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For Selected: Download Citations EndNote Ris BibTeX Toggle Thumbnails Select Maleness-on-the-Y (MoY) orthologue is a key regulator of male sex determination in Zeugodacus cucurbitae (Diptera: Tephritidae) FAN Zi-zhen, MA Qin, MA Si-ya, CAO Feng-qin, YAN Ri-hui, LIN Xian-wu 2023, 22 (2): 505-513.   DOI: 10.1016/j.jia.2022.08.007 Abstract （844）      PDF in ScienceDirect       The initiation of sex differentiation in insects is regulated by primary sex determination signals.  In the Medfly Ceratitis capitata and other Tephritids, Maleness-on-the-Y (MoY) is the master gene for male sex determination.  However, the primary signal in Zeugodacus cucurbitae (Coquillett), a very destructive Tephritid pest across the world, remains ambiguous.  In this study, we have isolated and characterized the Medfly MoY homolog in Z. cucurbitae, ZcMoY.  ZcMOY protein shows high sequence conservation to its homologs in Bactrocera species.  ZcMoY transcription begins and peaks at very early embryonic stages and then becomes undetectable except the testes and heads of day 1 male adults.  Silencing ZcMoY in early embryos by RNAi causes abnormal external genitalia and interior reproductive organs, giving rise to intersexes and feminization of XY individuals.  The expression pattern and knockdown phenotypes of ZcMoY indicate that ZcMoY plays a key role in regulating sex determination of Z. cucurbitae males.  Our findings will help the understanding of sex determination in Z. cucurbitae and facilitate the development of genetic sexing strains in its biological control. Reference | Related Articles | Metrics Select Molecular phylogeny and identification of agromyzid leafminers in China, with a focus on the worldwide genus Liriomyza (Diptera: Agromyzidae)  LIANG Yong-xuan, DU Su-jie, ZHONG Yu-jun, WANG Qi-jing, ZHOU Qiong, WAN Fang-hao, GUO Jian-yang, LIU Wan-xue 2023, 22 (10): 3115-3134.   DOI: 10.1016/j.jia.2023.04.030 Abstract （660）      PDF in ScienceDirect       Leaf-mining flies (Diptera: Agromyzidae) are a diverse family of small-bodied insects that feed on living plant tissues as larvae.  Various species in this family are considered globally invasive and have caused great agricultural economic losses.  In China, economically important vegetable crops have been seriously damaged by these pest insects, especially by species of the genus Liriomyza.  However, these species are difficult to differentiate because of their morphological similarities, and the Chinese fauna remains poorly known.  To explore the relevant pest species in China and their phylogeny, agromyzid leafminers were collected from 2016 to 2019, and identified based on morphological characteristics and DNA barcodes.  In total, 27 species from five genera of Agromyzidae were sampled and identified, including 16 species of Liriomyza.  Both mitochondrial and nuclear genes were used to reconstruct their phylogenetic relationships and estimate the divergence time.  Highly congruent and well-supported phylogenetic trees were obtained using the Bayesian inference and maximum-likelihood methods.  This analysis revealed two main clades in Liriomyza, and clade 2 was inferred to have diverged from clade 1 approximately 27.40 million years ago (95% highest posterior density: 23.03–31.52 million years ago) in the Oligocene.  Differences were observed in the distribution patterns and host associations between the Liriomyza clades.  Clade 2 species are distributed in cool, high-latitude environments, suggesting that they may have evolved into a cool-adapted lineage. Reference | Related Articles | Metrics Select Fatty acid-binding protein gene is indispensable for molting process in Heortia vitessoides (Lepidoptera: Crambidae) YE Qing-ya, LI Zhi-xing, CHEN Qing-ling, SUN Ming-xu, YIN Ming-liang, LIN Tong 2023, 22 (2): 495-504.   DOI: 10.1016/j.jia.2022.08.003 Abstract （596）      PDF in ScienceDirect       As intracellular fatty acid (FA) carriers, FA-binding proteins (FABPs) widely participate in the absorption, transport, and metabolism of FAs.  It is a key protein in insect lipid metabolism and plays an important role in various physiological activities of insects.  An FABP gene (HvFABP) was cloned from the transcriptional library of Heortia vitessoides Moore (Lepidoptera: Crambidae), and its expression patterns were determined using reverse transcription quantitative PCR (RT-qPCR).  Stage- and tissue-specific expression profiles indicated that HvFABP highly expressed from prepupal to adult stages and in larval midgut and adult wings.  HvFABP expression may be induced through starvation, mRNA expression was downregulated at 24 and 48 h and upregulated at 72 h after starvation.  