Insects最新文献

Since local egg production using Pasteur's method began in 1895, two local silkworm breeds have mostly been reared in Bulgaria, namely, Yellow local and White Baghdad. The Yellow local breed is said to have originated and been reared from local breeds spread in northern and southwestern Bulgaria in the 16th-19th centuries, while White Baghdad originated from Asia Minor and was reared in southeastern Bulgaria. The Yellow local breed is characterized by yellow cocoons with an elongated shape with slight constriction. The white Baghdad breed consists of three types, namely the Edirne, Improved Bulgarian, and Bulgarian types. The cocoon color varies from snow white to light green, but the prevailing color is white. The cocoon shape is elongated, with constriction. The old silkworm breeds reared in 1920s-1930s Bulgaria were generally characterized by a non-uniformity of larval color and markings, as well as of cocoon color and shape, with comparatively high cocoon weights but lower silk shell percentages and filament lengths; they were also comparatively tolerant to NPV disease. Due to the long maintenance of these breeds in Bulgaria, they have become well adapted to the local food and climatic conditions. Presently, the Yellow local strain displays high hatchability and survivability, shorter fifth-instar duration, and a comparatively good reproduction capacity. On the other hand, it manifests lower values of main productive characteristics, such as cocoon weight, silk shell weight and percentage, silk filament length and weight, reelability, and raw silk percentage as compared with commercial Bulgarian white-cocoon breeds. Therefore, in order for this breed to be commercialized today, it needs to be improved by way of genetics and breeding. This paper includes a review of the literature on the inheritance of main qualitative characteristics in silkworms, as well as recommendations for future studies on improving old silkworm breeds.

Camellia oleifera, commonly known as oil-tea, serves as one of China's most economically important oil crops. To ensure continued production yield and quality, biological control measures, operating within the framework of integrated pest management, have been extensively adopted nationwide. Integrated pest management facilitates effective management of arthropod pests afflicting C. oleifera by integrating biological control strategies with traditional chemical control methods. This approach significantly reduces the reliance on chemical pesticides and minimizes adverse environmental impacts. Over 600 natural enemy species targeting pests have been documented within the C. oleifera agroecosystems in China including approximately 38 viral agents along with 41 fungal, 166 parasitoid, 336 predator, and several bacterial species. Notably, both insectile natural enemies and fungal biopesticides derived from microbial resources are currently being used at scale in C. oleifera cultivation regions, serving as crucial alternatives to the use of conventional chemical pesticides. This paper comprehensively reviews recent progress in research and the application of synergistic integration of biological control with traditional pest management strategies for C. oleifera. The current status of research on natural enemy resources is analyzed and knowledge gaps in the domain of C. oleifera pest management are identified. Furthermore, future research trajectories are proposed that are intended to provide a scientific basis for the green and sustainable development of the C. oleifera industry.

Morpho butterflies have the potential to act as a bioindicator species, since they are sensitive to changes in land uses and forest degradation; there have been few population studies of butterflies in the Caribbean region of Colombia. In this study, we aimed to analyze and characterize the population structure of M. helenor peleides and evaluate its variation across different land uses. We used the capture-mark and release technique, with 50 VanSomeren-Rydon type traps distributed in five sampling units with different land uses (forest, restoration areas, and pasture areas); temperature and luminosity were also measured. Butterflies were wing-marked and subsequently released. Sampling was carried out between June and September 2023. Jolly-Seber population models were constructed using the R code to obtain population size (N_i), survival rate, and recruitment; also, other parameters were analyzed (abundance of the imagines, average sex ratio-ASR, displacement, permanence, and age). A total of 876 butterflies were tagged and released, and 33.7% were recaptured. Butterfly abundance was concentrated in conserved sampling units in the forest. The N_i ranged from 25 to 845 individuals within the population, and individual displacement and permanence were restricted in the forest, ASR was significantly male-skewed. The land use directly influenced the population structure of M. helenor peleides, suggesting that conserved areas are key to population persistence.

