Archives of Insect Biochemistry and Physiology最新文献

Patched-related (Ptr) is a transmembrane protein implicated in developmental processes in Drosophila melanogaster, yet its precise role remains incompletely understood. Here, we use Ptr^23c null mutants to investigate the functional significance of Ptr through the entire life cycle monitoring survival during embryonic, larval, pupal and adult development, and studying larval locomotion and muscle structure. We report that Ptr^23c larvae displayed impaired hatching, indicative of defective embryonic development. Moreover, mutant larvae exhibited reduced mobility and lethargy, suggesting a potential involvement of Ptr in neuromuscular function. Morphological analysis of somatic muscles in mutant larvae revealed enlarged cell nuclei. Despite high preadult mortality, a subset of Ptr^23c mutant adults display an unexpected extension in lifespan compared to controls, implicating Ptr in the regulation of longevity. Our findings provide critical insights into the multifaceted role of Ptr in Drosophila development, highlighting its contributions to post-embryonic survival, neuromuscular function, and lifespan regulation. This study underscores the significance of exploring broader genetic networks to unravel the complexities of developmental processes.

The Oriental fruit fly, Bactrocera dorsalis (B. dorsalis) is a highly invasive, widely distributed notorious pest restricting global fruit trade immensely. There are several approaches to managing this pest, still require newer approaches. In this regard, recently a novel approach called precision-guided sterile insect technique (pgSIT) is gaining momentum in inducing both female sex elimination or sex conversion and male sterility at one go. Developing a species-specific pgSIT system requires validation of targets such as sex determination and spermatogenesis genes. In this regard, B. dorsalis is highly amenable for area-wide pest management and in the present study, we have validated the loss-of-function of the spermatogenesis-related gene, tektin1 using the CRISPR/Cas9 ribonucleoprotein (RNP) complex. This gene was cloned from the local isolate of B. dorsalis and two promising single guide RNAs (sgRNAs) were designed and validated through in vitro restriction analysis. Injection of the RNP complex (sgRNA + Cas9 protein) into the G0 embryo resulted in three adult males carrying mutations at the target site. The phenotype of the mutants was determined through crossing studies, namely, △1♂ × WT ♀, △2♂ × WT ♀, △3♂ × WT ♀, and WT ♂ × WT ♀ and that showed hatching rates of 0%, 11.70%, 0%, and 45.12%, respectively. The mutant males had more nonviable sperm as compared to control. This study underscores the pivotal role of the Bdtektin1 gene for male fertility and is a promising candidate for further development of pgSIT system for B. dorsalis.

Insecticides play a crucial role as the primary means of controlling agricultural pests, preventing significant damage to crops. However, the misuse of these insecticides has led to the development of resistance in insect pests against major classes of these chemicals. The emergence of resistance poses a serious threat, especially when alternative options for crop protection are limited for farmers. Addressing this challenge and developing new, effective, and sustainable pest management approaches is not merely essential but also critically important. In the absence of alternative solutions, understanding the root causes behind the development of resistance in insects becomes a critical necessity. Without this understanding, the formulation of effective approaches to combat resistance remains elusive. With insecticides playing a vital role in global food security and public health, understanding and mitigating resistance are paramount. Given the growing concern over insect resistance to insecticides, this review addresses a crucial research gap by thoroughly examining the causes, mechanisms, and potential solutions. The review examines factors driving resistance, such as evolutionary pressure and excessive pesticide use, and provides a detailed analysis of mechanisms, including detoxifying enzyme overproduction and target site mutations. Providing an analysis of potential solutions, it discusses integrated pest management, strategic insecticide rotation, and the use of new pest control technologies and biological agents. Emphasizing the urgency of a multifaceted approach, the review provides a concise roadmap for sustainable pest management, guiding future research and applications.

