Journal of economic entomology最新文献

Insect pheromones are critical chemical signals that regulate intraspecific behavior and play a key role in the dynamic monitoring and control of pest populations. Historically, research on insect pheromones has primarily focused on lipid-based compounds. However, terpenes and terpenoids, which are widely occurring classes of bioactive compounds, also play significant roles in insect pheromone blends. Over 50 terpene and terpenoid-based pheromones have been identified in over 52 insect species, spanning various orders such as Coleoptera, Hymenoptera, Blattodea, Hemiptera, Diptera, and Lepidoptera. These compounds are associated with several types of pheromones, including female or male sex pheromones, aggregation pheromones, alarm pheromones, and aphrodisiac pheromones. Terpenes and terpenoids may act as either primary or secondary components of pheromone blends and influence a wide range of critical insect behaviors. They play essential roles in the physiological and ecological adaptation of insects to their environment. This review provides a comprehensive overview of current research on terpene and terpenoid-based pheromones in insects, examining their structures, types, and physiological and ecological functions. Additionally, we propose future research directions to guide the application of these pheromones in insect behavioral regulation and pest management, while advocating for their broader use in insect pest monitoring and control.

Exploring the effects of different solvent extracts from Lepista nuda [(Bull. ex Fr.) Cooke] on the lifespan and reproductive capacity of Drosophila melanogaster (Diptera: Drosophilidae), the extracts of the fruiting body and mycelium of L. nuda were prepared using water, 75% ethanol, and petroleum ether, and the active components were identified. These extracts were then incorporated into culture media and administered to D. melanogaster. The impact of the extracts from different solvents on the life span and fertility, and the contents of ecdysone (20E), juvenile hormone (JH), and vitellogenin (Vg), as well as the effects of autophagy gene, 20E synthesis gene Halloween, 20E receptor gene ECR, JH methyltransferase gene JHAMT and Vg gene Yolk1 transcripts were analyzed. The extracts from the fruiting body and mycelium of L. nuda can reduce lifespan, a phenomenon associated with the varied expression of 15 compounds across 6 distinct groups. The average survival time of female fruit flies was lower than that of the male fruit flies. Fertility had also been significantly reduced, indicating a positive correlation between lifespan and fertility. In addition, with the extension of cultivation time, the content of 20E, JH, and Vg, as well as the transcripts of Halloween, ECR, JHAMT, and Yolk1 in the L. nuda fruiting body extract treatment group, all significantly decreased. Among the 3 solvent extracts, phenylalanine, citric acid, quinic acid, and punicalagin in the L. nuda aqueous extract exhibit the most potent collective toxicity toward fruit flies. The insecticidal properties of these compounds function by modulating autophagy and the expression of insect hormones.

Fungus-growing termites (Termitidae: Macrotermitinae) exhibit significant diversity and abundance in tropical and subtropical ecosystems. Fungus-growing termites consume a wide range of materials, including leaf litter, woody debris, agricultural crops, and wooden structures, including houses. Their presence in termite baiting stations can impede the control of other residential termite pests, such as Coptotermes spp. Current control practices for managing fungus-growing termites are both costly and time-consuming, rendering them impractical for large-scale application. In our review, we analyzed recent biological and control studies on fungus-growing termites to identify key challenges and suggest improvements in termite management strategies. We identified 5 primary factors contributing to the low efficacy of current control measures for fungus-growing termites: (i) sporadic foraging behavior, which diminishes consistent bait intake; (ii) naturally small colony sizes; (iii) the nonmolting nature of the worker caste, reducing the effectiveness of chitin synthesis inhibitors; (iv) fungal cultivation, which delays and mitigates pesticide toxicity; and (v) wide-range of feeding niche, which lessens their consumption of cellulose-based baits. These insights are critical for developing more effective termite control strategies.

The mirid bugs Lygus hesperus (Knight) and L. elisus (van Duzee) are key pests of forage, fiber, and fruit crops. Our goals were to identify pheromone components produced by females of both species and to develop practical pheromone dispensers for use in monitoring these pests. Volatiles collected from virgin female L. elisus contained (E)-2-hexenyl butyrate (E2HB) as the major component with lesser amounts of hexyl butyrate (HB) and (E)-4-oxo-2-hexenal (E4OH) (ratio 117.2:100:17.1, respectively), whereas volatiles and solvent extracts from L. hesperus contained HB and E4OH as major components, with only small amounts of E2HB (100:23.6:3.4, respectively in volatiles). Dispensers fabricated from pipette tips released the components at ~10 µg/d in a ratio similar to the loading ratio. These lures were used to optimize the pheromone blends in field studies from 2012 to 2017. Blends of E2HB and E4OH attracted L. elisus, and a 100:60 blend was optimal. Blends of HB and E4OH attracted L. hesperus, and a 100:60 blend was adopted as a base blend. The additions of possible minor components such as (Z)-3-hexenyl butyrate, (E)-2-hexenal, or 1-hexanol did not improve the attraction of L. hesperus. In trials in alfalfa and strawberry, traps baited with blends of HB:E4OH (100:60) were equally or more effective for monitoring L. hesperus than sweep or vacuum samples, with pipette tip dispensers lasting 2-3 weeks under field conditions. The numbers of L. hesperus captured were lower than expected as compared with reports of pheromone trapping for other Lygus spp. Some possible reasons were investigated.

