance switching from solitary lifestyle to gregarious group of bright coloured swarms (adults) and hopper bands (nymphal congregation) causing severe damage to vegetation due to their voracious feeding habit.

With the wide application of genome editing in insects, a simple and efficient identification method is urgently needed to meet the increasing demand for mutation detection. Here, taking migratory locusts as a model system, we developed a non‐invasive method to accurately identify genome‐edited mutants by using DNA from insect exuviae. We compared the quantity and quality of genomic DNA from exuviae in five instar hoppers and found that the 1st instar exuviae had the highest DNA yield and content, while the 3rd instar exuviae had the best quality. Consensus genotypes were identified from genomic DNA of hoppers at different developmental stages in the same individuals. Moreover, we demonstrated that the amplification products from DNA extracted from locust exuviae are the consensus sequences with those from the hemolymph and foreleg pre‐tarsus. Therefore, non‐invasive samples provide the same genotyping results as minimally invasive and invasive samples of the same individuals. Furthermore, this identification method that uses genomic DNA from exuviae can be used for early screening of positive genome‐edited individuals in each generation for adult crossing. In our study, the non‐invasive identification method was not only simpler and provided results earlier than existing methods, but also had a better reproducibility and accuracy. This non‐invasive identification approach using genomic DNA from exuviae can be adapted to meet the growing demand for genetic analysis and will find wide application in insect genome editing research. [ABSTRACT FROM AUTHOR]

Halloween genes are involved in the biosynthesis of the molting hormone, which plays a key role in insect ecdysis, development, metamorphosis, and reproduction. Our previous work identified five Halloween genes from Locusta migratoria, but their functions are currently unknown. In this study, the sequences of these five Halloween genes were analyzed and characterized. LmCYP307a2, LmCYP306a1, LmCYP302a1, and LmCYP315a1 were primarily expressed in the prothoracic glands, while LmCYP314a1 was universally expressed in peripheral tissues, especially in the ovaries and Malpighian tubules. All five Halloween genes were mainly expressed from the 5th to the 7th d in 5th‐instar nymphs. RNA interference (RNAi) silencing of LmCYP307a2 resulted in severe molting delays and molting failure, which could be rescued by supplementary 20‐hydroxyecdysone. A hematoxylin and eosin staining analysis suggested that the RNAi of LmCYP307a2 inhibited the ecdysis process by inhibiting the apolysis and degradation of the old cuticle, and by promoting the synthesis of a new cuticle. Quantitative reverse transcription polymerase chain reaction results showed that the expressions of LmE74, LmCht5, and LmCht10 were dramatically down‐regulated, while that of LmChsI was substantially up‐regulated, after knockdown of LmCYP307a2. The results suggest that LmCYP307a2 is related to the molt process via regulation of chitin synthesis and degradation. [ABSTRACT FROM AUTHOR]

Locust is the main pest endangering Chinese agriculture and even global agriculture. Therefore, the development of an efficient and real-time locust monitoring technology is of great significance to the prevention and management of locust disasters. Video monitoring technology has been widely used in locust monitoring, but the different postures of locusts in the field and the problem of plant shelter pose great challenges to accurate locust monitoring. In this paper, taking a 5-year-old migratory locust as the research object, video target detection based on the MOG2-YOLOv4 network is proposed to address the problem of video frame recognition failure caused by different postures and partial occlusion during locust movement. First, the frame compensation algorithm is used to identify locusts with different postures; then the background separation algorithm (MOG2) is used to extract the spatio-temporal features of the next and previous frames of the video, and the combination of the MOG2 algorithm and YOLOv4 algorithm to extract the static features of locusts in the video can improve the detection accuracy. Experimental results show that the average detection accuracy of the MOG2-YOLOv4 model is 82.33% (8.17% higher than that of YOLOv4), and the F-mean is 89.37% (4.76% higher). Therefore, this method has a good effect on the identification of East Asian migratory locusts, particularly under occlusion and motion blur conditions; it achieves accurate monitoring of the occurrence of locust plagues, which is of great significance to the prevention and control of locust plagues. [ABSTRACT FROM AUTHOR]

