Search Results (1,343)

The family Lecithoceridae represents one of the most diverse yet understudied groups within Lepidoptera, with numerous unresolved taxonomic problems that require urgent attention. This study reports one new species and four newly recorded species of the genus Amaloxestis Gozmány, 1973 from China. Amaloxestis similinepalensis Yu is described as new to science, while A. astringens Gozmány, 1973, A. callitricha (Meyrick, 1910), A. chiloptila (Meyrick, 1921) and A. nepalensis Gozmány, 1973 are newly recorded from China. All treated species were identified based on morphological characters and molecular phylogenetic evidence. Additionally, the females of A. chiloptila and A. nepalensis are described for the first time. Full article

Bedellia somnulentella (Lepidoptera: Bedelliidae) is an invasive, leaf-mining, and defoliating pest of sweet potatoes (Ipomoea batatas L.) that has recently established in Brazil. Its colonization and infestation levels in cultivated fields are influenced by the availability of wild Ipomoea species that sustain populations during off-season periods. The objective was to evaluate the biology and life history of B. somnulentella feeding on wild plants of the genus Ipomoea and on I. batatas cv. Beauregard. Vegetative and reproductive parts of Ipomoea plants were collected and cultivated, and the biology and life history of B. somnulentella were studied using twenty adult pairs of the insect per host plant in a climate-controlled room. The wild species Ipomoea hederifolia L., Ipomoea indica (Burm.f.) Merr., Ipomoea purpurea L., and cultivated I. batatas were used for the assays. The experiment followed a completely randomized design with ten replicates. Hatching, larval stages, prepupa, pupa, and adult phases were observed and recorded daily. Variations in the coloration of B. somnulentella larvae feeding on leaves of I. hederifolia, I. indica, and I. purpurea were observed. The survival and development of B. somnulentella were higher on I. batatas and I. hederifolia than on I. indica and I. purpurea, mainly during the larval and adult stages. The results provide information on infestation in alternative wild hosts and on biological aspects of B. somnulentella. Full article

The use of Steinernema carpocapsae infective juveniles as biological control agents is a long-standing practice, yet the oral impact of their secreted venom proteins on crop pests remains largely unknown. We evaluated the oral toxicity of S. carpocapsae venom proteins against Spodoptera frugiperda using artificial diet assays. Ingestion caused significant dose-dependent toxicity in early-instar larvae, resulting in mortality and a prolonged developmental duration. Carry-over effects were profound; treated pupae were smaller and malformed, with only 19% of larvae fed on 1000 ng g⁻¹ venom protein-supplemented diet reaching adulthood compared to 92% in controls. Surviving adults lived 30% fewer days and laid over 90% fewer morphologically normal eggs. These physiological disruptions coincided with elevated oxidative stress and detoxification enzyme activity, suggesting the venom induces oxidative and detoxification responses, which may be associated with the observed phenotypic alterations. This study provides the first demonstration of the oral toxicity of entomopathogenic nematode venom proteins, positioning them as a promising resource for the discovery of novel insecticidal proteins for sustainable pest management. Full article

Lepidoptera constitute a major group of agricultural and forestry pests. Therefore, investigating the immune mechanisms of the model species Bombyx mori may provide valuable insights for the development of improved pest management strategies. In insects, phenoloxidase (PO) and dopa decarboxylase (DDC) in immune melanization have been widely studied individually, yet their relative contributions have rarely been investigated. Here, we demonstrate that pharmacological inhibition of either PO or DDC in Escherichia coli-infected larvae significantly suppresses hemolymph melanization, with PO inhibition causing a more pronounced reduction than DDC inhibition. Consistently, RNA interference-mediated knockdown of BmPPO1 or BmPPO2 markedly decreased hemolymph melanization following infection. This results in both PO and DDC contributing to immune-induced hemolymph melanization, with PO playing a dominant role in this process. In contrast, compared to PO inhibition, DDC inhibition leads to significant damage to hemolymph antibacterial activity and cellular immune responses, including hemocyte aggregation, encapsulation, and phagocytosis. In addition, compared with the knockdown of BmPPO1 or BmPPO2, the knockdown of BmDDC leads to a more severe decrease in antibacterial activity and cellular immune function. Exogenous addition of dopamine can partially rescue cell damage, indicating that both DDC and PO play a role in cellular immunity, but DDC has a slightly stronger effect. Overall, this study provides important insights into the immunity of hemolymph in insects and other arthropods. Full article