Furthermore, 20-hydroxyecdysone can induce the upregulation of its expression.  RNA interference-mediated silencing of HvFABP significantly inhibited HvFABP expression, resulting in delayed development, abnormal molting or lethal phenotypes, and a significantly reduced survival rate.  These results indicate that HvFABP plays a key role in the molting of H. vitessoides Reference | Related Articles | Metrics Select Light intensity regulates the sexual behaviors of oriental fruit fly Bactrocera dorsalis under laboratory conditions REN Cong, ZHANG Jie, YUAN Jin-xi, WU Yun-qi-qi-ge, YAN Shan-chun, LIU Wei, WANG Gui-rong 2023, 22 (9): 2772-2782.   DOI: 10.1016/j.jia.2023.04.025 Abstract （531）      PDF in ScienceDirect       The oriental fruit fly, Bactrocera dorsalis (Hendel), is a devastating pest of citrus fruits.  After successful mating, adult females insert their eggs into the ripened fruit, resulting in moldy and rotten fruit and causing great economic losses for the citrus industry.  In the field, flies initiate copulatory behaviors as twilight approaches, and decreasing light intensity in this period is the normal stimulus for copulation.  In this study, ten light intensities ranging from 0–30 000 lux were set to identify the typical intensity that strongly regulates the copulation behavior of B. dorsalis.  Three light intensities found to regulate the copulation behavior were then selected to verify their effects on adult male wing fanning and female chemotaxis towards 2,3,5-trimethylpyrazine (TMP).  At last, strong light and complete darkness were artificially combined in the lab to verify whether they could prevent copulation to inform behavioral manipulation of oriental flies in the future.  The results indicated that adult flies generally initiated copulatory behaviors at low light intensity (<1 000 lux).   Stronger light significantly prevented copulation in proportion to intensity, with nearly no copulation events initiated when light intensity was above 20 000 lux.  Both male wing fanning and female chemotaxis towards TMP were attenuated as light intensity became stronger.  However, at 10 000 lux, males still fanned their wings to a certain extent while TMP completely lost its attractiveness to females.  In the darkness, adults did not initiate any sexual behaviors, e.g., copulation, wing fanning, or chemotaxis to TMP.  One hour of strong light (10 000 lux) combined with continuous darkness completely prevented mating.  These results show that light condition is an essential factor for copulatory behaviors in the oriental fruit fly.  Researchers could thus manipulate light conditions artificially or disrupt the molecular target in flies’ light transduction pathway to develop environmentally-friendly techniques to control this pest. Reference | Related Articles | Metrics Select Brown planthopper E78 regulates moulting and ovarian development by interacting with E93 ZHENG Shi-wen, JIANG Xiao-juan, MAO Yi-wen, LI Yan, GAO Han, LIN Xin-da 2023, 22 (5): 1455-1464.   DOI: 10.1016/j.jia.2022.08.106 Abstract （446）      PDF in ScienceDirect       The brown planthopper (Nilaparvata lugens) is the main migratory pest in many rice growing areas in Asia.  E78 is a member of the nuclear hormone receptor superfamily which plays an important role in egg development and maternal regulation of early embryogenesis.  In this study, brown planthopper E78 (NlE78) was cloned, and the predicted amino acid sequence showed that it contains two conserved domains: NR-LBD and DBD.  qRT-PCR showed that the expression of NlE78 is high in the fifth instar nymphs and the ovaries of females.  After downregulation of NlE78, the rate of moulting failure (33.2%) increased significantly, and ovarian development was delayed.  However, when NlE78 was downregulated together with NlE93, the emergence rate increased significantly (78.79%), and ovarian development was similar to that when NlE78 was downregulated but not delayed.  A co-immunoprecipitation experiment showed that NlE78 interacts with NlE93, a crucial downstream transcription factor of the ecdysone signalling pathway.  Cellular localization by immunofluorescence revealed that NlE78 and NlE93 are expressed in the nucleus.  This study indicates that NlE78 regulates ovarian development and moulting, possibly through its interaction with NlE93.  This study is of great significance for the development of new pesticides and control methods based on newly discovered targets. Reference | Related Articles | Metrics Select The biosynthesis of alarm pheromone in the wheat aphid Rhopalo-siphum padi is regulated by hormones via fatty acid metabolism Chengxian Sun, Yaoguo Qin, Julian Chen, Zhengxi Li 2024, 23 (7): 2346-2361.   