Chemoreception plays a crucial role in the reproduction and survival of insects, which often rely on their sense of smell and taste to find partners, suitable habitats, and food sources, and to avoid predators and noxious substances. There is a substantial body of work investigating the chemoreception and chemical ecology of Diptera (flies) and Lepidoptera (moths and butterflies); but less is known about the Orthoptera (grasshoppers, locusts, crickets, and wēta). Within the Orthoptera, the family Acrididae contains about 6700 species of short-horned grasshoppers. Grasshoppers are fascinating organisms to study due to their significant taxonomic and ecological divergence, however, most chemoreception and chemical ecology studies have focused on locusts because they are agricultural pests (e.g., Schistocerca gregaria and Locusta migratoria). Here we review studies of chemosensory systems and chemical ecology of all short-horned grasshoppers. Applications of genome editing tools and entomopathogenic microorganism to control locusts in association with their chemical ecology are also discussed. Finally, we identify gaps in the current knowledge and suggest topics of interest for future studies. [ABSTRACT FROM AUTHOR]

The vacuolar‐type H+‐ATPase (V‐ATPase) is an ATP‐dependent proton pump, which regulates various cellular processes. To date, most functional studies on V‐ATPases of insects have focused on subunits of the V1 complex, and there is little information on the VO genes. In this study, two cDNA sequences of LmV‐ATPase a were identified in Locusta migratoria. RT‐qPCR analysis revealed that LmV‐ATPase a1 and LmV‐ATPase a2 are differentially expressed in various tissues and developmental stages. Injection of dsRNA for the common region of LmV‐ATPase a1 and LmV‐ATPase a2 into third‐instar nymphs resulted in a significant suppression of LmV‐ATPase a. The injected nymphs ceased feeding, lost body weight and finally died at a mortality of 98.6%. Furthermore, aberrations of midgut epithelial cells, the accumulation of electron‐lucent vesicles in the cytoplasm, and a partially damaged brush border were observed in dsLmV‐ATPase a‐injected nymphs using transmission electron microscopy. Especially, the mRNA level of wingles, and notch genes were dramatically down‐regulated in the dsLmV‐ATPase a‐injected nymphs. Taken together, our results suggest that LmV‐ATPase a is required for survival and midgut development of L. migratoria. Hence, this gene could be a good target for RNAi‐based control against locusts. [ABSTRACT FROM AUTHOR]

Locusta migratoria is a potential alternative food and animal feed additive in South Korea and has already been registered in the European Union. We investigated the optimal conditions to improve hatchability of L. migratoria eggs under varying hatching conditions for improved artificial rearing. The parameters such as temperature, photoperiod, illuminance, or relative humidity were altered, while the other factors were kept constant. Among the four different temperature treatments (25, 27, 30, and 33°C), the 33°C temperature showed the highest total hatching rate of 85.6% at days 8–12 after oviposition. For photoperiod, hatchability was the highest (81.2%) at 9 L/15D, followed by 80.0% at 12 L/12D, and 72.6% at 15 L/9D. Under illuminance conditions of 600, 1,800, and 3,500 lux, 3,500 lux displayed the highest total hatching rate of 76.1% at days 7–11 after oviposition. Among the relative humidity (RH) levels of 50%, 65%, and 80%, 65% RH provided the highest hatching rate of 86.4% at days 8–13 post‐oviposition. In short, the most effective conditions for hatchability were 33°C, 9 L/15D, 65% RH, and 3,500 lux. Under these conditions, the hatching rate increased significantly to 98.8%. Application of these conditions will contribute to improve hatchability, which will be necessary for industrialization of L. migratoria. [ABSTRACT FROM AUTHOR]