The papaya mealybug, Paracoccus marginatus (Hemiptera: Pseudococcidae), poses a serious threat to global trade and is classified as a quarantine pest in some countries. Phosphine (PH3) is considered an alternative to methyl bromide for postharvest control of P. marginatus. However, reports addressing the impact of PH3 treatment to control P. marginatus on succulent plants are lacking. This study aims to investigate the effects of PH3 fumigation alone and in combination with ethyl formate (EF) on insecticidal activity across all developmental stages of P. marginatus and its influence on the quality of plant products. Tolerance tests showed that among all developmental stages, the egg stage of P. marginatus is the most tolerant to PH3 treatment. A concentration of 1 g m-3 PH3 for 8 h exposure at 25 °C achieved a 99.9968% (Probit-9) mortality rate for the eggs. Additionally, we examined the synergistic effects of combining EF with PH3. Combined fumigation with 0.5 g m-3 PH3 and 2 g m-3 EF for 8 h at 25 °C did not adversely affect the lifespan and quality of three succulent plant species, achieving an effective dose of 0.99991. These findings suggest that PH3 fumigation, with or without EF, are effective treatments for postharvest control of P. marginatus in succulent plants.

The yellow mealworm, Tenebrio molitor, L., can be an important component of the circular economy because of its ability to transform a variety of agricultural wastes and byproducts into valuable livestock feed. Analysis of their ability to endure toxins coupled with their potential to transfer contaminants to higher trophic levels is not complete. Fumonisins, produced primarily by Fusarium verticillioides (Hypocreales: Netriaceae) (Sacc.) Nirenberg (1976), are mycotoxins likely to be encountered by T. molitor in corn and other grain byproducts. Tenebrio molitor larvae were reared on a simulated diet of corn and other grain byproducts treated with a range of maximum recommended fumonisin B1 levels for different livestock feeds. We observed that T. molitor were able to survive, grow, and reduce by excretion and metabolism their retained fumonisin B1 levels by up to 99.7% compared to the diet they consumed. Unknown metabolic processes were inferred from the significantly reduced content of fumonisin B1 in the frass (63.1% to 73.2%) as compared to the diet and by the first report of long-chain acylated fumonisin B1 derivatives in insect frass.

Invasive species pose a threat to ecosystems and humans worldwide, which is exacerbated by climate change, causing the expansion of species distributions. Ophelimus maskelli (Ashmead) (Hymenoptera: Eulophidae) causes leaf drying and shedding in eucalyptus trees, forming blister-like galls that negatively impact the growth of the trees. Closterocerus chamaeleon (Hymenoptera: Eulophidae) is a recognized parasitoid of O. maskelli. This study used the MaxEnt and CLIMEX models to predict the potential distribution under current and future climate scenarios for O. maskelli and its natural enemy, C. chamaeleon. The MaxEnt model result indicated that isothermality was the most critical factor predicting the distribution of O. maskelli, while the mean temperature of the driest quarter was the most critical factor predicting the distribution of C. chamaeleon. Under current climate conditions, the CLIMEX model predicted a wider potential distribution for O. maskelli and a smaller distribution for C. chamaeleon than the MaxEnt model. MaxEnt and CLIMEX prediction results indicated that South America and Africa were suitable for O. maskelli and C. chamaeleon. The MaxEnt model indicated that under SSP245 climate conditions, the potentially suitable regions for these species expanded, while under the SSP126 climate scenario, the region contracted significantly. The CLIMEX model indicated that under the A1B and A2 climate scenarios, the marginally suitable areas increased, while the moderately and highly suitable areas decreased. This study provides a theoretical basis for creating early monitoring, quarantine, and control methods for invasive pests.

Invasive species pose significant ecological and economic threats globally. Zaprionus tuberculatus Malloch, a drosophilid fruit fly native to the Afrotropical region and Indian Ocean islands, is included in the pest list of the Center for Agriculture and Bioscience (CABI) because it uses fruit as breeding sites and can damage cultivated areas. This fly species extended its range across Europe in the late 20th century; in 2020, it was recorded in South America, and currently, it is widely distributed in Brazil. Here, we assess the potential spreading of Zaprionus tuberculatus in Central and North America based on 2 distinct origins of propagules: from South America and from Europe. To this end, we developed species distribution models using bioclimatic variables and elevation data to project potentially suitable habitats and infer invasion routes. In any case, our results indicate suitability for Z. tuberculatus colonization in Central and North America, including major fruit-producing areas in Central American countries and the United States (Florida and California). The rapid dispersal ability of Z. tuberculatus, coupled with its adaptability to diverse environments, underscores the urgency for proactive monitoring and control measures. Therefore, this study provides valuable insights for developing proactive measures to mitigate the spread of Z. tuberculatus and protect agricultural productivity in the Americas.

Sugarcane borers (SCB) pose a major threat to sugarcane production. Effective pest management requires detailed knowledge of SCB phenology and population dynamics in responses to environmental changes. This study tested the hypothesis that drought drives SCB outbreaks and identified season-specific effects by investigating large-scale field data of these pests in 4 key sugarcane-growing provinces in south subtropical and tropical China (Guangxi, Guangdong, Yunnan, and Hainan) from 1987 to 2018. The standardized precipitation evapotranspiration index was used as a drought indicator at various time scales. We found that drought during a specific month can result in significant changes in the annual SCB outbreak status, such as November in Guangxi, June in Yunnan, and September in Hainan. By summarizing seasonal effects of drought across study locations, we found a general pattern that SCB outbreaks increased with drier conditions in summer, whereas they were promoted by wetter conditions in fall. This research provides crucial knowledge for predicting SCB outbreaks under seasonal and climate changes. This information is also highly critical for increasing the efficiency and accuracy of integrated pest management strategies.