摘要: Species distributed across wide elevational gradients are likely to experience local thermal adaptation and exhibit high thermal plasticity, as these gradients are characterised by steep environmental changes over short geographic distances (i.e., strong selection differentials). The prevalence of adaptive intraspecific variation in thermal tolerance with elevation remains unclear, however, particularly in freshwater taxa. We explored variation in upper and lower thermal limits and acclimation capacity among Iberian populations of adults of the widespread water beetle Agabus bipustulatus (Dytiscidae) across a 2000 m elevational gradient, from lowland to alpine areas. Since mean and extreme temperatures decline with elevation, we predicted that populations at higher elevations will show lower heat tolerance and higher cold tolerance than lowland ones. We also explored whether acclimation capacity is positively related with climatic variability across elevations. We found significant variation in thermal limits between populations of A. bipustulatus, but no evidence of local adaptation to different thermal conditions across the altitudinal gradient, as relationships between thermal limits and elevation or climatic variables were largely nonsignificant. Furthermore, plasticities of both upper and lower thermal limits were consistently low in all populations. These results suggest thermal niche conservatism in this species, likely due to gene flow counteracting the effects of divergent selection, or adaptations in other traits that buffer exposure to climate extremes. The limited adaptive potential and plasticity of thermal tolerance observed in A. bipustulatus suggest that even generalist species, distributed across wide environmental gradients, may have limited resilience to global warming.

摘要: Juvenile hormones (JHs) play a crucial role in regulating development and reproduction in insects. Most insects predominantly synthesize JH III, which typically involves esterification followed by epoxidation, lepidopteran insects use a pathway of epoxidation followed by esterification. Although hemipteran insects have JH III and JH skipped bisepoxide III (JH SB3), the synthesis pathway and key epoxidases remain unclear. This study was conducted on Aphis craccivora, and demonstrated that corpora allata, microsomes, Ac-CYP15C1, and Ac-JHAMT catalyze JH III production in vitro, establishing the pathway of epoxidation followed by esterification. These findings were further confirmed through RNA interference and molecular docking. The presence of JH III and JH SB3 in A. craccivora was identified, and their synthesis pathway was elucidated as follows: Ac-CYP15C1 oxidizes farnesic acid to JH A, followed by methylation to JH III by Ac-JHAMT, possibly providing an epoxidation site on the second carbon for JH SB3. This alteration may significantly contribute to the differentiation and functional diversification of JH types in insects.

摘要: In the organisms with XX/XY sex chromosomes, Y chromosome is unique to males and plays an important role in male reproductive development. The study of Y chromosome genes will contribute to the development of pest genetic prevention and control technology. In this study, we identified 9 Y chromosome genes in Zeugodacus tau (Diptera: Tephritidae), including gene 16222. Protein structure analysis showed that 16222 was highly similar to odorant binding protein, and thus gene 16222 was named obp-Y. Obp-Y knockout (KO) significantly reduced hatching rate of offspring. Sperm detection results showed that obp-Y KO did not affect sperm number in the testes or sperm transfer during mating. We further examined the storage of sperms in females, and found that sperms in females mating with wild-type males began to transfer from spermathecal ducts to the spermathecae at hour 0 after the end of mating (AEM), and at 0-24 h AEM, the sperm count in the spermathecae gradually increased. However, no sperms were observed in spermathecae of females mating with mutant males at hours 0, 4, 8, 24 and 48 AEM. In summary, this study revealed that Y chromosome gene obp-Y was necessary for the storage of sperms in females. Our findings not only provide theoretical basis for elucidating the function of the Y chromosome, but also offer a molecular target for the genetic control over Z. tau.

摘要: No mechanoreceptor potential C (NompC) is a major mechanotransduction channel with an important role in sensing of external mechanical stimuli by insects, which help these organisms to avoid injury and adapt to environmental changes. To explore the biological functions of NompC in Bactrocera dorsalis, a notorious agricultural pest, we successfully generated NompC knockout strains using clustered regularly interspaced small palindromic repeats (CRISPR) / CRISPR-associated nuclease 9 (Cas9) technology. BdorNompC knockout led to an adult lethal phenotype, with approximately 100% mortality at 3 d after eclosion. Morphological observation revealed that the legs and wings of BdorNompC knockout insects were deformed, while behavioral assays showed that the locomotion was impaired in both adults and larvae, relative to that of the wild-type strain. Moreover, BdorNompC knockout reduced gentle-touch response in larvae. These results suggest that BdorNompC is critical for B. dorsalis survival, and that this mechanosensation channel represents a potential new target for pest control agents. Our findings also represent novel evidence indicating that insect NompC is involved in modulating adult wing and leg morphology.