DOI: 10.1016/j.jia.2023.11.030 Abstract （444）      PDF in ScienceDirect       Aphids are major insect pests in agriculture and forestry worldwide. Following attacks by natural enemies, many aphids release an alarm pheromone to protect their population. In most aphids, the main component of the aphid alarm pheromone (AAP) is the sesquiterpene hydrocarbon (E)-β-farnesene (EβF). However, the mechanisms behind its biosynthesis and regulation remain poorly understood. In this study, we used the bird cherry–oat aphid Rhopalosiphum padi, which is an important wheat aphid, to investigate the regulatory mechanisms of EβF biosynthesis. Our results showed that EβF biosynthesis occurs during the mature embryo period and the molting period of the 1st- and 2nd-instar nymphs. Triglycerides provide the prerequisite material for EβF production and release. Based on transcriptome sequencing, RNAi analysis, hormone treatments, and quantitative measurements, we found that the biosynthesis of EβF utilizes acetyl coenzyme A produced from fatty acid degradation, which can be suppressed by juvenile hormone but it is promoted by 20-hydroxyecdysone through the modulation of fatty acid metabolism. This is the first systemic study on the modulation of EβF production in aphids. The results of our study provide insights into the molecular regulatory mechanisms of AAP biosynthesis, as well as valuable information for designing potential aphid control strategies. Reference | Related Articles | Metrics Select Serine protease inhibitors LmSPN2 and LmSPN3 co-regulate embryonic diapause in Locusta migratoria manilensis (Meyen) via the Toll pathway FENG Shi-qian, ZHANG Neng, CHEN Jun, ZHANG Dao-gang, ZHU Kai-hui, CAI Ni, TU Xiong-bing, ZHANG Ze-hua 2023, 22 (12): 3720-3730.   DOI: 10.1016/j.jia.2023.05.019 Abstract （435）      PDF in ScienceDirect       Female adults of the migratory locust, Locusta migratoria manilensis (Meyen), can sense seasonal photoperiod changes, which induces embryonic diapause as a key strategy to overwinter.  Serine protease inhibitor genes (SPNs) were thought to play key roles during diapause, while few SPNs were functionally characterized.  LmSPN2 was one of those genes differentially expressed between diapause and non-diapause eggs; however, its biological function remained to be explored.  So, we conducted RNAi knockdown of LmSPN2, resulting in a significant decrease of the egg diapause rate by 29.7%.  Using yeast two-hybrid assays, co-immunoprecipitation, and pull-down methods, we found an interaction between LmSPN2 and LmSPN3, which was proved to be mediated by a glutamate (E331) binding site of LmSPN2.  RNAi knockdown of LmSPN3 resulted in a significant increase in diapause rate by 14.6%, indicating an inverse function of LmSPN2 and LmSPN3 on diapause regulation.  Double knockdown of two SPN genes resulted in a 26.4% reduction in diapause rate, indicating that LmSPN2 was the dominant regulatory signal.  Moreover, we found four Toll pathway genes (easter, spätzle, pelle, and dorsal) upregulated significantly after the knockdown of LmSPN2 while downregulated after the knockdown of LmSPN3.  Therefore, we speculate that two SPNs regulate diapause through the Toll pathway.  Our results indicated that LmSPN2 positively regulates locust egg entry into diapause, while LmSPN3 is a negative regulator of embryonic commitment to diapause.  Their interaction is mediated by the binding site of E331 and influences egg diapause through the Toll pathway.  This mechanistic understanding of diapause regulation expands our understanding of insect developmental regulation and provides functional targets for developing locust management strategies. Reference | Related Articles | Metrics Select Development and formation of wing cuticle based on transcriptomic analysis in Locusta migratoria during metamorphosis Jing Zhang, Zhaochen Wu, Shuo Li, He Huang, Suning Liu, Weimin Liu, Xiaoming Zhao, Jianzhen Zhang 2024, 23 (4): 1285-1299.   DOI: 10.1016/j.jia.2023.10.022 Abstract （433）      PDF in ScienceDirect       Wings are an important flight organ of insects.  Wing development is a complex process controlled by a series of genes.  The flightless wing pad transforms into a mature wing with the function of migratory flight during the nymph-to-adult metamorphosis.  However, the mechanism of wing morphogenesis in locusts is still unclear.  This study analyzed the microstructures of the locust wing pads at pre-eclosion and the wings after eclosion and performed the comparative transcriptome analysis.  