Locusta migratoria apolipophorin III (apoLp-III) possesses the ability to exist as a water soluble amphipathic α-helix bundle and a lipid surface seeking apolipoprotein. The intrinsic ability of apoLp-III to transform phospholipid vesicles into reconstituted discoidal high-density lipoproteins (rHDL) has led to myriad applications. To improve the yield of recombinant apoLp-III, studies were performed in a bioreactor. Induction of apoLp-III expression generated a protein product that is secreted from E. coli into the culture medium. Interaction of apoLp-III with gas and liquid components in media produced large quantities of thick foam. A continuous foam fractionation process yielded a foamate containing apoLp-III as the sole major protein component. The yield of recombinant apoLp-III was ~0.2 g / liter bacterial culture. Mass spectrometry analysis verified the identity of the target protein and indicated no modifications or changes to apoLp-III occurred as a result of foam fractionation. The functional ability of apoLp-III to induce rHDL formation was evaluated by incubating foam fractionated apoLp-III with phosphatidylcholine vesicles. FPLC size exclusion chromatography revealed a single major population of particles in the size range of rHDL. The results described offer a novel approach to bioreactor-based apoLp-III production that takes advantage of its intrinsic biosurfactant properties. • Apolipophorin III (apoLp-III) is a apolipoprotein with biosurfactant properties. • Recombinant apoLp-III with a pelB leader sequence is secreted from E. coli. • In a bioreactor, apoLp-III combines with gas and liquid in media to produce foam. • Foam fractionation can be used to streamline downstream processing of apoLp-III. • ApoLp-III has numerous biotechnology applications as a nanodisks scaffold. [ABSTRACT FROM AUTHOR]

Flight ability is essential for the enormous diversity and evolutionary success of insects. The migratory locusts exhibit flight capacity plasticity in gregarious and solitary individuals closely linked with different density experiences. However, the differential mechanisms underlying flight traits of locusts are largely unexplored. Here, we investigated the variation of flight capacity by using behavioral, physiological, and multiomics approaches. Behavioral assays showed that solitary locusts possess high initial flight speeds and short-term flight, whereas gregarious locusts can fly for a longer distance at a relatively lower speed. Metabolome-transcriptome analysis revealed that solitary locusts have more active flight muscle energy metabolism than gregarious locusts, whereas gregarious locusts show less evidence of reactive oxygen species production during flight. The repression of metabolic activity by RNA interference markedly reduced the initial flight speed of solitary locusts. Elevating the oxidative stress by paraquat injection remarkably inhibited the long-distance flight of gregarious locusts. In respective crowding and isolation treatments, energy metabolic profiles and flight traits of solitary and gregarious locusts were reversed, indicating that the differentiation of flight capacity depended on density and can be reshaped rapidly. The density-dependent flight traits of locusts were attributed to the plasticity of energy metabolism and degree of oxidative stress production but not energy storage. The findings provided insights into the mechanism underlying the trade-off between velocity and sustainability in animal locomotion and movement. [ABSTRACT FROM AUTHOR]

Body color in insects changes according to the living environment and physiological stresses possibly involved in endocrine factors. To date, 3 predominant bioactive peptides, Corazonin, Elevenin, and pigment-dispersing factor (PDF), have been illuminated to be involved in the body color in insects and crustaceans. Here, we examined the possibilities that these 3 factors would contribute to body color changes via melanization in the two-spotted cricket, Gryllus bimaculatus, whose body color changes according to population density drastically. Quantitative analyses revealed the higher transcriptional levels of Corazonin and Elevenin in the crowded-conditioned crickets, whereas the transcriptional level of PDF was higher in the isolated-conditioned crickets. However, the body color was not changed by knockdown of Corazonin, Elevenin, and PDF by RNA interference. The present data indicated that coloration mechanisms in G. bimaculatus is differently controlled from the previous observation in Locusta migratoria, a closely related orthopteran species. [ABSTRACT FROM AUTHOR]

Among insects orders, Blattodea and Orthoptera are characteristic with their high significance to human habitation, as posing medical and agricultural problems. Representatives of Blattodea have an important role as carriers of a number of infectious diseases in humans and animals, and are directly related to human life and activities. On the other hand Orthoptera are very significant as agricultural pests that cause great damage to plants. The study of the mechanisms of immune defense and the processes related to the response against pathogenic infections in these two orders is of interest in order to more fully clarify the possibilities for management and control of their populations. This review summarizes the information on the defense mechanisms (hemocytes, antimicrobial peptides, pathogen recognition, signaling patways, immune and antiviral responses) studied in representatives of these two orders. The list includes 30 species of cockroaches and termites and 59 orthopteran species, and focuses on species with medical significance (Periplaneta americana, Blattella germanica) and insect pests for agriculture such as Locusta migratoria and Schistocerca gregaria. [ABSTRACT FROM AUTHOR]

