Search Results (240)

In Qinghai Province, Evergestis extimalis is an important pest of spring rape and is primarily controlled using chemical pesticides. Sex pheromones offer an alternative method for pest management in relatively non-polluted environments. In this study, the sex of E. extimalis pupae was identified, followed by isolation and structural characterization of female pheromone components using GC-EAD and GC-MS. A field attraction assay was then performed. The results showed that female pupae possess a longitudinal crack on the upper central ventral surface of the eighth abdominal segment, which connects the seventh and ninth abdominal segments. The two sides of this crack are open and flat, without protruding semicircles. Male pupae lack this longitudinal crack on the eighth abdominal segment but display one on the central ninth ventral segment, accompanied by semicircular tubercles on each side. The primary component extracted from female sex glands was identified as E11-14Ac. In field trials, E11-14 displayed a stronger attractive effect on E. extimalis males than the other tested attractants. In conclusion, E11-14Ac was preliminarily identified as the main component of the sex pheromone of E. extimalis, providing a foundation for its control using sex pheromones. Full article

The courtship behavior of moths is closely related to the biosynthesis and release of sex pheromones. To understand the mechanisms of the reproductive behavior of the ghost moth Endoclita davidi, a host insect of Cordyceps xuefeng (Ophiocordyceps xuefengensis), this study examined the courtship behavior and the ultrastructure of the sex pheromone gland of E. davidi. Infrared photography was used to analyze the courtship behavior, while SEM, paraffin tissue sectioning, and TEM were employed to examine the sex pheromone glands on the hind tibia. The courtship behavior of E. davidi occurs during the scotophase, during which males vibrate their wings and unfold the hairpencils located on the hind tibiae to lure the female moths. The hairpencil’s surface features regular longitudinal ridges interspersed with multiple circular pits. Multiple small holes were evident on the slightly enlarged areas close to the ends of the hairpencils. These small holes, formed at the base of the circular pits, connect to the internal glandular duct within the hairpencil, which links to the tibia glandular canal. The epidermal layer of the hind tibiae contains numerous glandular canals and dense microvilli. The glandular cells, specialized from dermal cells, contain numerous mitochondria, rough endoplasmic reticulum, clear vesicles of varying sizes, and round lipid droplets. The sex pheromone glands of male E. davidi release pheromones through the hairpencils in the hind tibia. The courtship behavior and ultrastructure of the sex pheromone gland of the male E. davidi provide a basis for further understanding pheromone release and communication mechanisms. Full article

Most assessments of sex pheromone-based mating disruption (MD) for codling moth (CM), Cydia pomonella (L.), have not included measurements of female mating. The recent development of a dual-sex lure (CM4K) combining ethyl (E,Z)-2,4-decadienoate, 4,8-dimethyl-1,3,7-nonatriene, pyranoid linalool oxide, and acetic acid has significantly increased the catch of female CM and made it easier to directly assess various MD programs. Samples of wild female CM populations using this lure were collected from 142 orchards, either untreated or treated with one of seven different dispenser systems for CM MD, from 2021 to 2022. The proportion of unmated females ranged from <0.20 to >0.80 with a median of 0.43 in both years. No differences in the mean proportion of unmated females were found between apple and pear. Moth immigration and supplemental insecticide sprays were hypothesized to be key factors affecting the variability within each MD tactic. Mating levels were significantly higher later in the season. More females were unmated in conventional compared with organic orchards. Means for females not mating among the CM MD programs varied over a 0.20 range, except for one. The exception occurred when two MD tactics (aerosol units plus hand-applied dispensers) were accidentally used together, and the proportion of unmated females was significantly higher. Full article

Globally, Spodoptera frugiperda is a major threat to many important crops, including maize, rice, and cotton, causing significant economic damage. To control this invasive pest, environmentally friendly pest control techniques, including pheromone detection and identification of potential molecular targets to disrupt S. frugiperda mating communication, are needed. Female moths biosynthesize pheromones and emit them from the pheromone gland, which significantly depends on the intrinsic factors of the moth. Male S. frugiperda have a sophisticated olfactory circuit on their antennae that recognizes pheromone blends via olfactory receptor neurons (ORNs). With its potential to significantly modify the insect genome, CRISPR/Cas9 offers a revolutionary strategy to control this insect pest. The impairing physiological behaviors and disrupting the S. frugiperda volatile-sensing mechanism are the main potential applications of CRISPR/Ca9 explored in this review. Furthermore, the release of mutant S. frugiperda for their long-term persistence must be integral to the adoption of this technology. Looking forward, CRISPR/Cas9-based gene drive systems have the potential to synergistically target pheromone signaling pathways in S. frugiperda by disrupting pheromone receptors and key biosynthesis genes, thereby effectively blocking intraspecific communication and reproductive success. In conclusion, CRISPR/Cas9 provides an environmentally friendly and revolutionary platform for precise, targeted pest management in S. frugiperda. Full article