RNA-seq identified 25,334 unigenes  and 3,430 differentially expressed genes (DEGs) (1,907 up-regulated and 1,523 down-regulated).  The DEGs mainly included cuticle development (LmACPs), chitin metabolism (LmIdgf4), lipid metabolism-related genes, cell adhesion (Integrin), zinc finger transcription factors (LmSalm, LmZF593 and LmZF521), and others.  Functional analysis based on RNA interference and hematoxylin and eosin (H&E) staining showed that the three genes encoded zinc finger transcription factors are essential for forming wing cuticle and maintaining morphology in Locusta migratoria.  Finally, the study found that the LmSalm regulates the expression of LmACPs in the wing pads at pre-eclosion, and LmZF593 and LmZF521 regulate the expression of LmIntegrin/LmIdgf4/LmHMT420 in the wings after eclosion.  This study revealed that the molecular regulatory axis controls wing morphology in nymphal and adult stages of locusts, offering a theoretical basis for the study of wing development mechanisms in hemimetabolous insects. Reference | Related Articles | Metrics Select Silencing transformer and transformer-2 in Zeugodacus cucurbitae causes defective sex determination with inviability of most pseudomales Qin Ma, Zizhen Fan, Ping Wang, Siya Ma, Jian Wen, Fengqin Cao, Xianwu Lin, Rihui Yan 2024, 23 (3): 938-947.   DOI: 10.1016/j.jia.2023.06.019 Abstract （416）      PDF in ScienceDirect       transformer is a switch gene for sex determination in many insects, which cooperates with transformer-2 that is expressed in both sexes to regulate female differentiation, particularly in dipterans.  Zeugodacus cucurbitae (Coquillett) is a very destructive pest worldwide, however, its sex determination pathway remains largely uncharacterized.  Here, we show that the female sex ratio is sharply reduced with knockdown of either transformer or transformer-2 by RNA interference in early embryos of Z. cucurbitae.  Most of the males grown from the embryos with transient transformer and transformer-2 suppression mated with wild-type females and produced mixed sex progeny, with one exception that produced only female progeny, and all of the few remaining males failed to mate with wild-type females and produced no progeny.  The exceptional male and those males with mating failure were XX pseudomales as determined by the detection of Y chromosome-linked Maleness-on-the-Y, indicating that most XX pseudomales are not viable.  The phenotypes of transformer and transformer-2 suggest that they play a key role in regulating sex determination and are required for female sexual development of Z. cucurbitae.  Our results will be beneficial to the understanding of sex determination in Z. cucurbitae and can facilitate the development of genetic sexing strains for its biological control. Reference | Related Articles | Metrics Select Low-density lipoprotein receptor-related protein 2 (LRP2) is required for lipid export in the midgut of the migratory locust, Locusta migratoria Yiyan Zhao, Weimin Liu, Xiaoming Zhao, Zhitao Yu, Hongfang Guo, Yang Yang, Hans Merzendorfer, Kun Yan Zhu, Jianzhen Zhang 2024, 23 (5): 1618-1633.   DOI: 10.1016/j.jia.2023.07.027 Abstract （410）      PDF in ScienceDirect       Low-density lipoprotein receptor-related protein 2 (LRP2) is a multifunctional endocytic receptor expressed in epithelial cells.  In mammals, it acts as an endocytic receptor that mediates the cellular uptake of cholesterol-containing apolipoproteins to maintain lipid homeostasis.  However, little is known about the role of LRP2 in lipid homeostasis in insects.  In the present study, we investigated the function of LRP2 in the migratory locust Locusta migratoria (LmLRP2).  The mRNA of LmLRP2 is widely distributed in various tissues, including integument, wing pads, foregut, midgut, hindgut, Malpighian tubules and fat body, and the amounts of LmLRP2 transcripts decreased gradually in the early stages and then increased in the late stages before ecdysis during the nymphal developmental stage.  Fluorescence immunohistochemistry revealed that the LmLRP2 protein is mainly located in cellular membranes of the midgut and hindgut.  Using RNAi to silence LmLRP2 caused molting defects in nymphs (more than 60%), and the neutral lipid was found to accumulate in the midgut and surface of the integument, but not in the fat body, of dsLmLRP2-treated nymphs.  The results of a lipidomics analysis showed that the main components of lipids (diglyceride and triglyceride) were significantly increased in the midgut, but decreased in the fat body and hemolymph.  Furthermore, the content of total triglyceride was significantly increased in the midgut, but markedly decreased in the fat body and hemolymph in dsLmLRP2-injected nymphs.  