Lipopolysaccharide-induced tumor necrosis factor alpha factor (LITAF) as a crucial cytokine can mediate the inflammatory and immune regulatory responses of an organism. It plays a significant mediatory role in the innate immune system of insects. Firstly, the LITAF family of cotton bollworm (Helicoverpa armigera, Lepidoptera: Noctuidae) was analyzed, and the differentially expressed genes of HaLITAFs were screened from the 2-tridecanone-treated transcriptome. Subsequently, these two differentially expressed HaLITAF genes were cloned and analyzed, and the effect of different larval stages, tissues, and plant secondary metabolites on their gene expression were detected in H. armigera. The cotton bollworm contains 13 LITAF genes, and there are no repetitive sequences among them. Upon 2-tridecanone treatment, only HaLITAF5 and HaLITAF7 were significantly upregulated in the LITAF family of cotton bollworm larvae after 6 h. The HaLITAF5 and HaLITAF7 proteins, respectively, comprised 78 and 113 amino acids, and both contained a CXXC motif, hydrophobic amino acid region and HXCPXCXXXXG motif. Both of them belong to the LITAF analogues (zf-LITAF-like) superfamily. The expressions of HaLITAF5 and HaLITAF7 were both the lowest in fourth-instar larvae and the highest in sixth-instar larvae, and both were abundantly expressed in the midgut of sixth-instar larvae. Following a 28 h treatment with 2-tridecanone, the expression levels of HaLITAF5 and HaLITAF7 peaked. HaLITAF7 exhibited the highest expression level after a 4 h exposure to tannic acid, whereas HaLITAF5 reached its peak after 28 h of tannic acid treatment. The maximum expression levels of HaLITAF5 and HaLITAF7 were observed after 28 h and 4 h of quercetin treatment, respectively. Subsequent to ZQ-8 treatment, HaLITAF5 expression peaked at 28 h, while HaLITAF7 expression peaked at 8 h. Both HaLITAF5 and HaLITAF7 were overexpressed after different kinds of plant secondary metabolite stresses, and thereby, they may be regulated in the expression of genes related to downstream detoxification metabolic processes. This provides a theoretical foundation for further studies on the functional mechanism of the LITAF gene in H. armigera. Full article

Pontia edusa is a nectar-feeding butterfly widely distributed in Europe, northwestern India, Siberia, North Africa (extending to Ethiopia), and most regions of China; however, detailed information on the fine morphology of its proboscis remains limited. In this study, scanning electron microscopy was used to examine the external morphology, zonal organization, and sensilla composition of the adult proboscis, and sexual differences in selected morphological parameters were statistically analyzed. The proboscis consists of a pair of elongated maxillary galeae that interlock via dorsal and ventral legulae to form a continuous food canal. Based on structural variation in the dorsal legulae, the proboscis can be divided into three zones. Zone 1 is characterized by tightly interlocked legulae and serrated external ridges; Zone 2 shows enlarged interlegular gaps and gradual modification of external surface ornamentation; and Zone 3 lacks dorsal legulae and bears flake-like bumps. Three major types of sensilla were identified on the proboscis, including sensilla chaetica, basiconica, and styloconica, comprising six subtypes in total. The sensilla chaetica subtype sc2, restricted to the ventral surface of the proximal proboscis, represents a previously unreported morphological feature for P. edusa. These results provide a detailed morphological framework for the proboscis of P. edusa and expand the comparative basis for evaluating structural diversity and regionalization patterns of the proboscis in flower-visiting pierid butterflies. Full article