The majority of long noncoding RNAs (lncRNAs) contain transposable elements (TEs). PAHAL, a nuclearretained lncRNA that is inserted by a Gypsy retrotransposon, has been shown to be a vital regulator of phenylalanine hydroxylase (PAH) gene expression that controls dopamine biosynthesis and behavioural aggregation in the migratory locust. However, the role of the Gypsy retrotransposon in the transcriptional regulation of PAHAL remains unknown. Here, we identified a Gypsy retrotransposon (named Gypsy element) as an inverted long terminal repeat located in the 3' end of PAHAL, representing a feature shared by many other lncRNAs in the locust genome. The embedded Gypsy element contains a RNA nuclear localization signal motif, which promotes the stable accumulation of PAHAL in the nucleus. The Gypsy element also provides high-affinity SRSF2 binding sites for PAHAL that induce the recruitment of SRSF2, resulting in the PAHAL-mediated transcriptional activation of PAH. Thus, our data demonstrate that TEs provide discrete functional domains for lncRNA organization and highlight the contribution of TEs to the regulatory significance of lncRNAs. [ABSTRACT FROM AUTHOR]

Background: The preponderant use of wireless telecommunication in the twenty-first century has enabled ease and efficient communication and a pervasive occurrence of electromagnetic fields (EMFs) that has significantly impacted the ecosystem. This study looks at the effect of radiations from wireless telecommunication EMF on the distribution, diversity and abundance of some insects in Nigeria. The study was undertaken in Ilorin, Kwara State, which is located in the Guinea Savannah belt of Nigeria. The chosen choice of study area was one with a telecommunication mast devoid of residential and human interference within a 10 km radius. Five sampling stations were selected around the mast and a control station. EMR intensity levels and pollinating insect number were monitored daily for 22 weeks using an acoustimeter and malaise traps. Collected insects were identified morphologically using appropriate keys. Results: The mean electromagnetic radiation (EMR) intensity was significantly (P < 0.05) highest (1.58 ± 1.52 V/m) at sampling station B, and there was an increase in EMR intensity as the radius reduced around the mast. A total of 1878 insects were recovered from the study with the dominant species in terms of abundance of insects collected from the study being Musca domestica (0.39) followed by Apis mellifera (0.31) and Locusta migratoria (0.30), while the least dominant species Tetramorium caespitum (0.23). Conclusions: Indeed, EMR intensity has an effect on the distribution, diversity and abundance of insects and there is a need to reduce the number of masts in use in the environment by encouraging telecommunication service providers to jointly use the same mast in an area for broadcast. [ABSTRACT FROM AUTHOR]

Insect development is intricately governed by hormonal signaling pathways, yet the pivotal upstream regulator that potentiates hormone activation remains largely elusive. The migratory locust, Locusta migratoria , exhibits population density-dependent phenotypic plasticity, encompassing traits such as flight capability, body coloration, and behavior. In this study, we elucidated a negative correlation between population density and ontogenetic development during the nymphal stage of locusts. We found that the level of density influences the developmental trajectory by modulating transcript abundance within the ecdysone signaling pathway, with knockdown of the prothoracicotropic hormone (PTTH) resulting in developmental delay. Transcriptomic analysis of locust brains across solitary and gregarious phases revealed significant differential expression of genes involved in various pathways, including protein synthesis, energy metabolism, hormonal regulation, and immunity. Notably, knockdown experiments targeting two energy regulators, adipokinetic hormone (AKH) and insulin-like polypeptide 1 ( ilp1 ), failed to elicit changes in the developmental process in solitary locusts. However, knockdown of immunoglobulin ( IG ) significantly shortened the developmental time in higher-density populations. Collectively, our findings underscore the regulatory role of population density in determining developmental duration and suggest that an immune-related gene contributes to the observed differences in developmental patterns.