Understanding how insects adapt to temperature is crucial to elucidating the ecological factors shaping their life history traits. Phenological models are influenced by temperature, allowing researchers to examine how temperature affects population dynamics, geographical distribution, and the management of various insect species. This study was conducted at seven constant temperatures (15.3, 20.8, 25.0, 27.0, 30.1, 35.0, and 40.0 °C) under temperature-controlled conditions in an incubator to assess temperature-dependent development of D. baccarum. Clusters of eggs were put into Petri dishes and kept in a humidity chamber. The humidity chamber was then placed inside the incubator. Temperature affected the developmental parameters and mortality of D. baccarum reared on sesame seed pods. Stage-specific parameters, including the lower developmental threshold (LDT) and thermal constant (K, in degree days [DD]), were estimated using linear (GLM) and nonlinear (Lactin2) models, respectively. Total development time from egg to adult decreased with increasing temperature. Successful development occurred between 20.8 and 35.0 °C, and failed under 15.3 and 40.0 °C (100% nymph mortality). Egg stage duration ranged from 30.56 days at 15.3 °C to 2.07 days at 40 °C, while nymphal development ranged from 64.75 days at 20.8 °C to 21.17 days at 35.0 °C. The estimated LDT and K-values were 14.22 °C and 492.22 degree days (DD), respectively. Based on these thermal requirements, we developed a predictive model to better understand population dynamics and inform pest management strategies, which can help predict the spring occurrence, number of generations, and population dynamics of D. baccarum.

Acoustic detection technology has emerged as a promising, non-destructive and continuous monitoring method for pest early detection at the single tree level. However, field application still encounters problems, especially under complex infestation scenarios, i.e., co-infestations by multiple pest species. This study aims to develop a novel acoustic-based recognition model for detecting forest wood-boring pests, specially designed to enhance monitoring accuracy under complex infestation scenarios. We collected feeding vibration signals from four wood-boring pests: Semanotus bifasciatus, Phloeosinus aubei, Agrilus planipennis, and Streltzoviella insularis. Three infestation scenarios were designed: single-species, co-infestation without mixed signals, and co-infestation with mixed signals. Three machine learning (ML) models (Random Forest, Support Vector Machine, and Artificial Neural Network) based on seven acoustic feature variables, and three deep learning (DL) models (AlexNet, ResNet, and VGG) using spectrograms were employed to classify the signals. Results showed that ML models achieved perfect accuracy (OA: 100%, Kappa: 1) in single-species scenarios but declined significantly under co-infestation scenarios with mixed signals. In contrast, DL models, particularly ResNet, maintained high accuracy (OA: 85.0-88.75%) and effectively discriminated mixed signals. In conclusion, this study demonstrates the superiority of spectrogram-based DL models for acoustic detection under complex infestation scenarios and provides a foundation for developing a general, real-time detection model for integrated pest management in forest ecosystems.

Purple maize and canary beans are economically important crops in Peru, grown for domestic and international markets. However, postharvest storage losses are a major challenge along the value chain due to insect pests. This study evaluated the efficacy of the Purdue Improved Crop Storage (PICS) and polypropylene (PP) bags in storing both crops in the Arequipa region, Peru. Oxygen and CO₂ levels were monitored every month. Insect pests, germination rates, sugar content, peroxide index, moisture content, and colony-forming units (CFU) were measured at the start and nine months after storage to determine the level of grain deterioration. PICS maintained a hypoxic environment that suppressed insect development and limited grain damage and weight loss to below 1%. In contrast, PP bags allowed infestations to escalate, resulting in weight losses of about 20% for each crop. Germination declined markedly in PP for both crops; in PICS, it remained high for purple maize (87.5%) but fell substantially for canary beans (20.8%). Moisture rose modestly in PICS, yet deterioration markers, including sugar content and peroxide index, were lower than in PP bags. Although Fusarium, Aspergillus, and Penicillium were detected in purple maize across both systems, mold loads were far lower in PICS. Overall, hermetic storage in PICS bags is effective in reducing postharvest losses and preserving important quality characteristics of beans and maize in Peru.