The effects of feeding on insect larvae treated with pesticide on the biological and biochemical characteristics of Arma chinensis were investigated. In the F₀ generation, the developmental duration and preoviposition period were shortened, the average number of eggs laid was reduced, and the net reproductive rate and mean generation time were significantly lower in the treatment group compared to those in the control group. The average number of eggs laid by the F₁ generation of A. chinensis was lower in the treatment group. The intrinsic rates of increase, finite rates of increase and net reproductive rates were significantly lower in the F₁ generation in the treatment group than those in the control group. The activities of CarE and GST were significantly induced, while the activity of AChE was inhibited in the A. chinensis in the treatment group. The activities of trypsin and THL were significantly induced in the treatment group, while the activity of LPS was not significantly changed. At the population level, Enterococcaceae were cultured only from the intestines of the A. chinensis in the treatment group. At the genus level, in addition to Serratia, Yokenella and Klebsiella, which were consistent with the control group, the genus Enterococcus was also cultured in the treatment group. When controlling P. rapae in the field, pesticides should be reasonably selected, and an appropriate time should be chosen for the release of A. chinensis to reduce the impact on natural enemies and to achieve synergistic chemical and biological control.

This study investigated the effects of Cryptomeria japonica leaf essential oil (CjLEO) on honey bee health, focusing on both toxicity and gene expression modulation. Initial toxicity assessments revealed that high concentrations of CjLEO (75 and 100 ppm) were lethal to honey bees, resulting in complete mortality within a short period. Conversely, a lower concentration of 10 ppm exhibited no significant toxic effects, prompting further investigation into its sublethal impacts. Transcriptome analysis via next-generation sequencing demonstrated that CjLEO at 10 ppm induced significant changes in honey bee gene expression compared to the control group. Principal component analysis (PCA) and differential gene expression (DEG) analysis identified more than 9,000 genes, with notable upregulation of immune-related genes, including hymenoptaecin, abaecin, and apidaecin1. Gene ontology (GO) enrichment analysis indicated that these differentially expressed genes were primarily associated with immune responses, such as defense and innate immune pathways. The chemical composition of CjLEO, characterized by GC–MS, identified 16 compounds, with major components including α-pinene, elemol, α-eudesmol, and kaur-16-ene. These compounds are known for their antimicrobial properties, which likely contribute to the observed immunomodulatory effects. CjLEO at a concentration of 10 ppm enhances honey bee immunity without exhibiting significant toxicity, positioning it a promising candidate for improving honey bee resilience against pathogens. Future research should investigate the mechanisms of immune activation and optimize application methods for practical beekeeping, aiming to improve colony health while reducing dependence on synthetic chemicals.

In animals, social experience plays an important role in the adaptive modification of behavior. Previous social experience changes locomotor activity in Drosophila melanogaster. In females, suppression of locomotion is observed only when flies are in aggregations, but males retain a reduced level of locomotor activity up to 5 days after being isolated from the group. The mechanisms underlying such behavioral plasticity still largely are unknown. In this study, we aimed to identify new candidate genes involved in the social experience-dependent modification of locomotor activity. We tested the effect of social experience on spontaneous locomotor activity in various mutant males, including those with impaired learning and memory, circadian rhythms, some biochemical pathways, and sensory systems. The results of the present study indicate that the biogenic amines and olfactory perception appear to play key roles in social experience-induced changes in locomotor activity. Also, we performed a screen of the collection of mutants carrying random autosomal insertions of PdL transposon. We isolated five candidate genes, of which two genes, Dek and Hel89B, encode proteins related to the formation of the epigenetic code, implying that epigenetic factors regulating gene expression may be involved in social experience-dependent modification of locomotor behavior.