Insects rely heavily on olfaction to regulate essential behaviors such as host location, oviposition and mating. The invasive cotton mealybug, Phenacoccus solenopsis Tinsley represents a global threat to cotton and numerous cultivated crops. To elucidate the molecular basis of its olfaction mechanisms, we sequenced and assembled antennal transcriptomes from male and female adults using Illumina NovaSeq X Plus technology. Among 13,891 unigenes, 91 chemosensory genes were identified, including 40 odorant receptors, 13 gustatory receptors, 19 ionotropic receptors, 10 odorant-binding proteins, 7 chemosensory proteins, and 2 sensory neuron membrane proteins. Differential expression analysis revealed 6312 genes with significant sex-biased expression between male and female antennae, including 55 chemosensory genes. Phylogenetic analyses further clarified the evolutionary relationships of these chemosensory genes with homologs from other hemipteran species. Notably, validation confirmed that 18 PsolORs were male-biased. This comprehensive transcriptomic study establishes a foundation for further functional characterization of pheromone reception and provides valuable candidate genes for dissecting chemoreception mechanisms in P. solenopsis. Full article

The fall webworm Hyphantria cunea (Lepidoptera: Erebidae) is a globally invasive species that causes serious damage to agriculture and forestry. Since the first invasion reported in Liaoning Province, China, it has spread extensively southward and was found in Shanghai in 2019. Owing to the climatic and environmental differences between these regions, the biology and population dynamics of H. cunea may have undergone changes in its newly invaded areas. In this study, we investigated the biology of H. cunea in Shanghai and monitored the population dynamics using sex-pheromone-baited traps. We analyzed the relationships between population dynamics and local meteorological factors, including temperature, precipitation, and sunshine duration. Our result indicates high temperatures and large diurnal temperature ranges have significant effects (R² = 0.723, p < 0.001) on the survival and development of H. cunea. Consequently, they play an important role in shaping its population dynamics. These findings enhance our understanding of how H. cunea responds to Shanghai’s environmental conditions, provide a scientific basis for local pest management, and contribute to predicting its population trends. Full article

The western hemlock looper, Lambdina fiscellaria lugubrosa (Hulst) is a destructive defoliator of coniferous forests and a major cause of economic losses in forestry. A novel and efficient stereoselective synthesis of the sex pheromone of the western hemlock looper (1, 2 and 3) has been successfully achieved. The synthetic strategy integrates several key transformations, including Evans’ chiral auxiliaries, Grignard cross-coupling, hydroboration–oxidation, sulfone alkylation, and hydrogenation, providing an efficient and scalable approach for sex pheromone production. The three synthesized pheromone components were subsequently tested for their ability to attract Semiothisa cinerearia (Bremer & Grey) using both Y-tube and cage bioassays. Notably, compound 1 exhibited a cross-species attractive effect on S. cinerearia, a species that had not previously been documented to respond to the pheromone of L. fiscellaria lugubrosa. This discovery underscores the potential for cross-species attraction, broadens our understanding of pheromone specificity, and emphasizes the value of stereoselectively synthesized pheromones as molecular tools for cross-species pest monitoring and integrated pest management. Full article