Amygdalin, or vitamin B17, has attracted attention due to its commercial promotion as an anticancer and immune-boosting agent, despite documented concerns regarding its potential toxicity. To address this controversy, the present study demonstrates the protective effects of vitamin B17 against the harmful effects of ultraviolet radiation (UVR), a major risk factor for skin cancer, using the model organism Drosophila melanogaster. Our results showed that vitamin B17 supplementation effectively mitigated the adverse effects of UVR. Flies fed B17-supplemented food prior to UVR exposure displayed markedly higher adult emergence rates, improved climbing ability and shortened developmental time compared to UV-exposed flies on standard food. At the cellular level, B17 supplementation reduced Caspase-3 activation, preserved the structural integrity of compound eyes and mitochondria. Furthermore, biochemical analysis revealed that vitamin B17 reduced levels of oxidative stress markers, such as malondialdehyde, while simultaneously enhancing the activity of antioxidant enzymes, such as superoxide dismutase and catalase. Overall, these results demonstrate that vitamin B17 protects against UV-induced adverse effects in adult flies, highlighting its potential as a modulator of environmental stressors. However, caution is warranted given its known toxicity profile, which warrants further studies to determine appropriate doses and potential toxicity to other organisms.

Widely used in humans and animals for bacterial infection management, antibiotics are poorly absorbed and persistent, being excreted into ecosystems and causing serious pollution. However, the effects of extended exposure to residual environmental levels of antibiotics in fireflies are currently unknown. In this study, we investigated Aquatica leii growth and development under chronic low-dose exposure to oxytetracycline (OTC) and levofloxacin (LEV) residues using physiology, transcriptomics, and metabolomics. The results showed that OTC and LEV treatments enhanced A. leii larval growth (increased body length and weight) and significantly altered SOD and CAT activities. Transcriptional analyses identified 1193 and 1669 differentially expressed genes from the LEV and OTC groups, respectively, compared to the control group, predominantly associated with insect hormone biosynthesis, digestive system, immune system, and signal transduction. The metabolomic results showed that 965 and 1094 endogenous metabolites (i.e., comprising mainly amino acids, organic acids, and carbohydrates) were affected by LEV and OTC treatments, respectively. These metabolites are mainly enriched in signal transduction, amino acid metabolism, and energy metabolism pathways. Further, a conjoint omics analysis highlighted the multifaceted regulatory roles of glutathione metabolism in the response of A. leii to OTC and LEV treatments. The study provides critical insights into the transcriptional and metabolic responses of A. leii to antibiotic treatment, informing dosage guidelines for sustainable A. leii farming.

Gut microbial community research has garnered considerable attention due to its pivotal role in shaping diverse insect hosts' life-history traits, with key studies confirming that insect gut microbiota is vital for core physiological processes including growth, nutrient metabolism, nitrogen fixation, pheromone biosynthesis, and environmental adaptation. Findings highlight that integrating insect ecology understanding with gut microbial community characterization is indispensable for innovative pest management strategies. Notably, S. frugiperda, a globally destructive agricultural pest causing substantial annual economic losses, has been extensively investigated. Its host range is extremely wide, from staple food crops such as corn and rice to various cash crops. This review systematically synthesizes the prevalent diversity of its gut's dominant microbes, clarifies the important mechanism of gut microbiota in host stress adaptation (providing direct evidence for explaining the pest's stress resistance formation), draws the key conclusion that host-microbe interaction mechanisms can serve as key pest management targets to guide more targeted control technologies. We also discuss current limitations such as inadequate microbial function verification and unclear host-microbe molecular mechanisms while outlining future directions including focusing on microbial community dynamic changes under multiple environmental stresses and functional microbe screening and application.

Plant volatiles play a critical role in mediating insect host location behavior and offer eco-friendly alternatives for chemical control. Monolepta signata is a widespread phytophagous pest in East Asia that poses a significant threat to various crops. In this study, we evaluated the electrophysiological and behavioral responses of adult M. signata to 26 binary and ternary mixtures of 13 plant-derived volatile compounds extracted from cotton and corn leaves. Electroantennogram (EAG) recordings revealed that females exhibited the strongest responses to mixtures 20, 23, and 12, whereas males were the most responsive to mixtures 26, 19, and 4. Y-tube olfactometer assays showed significant behavioral attraction of females to mixtures 1, 20, 23, and 26, and males to mixtures 19, 22, and 23. Field trials demonstrated that mixtures 22, 23, and 26 attracted significantly more adults than the control, with mixture 23 (α-phellandrene + trans-2-hexen-1-ol + 1-heptene) achieving the highest trap capture. These findings highlight the potential of specific volatile blends, especially ternary mixtures, as effective attractants of M. signata, and support their application in environmentally sustainable pest monitoring and management strategies.