OdTx12, a beta excitatory toxin from Odontobothus doriae had previously been identified and characterized. It had been shown that OdTx12 causes significant lethal effects on insects by injection but does not show any toxicity on mice. Due to the natural ineffectiveness of scorpion toxins to act as oral toxins, OdTx12 was fused to Galanthus nivalis agglutinin (GNA), a protein with the potential to cross the insect gut. The sequence of OdTx1 2/GNA gene was chemically synthesized, cloned in Escherichia coli , and expressed. The effect of the purified fusion protein (OdTx12/GNA) was assessed on the insect and mammalian cell lines, insect larvae and mice. Toxicity assay on insect cell culture (SF9 cell line) showed comparable toxicity between OdTx12 and OdTx12/GNA (LD50 of 0.0030 and 0.0048 μM, respectively). Also very similar mortality rates were observed by injecting OdTx12 and OdTx12/GNA to Locusta migratoria and Tenebrio molitor. Oral administration of OdTx12/GNA, after five days of feeding, resulted in 96.6% and 98.3% mortality of L. migratoria and T. molitor larvae with an LC50 of 0.69 and 0.43 nmol/g of insect food, respectively, while OdTx12 alone did not cause any toxic effects on the larvae orally, suggesting the role of GNA in delivering the toxin to the insect's haemolymph. No toxicity or mortality was observed after toxicity testing of OdTx12/GNA on a mammalian cell line (HEP-2) or any mortality in vivo, by testing the protein in the laboratory mouse. Herein, we demonstrated that the fusion protein OdTx12/GNA could be considered an effective toxin for the biological control of insects. [Display omitted] • OdTx12, a toxin from Odontobothus doriae scorpion was recombinantly fused to the snowdrop lectin (GNA). • The fusion protein (OdTx12/GNA) and OdTx12 showed similar toxic effects on the model insects by injection. • OdTx12/GNA caused high mortality in the insects orally but OdTx12 itself showed no toxicity effects by the same route. • GNA caused the toxin to pass through the gut epithelium and reach the insect haemolymph. • OdTx12/GNA may be considered as a biological insecticide candidate. [ABSTRACT FROM AUTHOR]

Locusts are advantageous organisms to elucidate mechanisms of olfactory coding at the systems level. Sensory input is provided by the olfactory receptor neurons of the antenna, which send their axons into the antennal lobe. So far, cellular properties of neurons isolated from the circuitry of the olfactory system, such as transmitter-induced calcium responses, have not been studied. Biochemical and immunocytochemical investigations have provided evidence for acetylcholine as classical transmitter of olfactory receptor neurons. Here, we characterize cell cultured projection and local interneurons of the antennal lobe by cytosolic calcium imaging to cholinergic stimulation. We bulk loaded the indicator dye Cal-520 AM in dissociated culture and recorded calcium transients after applying cholinergic agonists and antagonists. The majority of projection and local neurons respond with increases in calcium levels to activation of both nicotinic and muscarinic receptors. In local interneurons, we reveal interactions lasting over minutes between intracellular signaling pathways, mediated by muscarinic and nicotinic receptor stimulation. The present investigation is pioneer in showing that Cal-520 AM readily loads Locusta migratoria neurons, making it a valuable tool for future research in locust neurophysiology, neuropharmacology, and neurodevelopment. [ABSTRACT FROM AUTHOR]

Background: The zinc-finger transcription factor Krüppel-homolog 1 (Kr-h1) exerts a dual regulatory role during insect development by preventing precocious larval/nymphal metamorphosis and in stimulating aspects of adult reproduction such as vitellogenesis. However, how Kr-h1 functions both as a transcriptional repressor in juvenile metamorphosis and an activator in adult reproduction remains elusive. Here, we use the insect Locusta migratoria to dissect the molecular mechanism by which Kr-h1 functions as activator and repressor at these distinct developmental stages. Results: We report that the kinase PKCα triggers Kr-h1 phosphorylation at the amino acid residue Ser154, a step essential for its dual functions. During juvenile stage, phosphorylated Kr-h1 recruits a corepressor, C-terminal binding protein (CtBP). The complex of phosphorylated Kr-h1 and CtBP represses the transcription of Ecdysone induced protein 93F (E93) and consequently prevents the juvenile-to-adult transition. In adult insects, phosphorylated Kr-h1 recruits a coactivator, CREB-binding protein (CBP), and promotes vitellogenesis by inducing the expression of Ribosomal protein L36. Furthermore, Kr-h1 phosphorylation with the concomitant inhibition of E93 transcription is evolutionarily conserved across insect orders. Conclusion: Our results suggest that Kr-h1 phosphorylation is indispensable for the recruitment of transcriptional cofactors, and for its anti-metamorphic and vitellogenic actions in insects. Our data shed new light on the understanding of Kr-h1 regulation and function in JH-regulated insect metamorphosis and reproduction. [ABSTRACT FROM AUTHOR]