Our results indicate that LmLRP2 is located in the cellular membranes of midgut cells, and is required for lipid export from the midgut to the hemolymph and fat body in locusts. Reference | Related Articles | Metrics Select Halloween genes AhCYP307A2 and AhCYP314A1 modulate last instar larva–pupa–adult transition, ovarian development and oogenesis in Agasicles hygrophila (Coleoptera: Chrysomelidae) JIN Ji-su, LIU Yi-ran, ZHOU Zhong-shi, WAN Fang-hao, GUO Jian-ying 2023, 22 (3): 812-824.   DOI: 10.1016/j.jia.2022.08.021 Abstract （395）      PDF in ScienceDirect       In insects, ecdysteroids are synthesized by genes of the Halloween family and play important roles in several key developmental events, including molting and metamorphosis.  However, the roles of these genes in Agasicles hygrophila are still largely unknown.  In this study, the expression patterns of the two Halloween genes AhCYP307A2 and AhCYP314A1 were determined by quantitative PCR (qPCR) at different developmental stages.  Moreover, the functions of these two genes were explored using RNA interference (RNAi), and ovarian development was observed by dissecting the ovaries of A. hygrophila females.  The qPCR results showed that AhCYP307A2 and AhCYP314A1 were highly expressed in last instar larvae and in adult females.  In addition, AhCYP307A2 was also highly expressed in eggs and pupae but was markedly lower than in third-instar larvae and females.  The RNAi results showed that the injection of dsAhCYP307A2 or dsAhCYP314A1 markedly inhibited their expression and the transcription levels of three related AhVgs.  Knockdown of AhCYP307A2 or AhCYP314A1 significantly inhibited larval molting, impaired last instar larva–pupa–adult transition, delayed ovarian development, and stopped egg production (i.e., no eggs were laid).  These results indicate that AhCYP307A2 and AhCYP314A1 play important regulatory roles in last instar larva–pupa–adult transition and reproduction in A. hygrophila. Reference | Related Articles | Metrics Select Azole selenourea disrupted the midgut and caused malformed development of Plutella xylostella  GUO Xue-ying, HUANG Zi-hao, XIONG Lan-tu, DONG Li, HUANG Yue-kun, WEI Lin-hao, TANG Ri-yuan, WANG Zhi-lin, XU Han-hong 2023, 22 (4): 1104-1116.   DOI: 10.1016/j.jia.2022.09.001 Abstract （383）      PDF in ScienceDirect       Chemical insecticides targeting the digestive system of diamondback moth (DBM), Plutella xylostella, have not been developed.  The discovery of an insecticide with novel mode of action is a challenge for the control of DBM.  In this study, a class of selenium- and difluoromethyl-modified azoles (fluoroazole selenoureas, FASU) were designed and synthesized for the control of DBM.  Of these azoles, compound B4 showed the highest insecticidal activity against DBM.  The LC50 of third- and second-instar larvae reached 32.3 and 4.6 μg mL–1, respectively.  The midgut tissue of larvae was severely disrupted, and the larval intestinal tissue was dotted with unique red spots after treatment with compound B4.  Compound B4 led to disintegration of the peritrophic matrix, swelling of the midgut epithelium, fracture of the microvilli, and extensive leakage of cellular debris in the midgut lumen.  Surviving larvae grew very slowly, and the larval duration was significantly prolonged after exposure to compound B4 at sublethal doses (LC10, LC25 and LC50).  Furthermore, the pupation rate, emergence rate and pupae weight were significantly decreased.  Compound B4 also induced abnormal pupae, causing adults to be trapped in the cocoon or failure to fly due to twisted wings.  These results demonstrated that FASU could reduce the population of DBM in sublethal doses.  FASU is the first synthetic insecticidal lead compound that has been shown to disrupt the midgut tissue of the larvae of DBM, and its mode of action totally differs from that of commercial chemical insecticides. Reference | Related Articles | Metrics Select The role of cAMP-dependent protein kinase A in the formation of long-term memory in Bactrocera dorsalis Jinxin Yu, Yanmin Hui, Jiayi He, Yinghao Yu, Zhengbing Wang, Siquan Ling, Wei Wang, Xinnian Zeng, Jiali Liu 2024, 23 (2): 605-620.   DOI: 10.1016/j.jia.2023.07.016 Abstract （362）      PDF in ScienceDirect       The cAMP-dependent protein kinase A (PKA) signaling pathway has long been considered critical for long-term memory (LTM) formation.  Previous studies have mostly focused on the role of PKA signaling in LTM induction by multiple spaced conditioning with less attention to LTM induction by a single conditioning.  