摘要: The escalating severity of Bombyx mori nuclear polyhedrosis virus (BmNPV) infections poses significant challenges to the silkworm industry, especially when massive production shifts occur from the eastern regions to western regions with lower labor costs. Education and experience levels are different and disease control is badly needed. To solve the problems, we have developed an innovative CRISPR/Cas9 system specifically targeting BmNPV to enhance viral resistance. For the system, we selected BmNPV genes linked to virus replication and proliferation as targets, designing 2 sites for each gene. Mutating the target sequence renders the system incapable of efficiently cleaving the virus genome, hence decreasing cleavage efficiency. We conducted a search for NGG or CCN target sequences in the BmNPV genome, excluding non-recurring and potential targets in the B. mori genome. We successfully identified 2 distinct target sequences in the BmNPV genome-one being repeated 12 times and the other three times. These sequences lead to fragmentation of virus genome into multiple large segments that are difficult to repair. Transgenic silkworms demonstrate robust resistance to viruses, significantly boosting their survival rates compared with wild-type silkworms under various virus infection concentrations. Our system efficiently targets dozens of viral genomes with just 2 sequences, minimizing transposable elements while ensuring cutting effectiveness. This marks a pioneering advancement by using repetitive elements within the virus genome for targeted CRISPR cleavage, aiming for antiviral effects through genome fragmentation rather than disrupting essential viral genes. Our research introduces innovative concepts to CRISPR antiviral investigations and shows promise for the practical application of gene editing in industrial silkworm strains.

摘要: In this review, we show that predatory ants have a wide range of foraging behavior, something expected given their phylogenetic distance and the great variation in their colony size, life histories, and nesting habitats as well as prey diversity. Most ants are central-place foragers that detect prey using vision and olfaction. Ground-dwelling species can forage solitarily, the ancestral form, but generally recruit nestmates to retrieve large prey or a group of prey. Typically, ants are omnivorous, but some species are strict predators preying on detritivorous invertebrates or arthropod eggs, while those specialized on termites or other ants often have scouts that localize their target and then trigger a raid. They can use compounds that ease this task, including chemical insignificance, mimicry, and venoms triggering submissive behavior. Army ants include 8 Dorylinae and some species from other subfamilies, all having wingless queens and forming raids. Dorylinae from the Old World migrate irregularly to new nesting sites. The foraging of most New World species that prey on the brood of other ants is regulated by their biological cycle that alternates between a nomadic phase when the colony relocates between different places and a stationary phase when the colony stays in a bivouac constituting a central place. Among arboreal ants, dominant species forage in groups, detecting prey visually, but can use vibrations, particularly when associated with myrmecophytes. Some species of the genera Allomerus and Azteca use fungi to build a gallery-shaped trap with small holes under which they hide to ambush prey.

摘要: Insulin-like peptides (ILPs) act as crucial reproductive neuropeptides in insects, regulating insect reproduction through the insulin signaling pathway (ISP). Our previous studies have found that the sublethal concentrations (LC1 and LC10) of lambda-cyhalothrin (lambda Cy) could induce severe reproductive toxicity in the lacewing, Chrysoperla sinica (Tjeder), but the toxicological mechanism remains unclear. This study discovered that lambda Cy could inhibit CsILP transcription, leading to a decrease in insulin content and downregulation of C. sinica insulin receptor (CsInR) and C. sinica forkhead box O (CsFOXO) expression in ISP. Interference with CsILP expression resulted in downregulation of C. sinica vitellogenin (CsVg) and decreasing fecundity, while exogenous injection of bovine insulin promoted upregulation of CsVg expression and facilitated reproduction in female adults of C. sinica. Meanwhile, interference with FOXO of ILP downstream transcription factor could lead to downregulation of CsVg, hindering ovarian development and resulting in a decrease in egg production. However, exogenous injection of bovine insulin could remedy the effects caused by FOXO interference. In addition, ILP mediates juvenile hormone and 20-hydroxyecdysone biosynthesis by acting on their synthetic regulatory enzymes and influences the signal transduction of the 2 reproductive endocrine hormones, thereby regulating the reproductive endocrine environment in C. sinica. In conclusion, lambda Cy inhibits CsILP expression, leading to disorder of ISP, leading to the reduced fecundity of C. sinica.