Sexual reproduction is the predominant mode of reproduction in animals, and spermatogenesis is the fundamental step in this process. As the model organism for lepidopteran, the silkworm Bombyx mori exhibits typical dichotomous spermatogenesis, producing both nucleated (eupyrene) and anucleate (apyrene) sperm. Leucylaminopeptidases (LAPs), members of the M17 metalloprotease family, are characterized by their ability to cleave leucine residues from the N-terminus of peptides. In addition to this canonical function, they have been implicated in male fertility in mammals and Diptera. Nevertheless, whether LAPs are required for dimorphic spermatogenesis in Lepidoptera remains to be clarified. Here, we demonstrated that Sperm-Leucylaminopeptidase (S-LAP) plays vital roles in the silkworm eupyrene sperm development. Similar to the testis-specific expression pattern of eight S-LAPs in Drosophila melanogaster, BmS-LAP was also predominantly expressed in testis. Depletion of BmS-LAP via CRISPR/Cas9 system resulted in male sterility, while the fertility of female mutant was unaffected. Notably, male mutants displayed severe defects in the formation and migration of eupyrene sperm, whereas apyrene sperm development appeared normal. In addition, RNA-seq and qRT-PCR analyses demonstrated that spermatogenesis defects were associated with energy metabolism and flagellar assembly. Our study provides the first evidence that LAP is necessary for dimorphic spermatogenesis in Lepidopteran, offering new insights into the molecular basis of male infertility. Full article

Encapsulation is a major cellular defense reaction in lepidopterans. However, in the oriental armyworm (Mythimna separata), the molecular regulators that coordinate hemocyte adhesion and multilayer capsule assembly remain poorly defined. In this study, we identified Mythimna separata encapsulation related gene 1 (MysERG1) as a novel cellular immune regulatory gene. MysERG1 transcripts were most abundant in hemocytes and were notably upregulated in adherent hemocytes as well as in samples of capsules, indicating an association with adhesion-dependent hemocyte activation. Following separation of granulocytes and plasmatocytes, MysERG1 expression was observed to be higher in adherent plasmatocytes than in adherent granulocytes. However, recombinant MysERG1 selectively increased granulocyte adhesion but did not significantly affect plasmatocyte adhesion and was specifically localized on granulocytes. Additionally, recombinant MysERG1 enhanced hemocyte aggregation on foreign surfaces, highlighting its functional role in facilitating encapsulation. Functional knockdown using double-stranded RNA significantly reduced the size of the capsules, indicating that MysERG1 is required for robust capsule formation. This study identifies MysERG1 as a novel factor involved in hemocyte cooperation during encapsulation in M. separata and presents a conceptual framework for inter-hemocyte communication mechanisms in lepidopteran cellular immunity. Full article

Transcriptome atlases can be used to examine the spatiotemporal dynamics of gene expression, thereby enabling the generation of genome-wide resources for understanding complex biological processes. In the silkworm Bombyx mori, transcriptomes serve as crucial datasets for elucidating the mechanisms underlying economically important traits. In this study, we integrated 832 transcriptome datasets across all developmental stages and tissues and performed whole-genome-scale transcriptome sequencing (RNAseq) on five critical tissues from silkworm strains Xian8 and 9211. We identified 5773 and 3323 housekeeping genes expressed across all developmental stages and tissues, respectively, and these genes were primarily enriched in cellular signaling, transport, structural organization, DNA repair, and RNA processing pathways. We also identified 27 stage-specific genes and 58 tissue-specific genes, providing candidate markers for future single-cell and spatial transcriptomics. A large number of alternative splicing events were detected from 832 NGS samples, indicating the critical roles of alternative splicing in silkworm development. Interestingly, only 10 long-read full-length transcriptome samples from Xian8 and 9211 yielded results comparable to the NGS in terms of novel genes and alternative splicing events, and these multi-tissue comparative analyses also revealed significant differences in alternative splicing patterns, underlining the necessity of long-read sequencing for such research. These datasets not only advance functional genomics research in Lepidoptera but also provide molecular signatures for silkworm strain-specific comparisons and association analyses with differential phenotypes. Silkworm pan-transcriptomics, by analyzing multidimensional transcriptional regulatory networks and gene-expression dynamics, can facilitate multidisciplinary integration and accelerate the breeding of high-yield and high-quality silkworm varieties. Full article