Here, we conducted behavioral-pharmacology, enzyme immunoassay and RNA interference experiments to study the role of the PKA signaling pathway in LTM formation in the agricultural pest Bactrocera dorsalis, which has a strong memory capacity allowing it to form a two-day memory even from a single conditioning trial.  We found that either blocking or activating PKA prior to conditioning pretreatment affected multiple spaced LTM, and conversely, they did not affect LTM formed by single conditioning.  This was further confirmed by enzyme-linked immunosorbent assay (ELISA) and silencing of the protein kinase regulatory subunit 2 and catalytic subunit 1.  Taken together, these results suggest that activating PKA during memory acquisition helps to induce the LTM formed by multiple spaced conditioning but not by a single conditioning.  Our findings challenge the conserved role of PKA signaling in LTM, which provides a basis for the greater diversity of molecular mechanisms underlying LTM formation across species, as well as possible functional and evolutionary implications. Reference | Related Articles | Metrics Select Disruption of a microvitellogenin gene impairs eggshell formation in Mythimna separata Lingling Li, Junhong Fu, Changgeng Dai, Yuhang Zhou, Yang Hu, Hongbo Li 2024, 23 (11): 3801-3811.   DOI: 10.1016/j.jia.2024.03.057 Abstract （360）      PDF in ScienceDirect       Microvitellogenin (mVg) belongs to the lepidopteran-specific lipoprotein_11 super family and is thought to be involved in insect reproduction.  However, the function of mVg in reproduction has not been established.  In this study, we identified and characterized MsmVg in Mythimna separata, a destructive insect pest of grain crops.  MsmVg is comprised of a 1,310 bp open reading frame (ORF) encoding 437 amino acids.  Structural analysis showed that MsmVg contains three conserved domains in the lipoprotein_11 super family, including the all-α-N-terminal domain (NTD), a Pseudomonas putida homologous domain (PPD), and an all-β-C-terminal domain (CTD).  MsmVg was highly expressed in mature female adults and enriched in the ovaries of 3-day-old female adults.  Disruption of MsmVg by RNA interference did not change the expression of MsmVg, vitellogenin (MsVg) or the vitellogenin receptor (MsVgR) in fat bodies, but it inhibited their transcription in ovaries.  Phenotype analysis showed that knockdown of MsmVg did not affect yolk deposition in ovaries, but impaired eggshell formation and led to a reduction in the reproductive capacity.  Furthermore, knockdown of MsmVg significantly inhibited the expression of genes associated with eggshell formation (MsChP1-3 and MsFcP3C).  Taken together, these data suggest that MsmVg plays an important role in female reproduction by affecting eggshell formation in M. separata, which provides a potential target for managing this insect pest. Reference | Related Articles | Metrics Select The life-history trait trade-offs mediated by reproduction and immunity in the brown planthopper, Nilaparvata lugens Stål Dan Sun, Hongfeng Wang, Jiahui Zeng, Qiuchen Xu, Mingyun Wang, Xiaoping Yu, Xuping Shentu 2024, 23 (6): 2018-2032.   DOI: 10.1016/j.jia.2024.03.062 Abstract （348）      PDF in ScienceDirect       Reproduction and immune defense are costly functions, and they are expected to tradeoff with each other to drive evolution.  The brown planthopper (BPH), Nilaparvata lugens Stål (Hemiptera, Delphacidae), is a global superpest that mostly damages rice crops.  Yeast-like symbionts (YLS) exist in the abdominal fat body tissue and are tightly associated with the development, growth, and reproduction of BPH.  Our previous research demonstrated that mating behavior promotes the release of YLS from the fat body into the hemolymph in the BPH, thereby triggering an immune response.  Additionally, the fitness costs related to life-history traits of BPH (such as survival rate) have a strong dependence on the relative abundance of YLS.  However, the possible relationship between reproduction and the immune response in BPH has not been identified.  In this study, an omics-based approach was used to analyze the transcriptome of fat body tissues in mated and unmated BPH at 72 h post-eclosion, from which two antimicrobial peptide genes, NlDefensin A (NlDfA) and NlDefensin B (NlDfB), were selected since they were highly expressed in mated BPH.  Subsequently, the full-length cDNA sequences of the NlDfA and NlDfB genes were cloned and analyzed.  qPCR results showed up-regulation of the NlDfA and NlDfB genes in mated BPH when compared to unmated BPH.  Spatial-temporal expression analysis indicated that the NlDfA and NlDfB genes were expressed in all tissues and developmental stages, and they were most highly expressed in the fat body at 24 h post-eclosion.  