Remote sensing is being increasingly used in agricultural stress management, offering real-time analysis of crop stress beyond what can be observed visually alone. Hopper burn, induced by brown planthopper (BPH, Nilaparvata lugens) is a significant challenge to rice production in India. This study aims to characterize the spectral reflectance of rice plants with different infestation levels of 2^nd instar BPH nymphs across three varieties namely Pusa Basamti-1509, Pusa Basmati-1121, and TN-1 (susceptible variety to BPH). The differential infestation included 0, 5, 10, 20, 40, 80, 100, 200 number of nymphs. The spectral signatures of the crop were collected at 20 and 40 days after infestation (DAI). The results indicated a distinct change in reflectance pattern between healthy and infested rice plants across all three varieties in green (490–559 nm), yellow (560–584 nm), orange (585–639 nm), and red (640–699 nm) region of visible portion as affected by chlorophyll pigments and in NIR region (700–1800 nm) as affected by cell structure and in water absorption (1915 nm) region of SWIR portion. The specific wavelength band (470, 660,750, 1800, 1915 nm) showing a correlation above 0.8 with pest severity level, was identified as sensitive for assessing BPH damage. Analysis of reflectance changes across wavelengths highlighted that the first derivative has a strong correlation between BPH severity and reflectance in the green region (500–540 nm) and red edge position (680–760 nm). The amplitude of the red edge value decreased with an increase in the severity level of insects. This study identifies the sensitivity of visible and near-infrared regions in detecting and assessing BPH infestation severity.

Biological treatment by black soldier fly larvae (BSFL) has proven to be an effective method for the resource utilization of cyanobacteria, but the effects of microcystin-LR (MC-LR) in cyanobacteria on BSFL growth have not been adequately explored. To evaluate the inhibitory effect and toxic mechanism of MC-LR on BSFL, the growth performance and intestinal microbiota were examined after exposure to 0, 10, 100, and 1000 μg/kg of MC-LR. The larval weight and survival rate were each significantly inhibited by 21.53% and 21.49% compared with the control group, respectively, after exposure at a concentration of 1000 μg/kg MC-LR for 16 days. Lipid accumulation, intestinal inflammation, and oxidative stress were observed in three treatment groups, with dose-dependent inflammation ocurring in the intestine. Compared with the control group, superoxide dismutase and catalase activity levels were significantly increased by 74.91% and 49.58%, respectively, which confirmed the occurrence of oxidative stress induced by MC-LR. Furthermore, MC-LR altered the diversity of intestinal microbiota and increased the relative abundance of pathogenic bacteria (e.g., Paenibacillus, Clostridium_sensu_stricto_1, and Lachnoclostridium), which increased the risk of disease in BSFL and contributed to observed metabolic disorders. On the other hand, qRT-PCR analysis further confirmed the occurrence of oxidative stress and the activation of the peroxisome proliferator-activated receptor signaling pathway, resulting in the upregulation of fatty acid synthesis-related genes, ultimately leading to lipid accumulation and apoptosis. These findings provide valuable insights into the ecological risks associated with MC-LR during the process of cyanobacterial resource utilization.

The aim of this study was to investigate how leaf volatiles from Salix alba affect the orientation of Nematus hequensis Xiao adults towards host plants and contribute to the development of plant-based attractants for N. hequensis. Solid-phase microextraction (SPME) coupled with gas chromatograph-mass spectrometry (GC-MS) was used to extract, identify, and screen leaf volatiles from S. alba aged 10–15 years during the peak eclosion of N. hequensis. Electroantennogram (EAG) and Y-shaped olfactometry assays were utilized to identify volatiles with relative content > 1% and determine the optimal concentration for attracting, 1-day-old unmated males and females. The results showed that among the 15 volatiles with a relative content of more than 1%, (E)-2-hexenal, benzaldehyde, and 2-hydroxybenzaldehyde elicited the strongest EAG response in adult males and females at a concentration of 100 μg·μL^-1, with (E)-2-hexenal exhibiting a greater effect than 2-hydroxybenzaldehyde, which in turn was more effective than benzaldehyde. At this concentration, the attractive effects of (E)-2-Hexenal, and benzaldehyde on adult males and females were significant. These findings provide an important basis for developing attractants and repellents used in control of this insect pest.