Diapause hormone (DH) is an important endocrine substance capable of influencing diapause in Lepidoptera moths that is encoded by the neuropeptide hormone DH-PBAN gene. Imidazole derivative KK-42 is a synthetic insect growth regulator that can affect diapause in Lepidoptera moths, and appears to have an opposite physiological function to DH. To test the hypothesis that KK-42 may be operating through DH to affect diapause, here, we used two Lepidoptera species Bombyx mori L. and Antheraea pernyi that enter egg and pupal diapause, respectively, through examining whether KK-42 can influence DH-PBAN and some associated mRNA expression. We found that the protein sequences of DH-PBAN in insects were highly variable, although the PRXamide C-terminus was conserved. We also found that KK-42 induced significant up-regulation and prolonged expression duration of DH-PBAN in both A. pernyi and B. mori pupae, as well as in trimolter larvae of B. mori that were induced by the application of KK-42 from the normal tetramolter larvae. In addition, KK-42 can significantly upregulate glutamic acid decarboxylase (GAD) expression in B. mori in transcriptome data. Our findings suggested that KK-42 influences diapause by upregulating GAD expression, promoting DH accumulation to prolong the secretion time of DH-PBAN. Full article

The preservation of biological control agents in agroecosystems while simultaneously ensuring the use of insecticides with selective chemical profiles is crucial for sustainable pest management. In this study, we aimed to evaluate the selectivity of insecticides used in the management of Phthorimaea (Tuta) absoluta in tomato crops during the adult stage of Trichogramma pretiosum. The selectivity tests were conducted according to the standards of the International Organization for Biological and Integrated Control/West Palearctic Regional Section. The bioassay was used to assess the direct effects of treatments on T. pretiosum adults through tarsal contact. Specifically, 42 chemical and/or biological insecticides commonly applied in tomato cultivation were used to manage P. absoluta. The insecticides identified as selective (Class 1) for adult T. pretiosum under laboratory conditions were recommended for use in integrated pest management (IPM) programs in tomato crops. These included Hayate^®, Agree^®, Dipel^®, Xentari^®, Tarik^®, Bioexos^®, Verpavex^®, Spodovir^®, Verpavex^® + Spodovir^®, Tuta Vir^®, BioBrev^®, Diplomata^®, VirControl C.i^®, and VirControl S.F^®. Insecticides belonging to the following chemical groups were not selective, that is, they were harmful to T. pretiosum adults: avermectins, milbemycins, diacylhydrazines, oxadiazines, semicarbazones, spinosyns, diamides, chlorfenapyr, nereistoxin analogs, pyrethroids, carbamates, butenolides, isoxazoline, azadirachtin, quinolizidine alkaloids, METI, and benzoylureas. Therefore, these insecticides should be used with caution in IPM programs that target P. absoluta in tomato crops. Full article

Field trials were conducted to define several parameters associated with adding LEDs to monitoring traps for codling moth (CM), Cydia pomonella (L.), using both a sex pheromone lure (PH1X) and a non-pheromone lure (CM4K). Traps with LEDs emitting at a peak of 395 nm with 1000–2000 mW/m² were the most effective. Lights with greater intensities caught similar numbers of CMs and significantly more non-targets. Adding the UV-A lights did not increase moth catches early in the season with either the PH1X or CM4K lures. However, UV-A LEDs, when used with these two lures, significantly increased total moth catches 7- and 3-fold in July and August, respectively. The addition of the UV-A LEDs allowed CM4K-baited traps to perform significantly better in previously limiting situations, such as in weedy orchards, and in pear relative to apple. Distance from the light source is a key factor affecting light energy. Irradiance dropped >90% at 15 cm, which is the distance from the lure to the entrance of a standard delta trap. A smaller trap (7.5 cm radius) had a 4-fold greater irradiance at its entrance and caught greater numbers of non-targets but not CMs than delta traps without LEDs. Full article