Moreover, the symbionts in BPH were significantly inhibited by the in vitro expression of the NlDfA and NlDfB proteins.  Furthermore, RNA interference (RNAi)-mediated suppression of NlDfA and NlDfB dramatically increased the relative abundance of YLS in the fat body, while YLS in the hemolymph decreased significantly.  These BPHs also displayed some fitness disadvantages in survival, fecundity, hatchability, and possibly the vertical transmission of YLS from hemolymph to egg.  Our results indicated that mating could heighten the immunity of BPH by up-regulating the expression of the NlDfA and NlDfB genes, which protect the host from pathogen challenges during reproduction.  However, the reduced content of YLS may act as a fitness disadvantage in dictating the life-history traits of BPH.  This work has significant theoretical and practical implications for the precise green control technology that involves crucial gene targeting, as well as for the “endosymbionts for pest control” strategy in insects. Reference | Related Articles | Metrics Select Neuropeptide signaling systems are involved in regulating thermal tolerance in the oriental fruit fly Yang Yang, Hongfei Li, Changhao Liang, Donghai He, Hang Zhao, Hongbo Jiang, Jinjun Wang 2024, 23 (12): 4147-4160.   DOI: 10.1016/j.jia.2024.04.003 Abstract （294）      PDF in ScienceDirect       Neuropeptides and their receptors are involved in the regulation and coordination of various physiological processes in insects.  Although various neuropeptides have been identified previously, the corresponding receptors remain unknown in the oriental fruit fly, Bactrocera dorsalis, an important agricultural insect pest.  It is also unclear whether neuropeptide signaling systems are involved in regulating the thermal tolerance of this notorious pest.  Here, we systematically identified 44 putative neuropeptide receptor genes which encode 66 protein sequences, and analyzed the spatio-temporal expression patterns of the neuropeptide ligands and their receptor genes in B. dorsalis.  We also analyzed changes in their transcript accumulation in two thermo-tolerant populations (heat and cold) of B. dorsalis.  The results showed that numerous neuropeptides and receptors participate in responding to thermal stresses during acclimation.  In particular, the expression of short neuropeptide F (sNPF) was up-regulated in the heat-tolerant population of B. dorsalis.  Moreover, proteomic data showed that sNPF was up-regulated in both thermo-tolerant populations of B. dorsalis.  The functional verification based on CRISPR/Cas9 demonstrated that sNPF is involved in regulating the tolerance to thermal stresses.  The results of this study enrich our knowledge on the function of neuropeptide sNPF in insects.  Moreover, this study demonstrated the role of neuropeptide signaling systems in thermal adaptation, contributing to a better understanding of the rapid invasiveness of B. dorsalis around the world. Reference | Related Articles | Metrics Select Adipokinetic hormone signaling regulates adult dehydration resistance in the migratory locust Xianliang Huang, Dai Shi, Kai Deng, Shuzhen Jia, Ding Ding, Li Hou, Bing Chen 2024, 23 (9): 3104-3117.   DOI: 10.1016/j.jia.2024.03.019 Abstract （282）      PDF in ScienceDirect       Drought events have become more severe under climate change, and this can pose a major threat to the survival of various organisms.  The molecular mechanisms involved in dehydration resistance are not well known.  Here, adults of the migratory locust, Locusta migratoria, were subjected to food-mediated dehydration, and adipokinetic hormone (AKH) signaling was found to play a key role in regulating dehydration resistance.  Specifically, dehydration shortened the lifespan, increased the body weight loss, and reduced the water loss rate in adult locusts.  Global transcriptome profiles revealed variations in tissue-specific gene expression between dehydration-resistant locusts and normal locusts.  Importantly, dehydration selection and exposure induced prominent expression of AKH genes in the retrocerebral complex of adult locusts.  Furthermore, individual knockdown of AKH1, AKH2, or AKH receptor (AKHR) accelerated water loss and shortened the lifespan of adult locusts under dehydration conditions, and trehalose supplementation ameliorated the negative effects caused by interference with AKH or AKHR.  