IPM approaches based on pheromone-based techniques for the management of the South American tomato pinworm, Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae), are of great interest. We evaluated the effectiveness of mating disruption (MD) experiments against T. absoluta using a biodegradable pheromone dispenser (Isonet-T TT BIOX234) in greenhouse-grown tomatoes over two years in southern Italy. A base treatment alternating the most used insecticides for the pest, i.e., the farmer treatment schedule (FTS), was assigned as a reference, and two MD dispenser densities (i.e., 300 and 500 dispensers/ha) were compared with the MD commercial product Isonet T at 1000 units/ha. We conducted two trials on crops at a density of 37,000 plants/ha. Pest flights were monitored in summer–autumn 2023 and 2024 with pheromone-baited Delta traps. The FTS ensured a generally low level of T. absoluta attacks (about 1 leaflet/leaf and 1/300 fruits). Even so, mating disruption resulted in further appreciable reductions in the presence and attacks of the target pest: 89%, 76% and 52% fewer catches; 61%, 45% and 37% fewer mined leaflets; and 76%, 59% and 54% fewer attacked fruits, for Isonet-T TT 500, Isonet-T TT 300 and Isonet T 1000, respectively. Overall, MD biodegradable dispensers could be a valuable tool for controlling T. absoluta in greenhouse-grown tomatoes, while also reducing plastic waste in the agricultural setting. Full article

Insects use chemical compounds to communicate with conspecifics and other organisms. The corn leafhopper, Dalbulus maidis (Hemiptera: Cicadellidae) (DeLong & Wolcott), is an important pest in Brazilian maize crops due to its role as a vector of phytopathogens. Despite its economic importance, the chemical communication between sexes in this species remains to be elucidated. This research aimed to unveil whether D. maidis produces chemical compounds that influence the behavior of the opposite sex and may act as sex pheromones. To evaluate the influence of these volatiles, olfactometer bioassays were conducted as dynamic headspace volatile collections from live insects. Results showed that both male and female leafhoppers emit volatile compounds; however, no sex-specific compounds were detected. Females were attracted to male odors and male aeration extracts, suggesting males produce sex-specific volatiles. Interestingly, males avoided odors from non-acclimated females, which may indicate possible alarm pheromone release. Although the compounds were not identified, this is the first study to demonstrate intraspecific chemical communication in D. maidis mediated by volatiles, and the first such record in Membracoidea. These results contribute to understanding the pest’s biology and support the development of monitoring and control strategies in maize crops. Full article

Comparative experiments on trapping major rice pests using different methods showed that a light-transmitting three-combination trapping method, using different combinations of color plates + insect sex pheromones + transmitting (shielding) light covers + solar-powered automatic insect-attracting ultraviolet lamps, demonstrated significant positive attraction and synergistic effects on the simultaneous capture of multiple pests, including rice Sogatella furcifera, Laodelphax striatellus, Chilo suppressalis, and Sesamia inferens and rice leafhoppers, Sitobion miscanthi, Cnaphalocrocis exigua, Parnara guttata, and Naranga aenescens. In addition, the light-transmitting three-combination trapping method has a low benefit-harm ratio and is not easily disturbed by non-target flies (Muscadomestica). The ultraviolet light and transmitting cover in the device had a negative effect on attracting the Cnaphalocrocis medinalis, resulting in a highly significant or significant decrease in its capture rate. The results also showed that the light-shielding double-combination trapping method, which lacks ultraviolet lamp waves and transmitting covers, had no significant difference in the capture rate and insect benefit-harm ratio of C. medinalis adults compared with the glue-type sex lure method, confirming that C. medinalis has a significant negative tendency characteristic to ultraviolet lamp waves and transmitting covers. Therefore, the light-shielding double-combination trapping method using color plates and insect sex pheromones is recommended for monitoring the weakly phototactic C. medinalis. The light-transmitting three-combination trapping method is preferred for the simultaneous capture of multiple major rice pests besides C. medinalis. This study provides a scientific basis for the rational and effective application of multi-source physical and chemical trapping for monitoring and pest control of major crop pests. Full article