Chitin deacetylases (CDAs, including CDA1 and CDA2) are considered key enzymes for body cuticle formation and tracheal morphogenesis in various insect species. However, their functions in the formation of the cuticular intima of the foregut and hindgut are unclear. Here, we investigated the roles of their respective genes LmCDA1 and LmCDA2 in this process, in the hemimetabolous insect Locusta migratoria. Transcripts of LmCDA1 and LmCDA2 were highly expressed both before and after molting in the foregut. In the hindgut, their expression was high only before molting. In both the foregut and hindgut, LmCDA1 protein was localized in the basal half of the chitin matrix (procuticle), whereas LmCDA2 was detected in the upper half of the procuticle. Knockdown of LmCDA1 by RNA interference (RNAi) in 5th‐instar nymphs caused no visible defects of the hindgut cuticle. By contrast, the chitinous lamellae of the cuticular intima in the foregut of knockdown animals were less compact than in control animals. RNAi against LmCDA2 led to thickening of both the foregut and hindgut cuticles, with a greater number of thinner laminae than in the respective control cuticles. Taken together, our results show that LmCDA1 and LmCDA2 have distinct, but overlapping, functions in chitin organization in the foregut cuticle. However, in the hindgut, this process seems independent of LmCDA1 activity but requires LmCDA2 function. Thus, the CDAs reflect tissue‐specific differences in cuticular organization and function, which need further detailed molecular and histological analyses for full comprehension. [ABSTRACT FROM AUTHOR]

The genus Weissella is attracting an increasing amount of attention because of its multiple functions and probiotic potential. In particular, the species Weissella confusa is known to have great potential in industrial applications and exhibits numerous biological functions. However, the knowledge on this bacterium in insects is not investigated. Here, we isolated and identified W. confusa as the dominant lactic acid bacteria in the gut of the migratory locust. We named this strain W. confusa LM1, which is the first genome of an insect-derived W. confusa strain with one complete chromosome and one complete plasmid. Among all W. confusa strains, W. confusa LM1 had the largest genome. Its genome was the closest to that of W. confusa 1001271B_151109_G12, a strain from human feces. Our results provided accurate evolutionary relationships of known Weissella species and W. confusa strains. Based on genomic analysis, the pan-genome of W. confusa is in an open state. Most strains of W. confusa had the unique genes, indicating that these strains can adapt to different ecological niches and organisms. However, the variation of strain-specific genes did represent significant correlations with their hosts and ecological niches. These strains were predicted to have low potential to produce secondary metabolites. Furthermore, no antibiotic resistance genes were identified. At the same time, virulence factors associated with toxin production and secretion system were not found, indicating that W. confusa strains were not sufficient to perform virulence. Our study facilitated the discovery of the functions of W. confusa LM1 in locust biology and their potential application to locust management. [ABSTRACT FROM AUTHOR]

Vitellogenin receptor (VgR) plays a pivotal role in ovarian vitellogenin (Vg) uptake and vertical transmission of pathogenic microbes and Wolbachia symbionts. However, the regulatory mechanisms of VgR action as an endocytic receptor and translocation from oocyte cytoplasm to the membrane remain poorly understood. Here, by using the migratory locust Locusta migratoria as a model system, we report that juvenile hormone (JH) promotes VgR phosphorylation at Ser1361 in the second EGF-precursor homology domain. A signaling cascade including GPCR, PLC, extracellular calcium, and PKC-ι is involved in JH-stimulated VgR phosphorylation. This posttranslational regulation is a prerequisite for VgR binding to Vg on the external surface of the oocyte membrane and subsequent VgR/Vg endocytosis. Acidification, a condition in endosomes, induces VgR dephosphorylation along with the dissociation of Vg from VgR. Phosphorylation modification is also required for VgR recycling from oocyte cytoplasm to the membrane. Additionally, VgR phosphorylation and its requirement for Vg uptake and VgR recycling are evolutionarily conserved in other representative insects including the cockroach Periplaneta americana and the cotton bollworm Helicoverpa armigera. This study fills an important knowledge gap of low-density lipoprotein receptors in posttranslational regulation, endocytosis, and intracellular recycling. [ABSTRACT FROM AUTHOR]