These findings demonstrated that AKH/AKHR signaling-dependent trehalose metabolism plays a crucial role in regulating locust dehydration resistance and thus provide novel insights into the regulatory mechanism underlying drought resistance. Reference | Related Articles | Metrics Select Tissue distribution of cadmium and its effect on reproduction in Spodoptera exigua Honghua Su, Menglu Wu, Yong Yang, Yan Deng, Yizhong Yang, Qingming Sun 2024, 23 (1): 195-204.   DOI: 10.1016/j.jia.2023.08.010 Abstract （254）      PDF in ScienceDirect       Vegetable fields are often contaminated by heavy metals, and Spodoptera exigua is a major vegetable pest which is stressed by heavy metals mainly by feeding.  In this study, cadmium accumulation in the tissues of S. exigua exposed to cadmium and its effects on the growth and development of the parents and the offspring were investigated.  Under the stress of different concentrations of cadmium (0.2, 3.2, and 51.2 mg kg–1), the cadmium content in each tissue of S. exigua increased in a dose-dependent manner.  At the larval stage, the highest cadmium accumulation was found in midgut in all three cadmium treatments, but at the adult stage, the highest cadmium content was found in fat body.  In addition, the cadmium content in ovaries was much higher than in testes.  When F1 S. exigua was stressed by cadmium and the F2 generation was not fed a cadmium-containing diet, the larval survival, pupation rate, emergence rate and fecundity of the F2 generation were significantly reduced in the 51.2 mg kg–1 treatment compared to the corresponding F1 generation.  Even in the F2 generation of the 3.2 mg kg–1 treatment, the fecundity was significantly lower than in the parental generation.  The fecundity of the only-female stressed treatment was significantly lower than that of the only-male stressed treatment at the 3.2 and 51.2 mg kg–1 cadmium exposure levels.  When only mothers were stressed at the larval stage, the fecundity of the F2 generation was significantly lower than that of the F1 generation in the 51.2 mg kg–1 treatment, and it was also significantly lower than in the 3.2 and 0.2 mg kg–1 treatments.  The results of our study can provide useful information for forecasting the population increase trends under different heavy metal stress conditions and for the reliable environmental risk assessment of heavy metal pollution. Reference | Related Articles | Metrics Select The synergistic regulatory effect of PTP1B and PTK inhibitors on the development of Oedaleus decorus asiaticus Bei-Bienko Shuang Li, Sibo Liu, Chaomin Xu, Shiqian Feng, Xiongbing Tu, Zehua Zhang 2024, 23 (8): 2752-2763.   DOI: 10.1016/j.jia.2023.12.020 Abstract （232）      PDF in ScienceDirect       Tyrosine phosphorylation is crucial for controlling normal cell growth, survival, intercellular communication, gene transcription, immune responses, and other processes.  protein tyrosine phosphatase (PTP) and protein tyrosine kinases (PTK) can achieve this goal by regulating multiple signaling pathways.  Oedaleus decorus asiaticus is an important pest that infests the Mongolian Plateau grassland.  We aimed to evaluate the survival rate, growth rate, overall performance, and ovarian developmental morphology of the 4th instar nymphs of O. decorus asiaticus while inhibiting the activity of protein tyrosine phosphatase-1B (PTP1B) and PTK.  In addition, the expression and protein phosphorylation levels of key genes in the MAPK signaling pathway and antioxidant enzyme activity were assessed.  The results showed no significant differences in survival rate, growth rate, or overall performance between PTP1B inhibitor treatment and control.  However, after PTK inhibitor treatment, these indexes were significantly lower than those in the control.  The ovarian size of female larvae after 15 days of treatment with PTK inhibitors showed significantly slower development, while female larvae treated with PTP1B exhibited faster ovarian growth than the control group.  In comparison to controls and nymphs treated with PTK inhibitors, the expression and phosphorylation levels of key genes in the MAPK signaling pathway under PTP1B inhibitor treatments were significantly higher in 4th instar nymphs.  However, reactiveoxygen (ROS) species levels and the activities of NADPH oxidase and other antioxidant enzymes were considerably reduced, although they were significantly greater in the PTK inhibitor treatment.  The results suggest that PTP1B and PTK feedback inhibition in the mitogen-activated-protein kinases (MAPK) signal transfer can regulate the physiological metabolism of the insect as well as its developmental rate.  These findings can facilitate future uses of PTP1B and PTK inhibitors in controlling insect development to help control pest populations. 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