Spodoptera frugiperda is a major transboundary migratory pest under global alert by the Food and Agriculture Organization (FAO) of the United Nations. The accurate identification and counting of trapped adults in the field are key technologies for achieving quantitative monitoring and precision pest control. However, precise recognition is challenged by issues such as scale loss and the presence of mixed insect species in trapping images. To address this, we constructed a field image dataset of trapped Spodoptera frugiperda adults and proposed an improved YOLOv5s-based detection method. The dataset was collected over a two-year sex pheromone monitoring campaign in eastern–central Yunnan, China, comprising 9550 labeled insects across six categories, and was split into training, validation, and test sets in an 8:1:1 ratio. In this study, YOLOv7, YOLOv8, Mask R-CNN, and DETR were selected as comparative baselines to evaluate the recognition of images containing Spodoptera frugiperda adults and other insect species. However, the complex backgrounds introduced by field trap photography adversely affected classification performance, resulting in a relatively modest average accuracy. Considering the additional requirement for model lightweighting, we further enhanced the YOLOv5s architecture by integrating Mosaic data augmentation and an adaptive anchor box strategy. Additionally, three attention mechanisms—SENet, CBAM, and Coordinate Attention (CA)—were embedded into the backbone to build a multidimensional attention comparison framework, demonstrating CBAM’s superiority under complex backgrounds. Ultimately, the CBAM-YOLOv5 model achieved 97.8% mAP@0.5 for Spodoptera frugiperda identification, with recognition accuracy for other insect species no less than 72.4%. Based on the optimized model, we developed an intelligent recognition system capable of image acquisition, identification, and counting, offering a high-precision algorithmic solution for smart trapping devices. Full article

Background: Grassland desertification has garnered significant attention as a pressing issue. Among the key pests affecting plateau meadows, the Gynaephora qinghaiensis (Lepidoptera: Lymantriidae) poses a substantial threat in the Qinghai-Tibet Plateau region, highlighting the urgent need for effective, environmentally friendly control strategies. Insect sex pheromones are increasingly employed in pest monitoring and management. Methods: This study aims to identify and analyze genes associated with sex pheromone synthesis in grassland caterpillars through transcriptome sequencing and tissue-specific expression analysis. Results: A total of 139,599 transcripts and 56,403 Unigenes were obtained from the sex pheromone glands transcriptome database. A total of 31 genes related to sex pheromone synthesis were identified, including 1 ACC, 8 DES, 6 AR, 7 FAR, 5 FAS, and 4 ACT genes. The expression levels of these genes varied significantly across different tissues in both male and female caterpillars (p < 0.05). GqinACC1, GqinDES1, GqinDES4, GqinDES8, GqinAR3, GqinFAR6, GqinACT2, and GqinACT3 exhibited significantly higher expression levels in the female gonads compared to other tissues (p < 0.01). Conclusions: We hypothesize that specific genes play specific roles in the pheromone synthesis pathways of pests, Key genes were identified based on expression patterns for subsequent functional studies. The results of this study offer valuable data support for subsequent investigations into the mechanisms underlying sex pheromone synthesis in G. qinghaiensis. Additionally, these findings may identify potential targets for future research on genes associated with pheromone biosynthesis, which could disrupt their chemical communication and contribute to grassland conservation efforts. Full article

Sex pheromones and semi-synthetic bisexual lure (SBL) were used both in parallel and in combination within single traps to monitor four widely distributed noctuid pest species. For Agrotis ipsilon, the SBL proved to be more effective than the species-specific sex pheromone, and it can be used alone instead of them, as well as for monitoring the pest. In the case of A. segetum and Lacanobia oleracea, the lures did not inhibit each other, and their parallel and combined use provided a more accurate representation of swarming dynamics and abundance peaks, as well as enabled the monitoring of female flight activity. Observations revealed shifts in the life cycle of L. oleracea and further supported the migratory nature of A. segetum. The parallel and combined application of the newly developed SBL and conventional sex pheromone lures may significantly enhance the precision of pest monitoring and forecasting, thereby supporting more precise planning and timing and more effective implementation of plant protection treatments in IPM strategies. Full article

Many cases have been described where the combination of semiochemicals and light sources in traps cause an increase in adult insect attraction. In this context, we tested different treatments using Delta plastic traps to catch DBM adults: (1) dispensers containing DBM SSA; (2) UV (365–370 nm) LEDs; (3) a combination of a dispenser containing DBM SSA and LEDs (SSA + LED); and (4) no lures (Control). The trials were conducted in northwestern Russia (the vicinity of St. Petersburg) during the period of 2022–2024 on cabbage crops. The results showed a highly significant interaction between SSA and LEDs with respect to their attractiveness to male DBM adults, as evidenced by an average 15-fold increase in DBM captures after the traps containing SSA were equipped with a second lure, an LED. This article discusses the prospects for using the identified synergistic effect of interaction between SSA and LEDs to enhance the catch of DBM adults for practical purposes, such as improving monitoring and developing more effective mass-trapping technologies. Full article