Cytochrome P450 monooxygenases (CYPs) play essential physiological functions in insects. CYP303A1 is highly conserved in insect species studied to date, and shows an indispensable role for adult eclosion in both Locusta migratoria and Drosophila melanogaster. However, how CYP303A1 is regulated to control insect developmental processes remains uninvestigated. In this study, we discovered functional binding sites for miR‐184 in the coding sequence of LmCYP303A1. The luciferase reporter assay showed that miR‐184 could target LmCYP303A1 and regulate its expression in vitro. Furthermore, overexpression of miR‐184 through microinjection of agomir to locusts reduced the transcripts of LmCYP303A1 and led to abnormal molting, which is similar to the phenotype of silencing LmCYP303A1 by direct injection of dsLmCYP303A1 to locusts. Meanwhile, down‐regulation of miR‐184 by injection of antagomir increased the LmCYP303A1 transcript and caused molting defects. These findings suggested that miR‐184 could target LmCYP303A1 to regulate the molting process in L. migratoria, which might be considered as a novel target for pest control. [ABSTRACT FROM AUTHOR]

Trichomes function in plant defenses against biotic and abiotic stresses; examination of glabrous lines, which lack trichomes, has revealed key aspects of trichome development and function. Tests of allelism in 51 glabrous rice (Oryza sativa) accessions collected worldwide identified OsSPL10 and OsWOX3B as regulators of trichome development in rice. Here, we report that OsSPL10 acts as a transcriptional regulator controlling trichome development. Haplotype and transient expression analyses revealed that variation in the approximately 700‐bp OsSPL10 promoter region is the primary cause of the glabrous phenotype in the indica cultivar WD‐17993. Disruption of OsSPL10 by genome editing decreased leaf trichome density and length in the NIL‐HL6 background. Plants with genotype OsSPL10WD‐17993/HL6 generated by crossing WD‐17993 with NIL‐HL6 also had fewer trichomes in the glumes. HAIRY LEAF6 (HL6) encodes another transcription factor that regulates trichome initiation and elongation, and OsSPL10 directly binds to the HL6 promoter to regulate its expression. Moreover, the transcript levels of auxin‐related genes, such as OsYUCCA5 and OsPIN‐FORMED1b, were altered in OsSPL10 overexpression and RNAi transgenic lines. Feeding tests using locusts (Locusta migratoria) demonstrated that non‐glandular trichomes affect feeding by this herbivore. Our findings provide a molecular framework for trichome development and an ecological perspective on trichome functions. [ABSTRACT FROM AUTHOR]

Abstract Following a request from the European Commission, the EFSA Panel on Nutrition, Novel Food and Food Allergens (NDA) was asked to deliver an opinion on the safety of frozen and dried formulations from migratory locust (Locusta migratoria) as a novel food pursuant to Regulation (EU) 2015/2283. The term migratory locust refers to the adult of the insect species Locusta migratoria. The NF is proposed in three formulations i) frozen without legs and wings; ii) dried without legs and wings; iii) ground with legs and wings. The main components of the NF are protein, fat and fibre (chitin) in the dried form of the NF, and water, protein, fat and fibre (chitin) in the frozen form of the NF. The Panel notes that the concentration of contaminants in the NF depends on the occurrence levels of these substances in the insect feed. The Panel notes that there are no safety concerns regarding the stability of the NF if the NF complies with the proposed specification limits during its entire shelf‐life. The NF has a high protein content, although the true protein levels in the NF are overestimated when using the nitrogen‐to‐protein conversion factor of 6.25, due to the presence of non‐protein nitrogen from chitin. The applicant proposed to use the NF as frozen, dried and ground in the form of snack, and as a food ingredient in a number of food products. The target population proposed by the applicant is the general population. The Panel notes that considering the composition of the NF and the proposed conditions of use, the consumption of the NF is not nutritionally disadvantageous. The submitted history of use and toxicity studies from literature did not raise safety concerns. The Panel considers that the consumption of the NF might trigger primary sensitisation to L. migratoria proteins and may cause allergic reactions in subjects with allergy to crustaceans, mites and molluscs. Additionally, allergens from the feed may end up in the NF. The Panel concludes that the NF is safe under the proposed uses and use levels.