During eukaryotes evolution, mitochondrial DNA (mtDNA) fragments integrate into nuclear genomes, forming nuclear mitochondrial DNA sequences (Numts). Tortricidae (Lepidoptera), a species-rich and economically critical family, lacks systematic characterization of Numts, which hinders reliable molecular research. Here, we systematically characterized Numts in 27 Tortricidae species spanning two subfamilies via genome download, mitochondrial genome annotation, and Numt identification and characterization. With each species’ mtDNA as query, Numt identification was performed with an E-value threshold of 10⁻⁴ and a sequence similarity cut-off of >60%, with a minimum length of 50 bp to exclude spurious hits. Results showed that all species contained Numts, with copy numbers varying drastically (9–208). Numt numbers positively correlated with nuclear genome length, but not mitochondrial genome length. Numts insertion flanking regions had significantly higher AT content than nuclear genome, indicating the insertion preference for AT-rich regions. Numts were predominantly derived from the mitochondrial cox1 gene, highlighting the risk of co-amplification when cox1 is used as a DNA barcode for species identification or phylogenetic studies. This study represents a systematic charaterizition of copy number, length distribution, insertion sequence preferences, and mitochondrial gene origins of Numts in Tortricidae, offering valuable references for refining molecular systematics, comparative genomics, and pest management in Tortricidae and related lepidopteran groups. Full article

The yellow peach moth, Conogethes punctiferalis, is a destructive polyphagous pest and poses a severe threat to the fruit industry and field crops worldwide with its continuously increasing population and expanding host range in recent years. Despite the severe damage caused by C. punctiferalis larvae, their antennae and mouthparts, equipped with abundant sensilla responsible for feeding behavior, have not been investigated in detail. In our study, the antennae, mouthparts, and associated sensilla of first-instar and mature larvae of C. punctiferalis were examined with light and scanning electron microscopy. Our results revealed no obvious morphological differences between the two instars in the basic composition of the antennae and mouthparts, or in the types, distribution, and numbers of sensilla. The antenna is three-segmented, with no sensilla on the scape, three sensilla basiconica and two sensilla chaetica on the pedicel, and three sensilla basiconica and one sensillum styloconicum on the flagellum. The mouthparts of C. punctiferalis are typically mandibulate and consist of a labrum-epipharynx, paired mandibles, a pair of maxillae, a labium, and a hypopharynx. Six types of sensilla were primarily concentrated on the labrum-epipharynx, maxilla, and labial palp, including sensilla chaetica, sensilla basiconica, sensilla styloconica, sensilla digitiformia, sensilla epipharyngea, and sensilla placodea. We conducted a systematic analysis of the characteristics of sensilla and discussed their variation in the context of Lepidoptera phylogeny. The potential functions of the sensilla have also been inferred. The study could advance our understanding of the behavioral ecology of C. punctiferalis and provide potentially useful information on the development of pest control technologies. Full article

The bollworm/corn earworm, Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae), is one of the most economically damaging crop pests in North America. Colonies of H. zea are notoriously difficult to maintain and frequently collapse in laboratory rearing. The persistent difficulty in maintaining healthy H. zea colonies has become a major obstacle to performing many research activities on the insect. To optimize colony maintenance, six populations were evaluated across three trials and six tests examining pupal maturity at diet removal, adult emergence synchrony, and cohort size at mating and reproduction. Females emerging from mature pupae produced more eggs than those from mid-aged (5–7 d) or young pupae (0–2 d). Synchronizing male and female emergence within one day yielded higher mating frequency, spermatophore transfer, and progeny, whereas a two-day difference reduced these metrics by 45–67%. Adult cohort size also influenced the outcomes, with ≥10 males and ≥10 females per cage enhancing reproductive success. Most matings occurred on nights 2–3, peaking within 2.5 h after lights off. Positive correlations were observed among mating frequency, spermatophore transfer, and progeny production. Overall, optimal performance was achieved by removing pupae only at maturity, synchronizing adult emergence within one day, and maintaining larger adult cohorts. These findings should establish key conditions to improve the mating success, reproduction, and laboratory rearing of H. zea. Full article