摘要: In addition to preventing precocious larval metamorphosis, juvenile hormone (JH), synthesized in corpora allata (CA), is known to stimulate female reproduction of insects. JH titer is extremely low or absent during metamorphosis, but thereafter rapidly increases in the previtellogenic stage and rises to a peak in the vitellogenic phase. However, the mechanisms underlying the biosynthesis of high levels of JH in adults remain unclear. We found in this study that 12 genes involved in JH synthesis pathway were highly expressed in the CA of adult locusts. By transcriptome analysis and quantitative real-time - polymerase chain reaction validation, a total of 106 evolutionary conserved micro RNAs (miRNAs) and 163 species-specific miRNAs were identified in locust CA. Dual-luciferase assay revealed that 17 miRNAs bound to 10 JH synthesis genes (JHSGs) and downregulated their expression. These miRNAs were expressed in low levels during vitellogenic stage, which was oppositive from that of targeting JHSGs. Six miRNAs including miR-971-3p, miR-31a, miR-9-5p, miR-1-3p, miR-315, and miR-282 were selected for function study. Co-application of agomiRs resulted in significantly decreased levels of targeting JHSGs, accompanied by significantly reduced vitellogenin expression as well as arrested ovarian development. The data suggest that multiple miRNAs expressed synchronously at low levels in the vitellogenic phase, thereby ensuring the high levels of JHSG expression to facilitate JH biosynthesis required for JH-dependent female reproduction. The findings provide important information for deciphering miRNA-messenger RNA modules for JH biosynthesis as well as JH regulation of insect metamorphosis and reproduction.

摘要: Hemiptera is one of the most significant orders of insect pests, including whiteflies, true bugs, aphids, planthoppers, psyllids, and so forth, which have led to substantial economic losses in agricultural industries and have significantly affected food yields through their ability to suck the phloem sap of crops and transmit numerous bacterial and viral pathogens. Therefore, explorations of pest-specific, eco-friendly and easy-to-adopt technologies for hemipteran pest control are urgently needed. To the best of our knowledge, microRNAs (miRNAs), which are endogenous non-coding small RNAs approximately 22 nucleotides in length, are involved in regulating gene expression via the direct recognition and binding of the 3 '-untranslated region (3 '-UTR) of target messenger RNAs (mRNAs) or by acting as a center of a competitive endogenous RNA (ceRNA) network at the post-transcriptional level. This review systematically outlines the characterization and functional investigation of the miRNA biogenesis pathway in hemipteran pests, such as whiteflies, true bugs, aphids and planthoppers. In addition, we explored the results of small RNA sequencing and functional observations of miRNAs in these pests, and the results suggest that the numerous miRNAs obtained and annotated via high-throughput sequencing technology and bioinformatic analyses contribute to molting development, fitness, wing polyphenism, symbiont interactions and insecticide resistance in hemipteran pests. Finally, we summarize current advances and propose a framework for future research to extend the current data and address potential limitations in the investigation and application of hemipteran miRNAs.

摘要: Previous studies have shown oviposition deterring properties of 8 coconut free fatty acid (CFFA) compounds on fruit flies with different key deterrent components for different species. Here we evaluated oviposition deterrence of CFFA using laboratory 2-choice bioassays against Zeugodacus cucurbitae, determined key-bioactive deterrent compounds, and evaluated their behavioral mode. Unlike other reported fruit fly species, CFFA mixture increased Z. cucurbitae oviposition when directly applied on an oviposition substrate. When tested individually in subsequent tests, 4 compounds (caprylic, capric, oleic, and linoleic acids) significantly reduced the oviposition (negative-compounds), 1 compound (stearic acid) had no effect (neutral-compound), and 3 compounds (lauric, myristic, and palmitic acids) stimulated the oviposition (positive-compounds). The 4-component negative-compound blend was effective at reducing oviposition. However, adding stearic acid to the 4-component blend (5-component blend, 5c) further reduced oviposition. Adding any of the positive-compounds to the 5c resulted in loss of oviposition deterrence, suggesting the 5c as the key deterrent component blend. The blend was also effective in no-choice assays and when applied on cucumbers, a preferred host of Z. cucurbitae. When given a choice, Z. cucurbitae made 48.5% fewer visits, spent 39% less time, and oviposited 88.2% fewer eggs per min on 5c treated pumpkin agar than on control agar, suggesting that the 5c blend has both spatial repellency and contact deterrence. Given that all compounds are registered food additives and generally regarded as safe, this blend has potential application in behavioral control strategies, such as push-pull, to protect host fruit against Z. cucurbitae.