Entomologia Experimentalis et Applicata最新文献

Chelonus insularis (Cresson) (Hymenoptera: Braconidae) is an egg-larval parasitoid of the fall armyworm (FAW), Spodoptera frugiperda (JE Smith) (Lepidoptera: Noctuidae). Previous studies reported that maize plants can affect the performance of FAW as well as that of its parasitoids. However, there is little information about whether plants affect the performance of egg-larval parasitoids of FAW. It is also unknown whether C. insularis females can perceive cues from different maize cultivars and therefore preferentially parasitize hosts on which their offspring's performance is highest. In this study, we compared the preference and performance of C. insularis on three maize cultivars: the Mexican landrace Tuxpeño, the inbred B73 from the United States, and inbred isoline B73-lox10, a B73 mutant deficient in the production of jasmonic acid, green leaf volatiles, and herbivore-induced plant volatiles. Oviposition of C. insularis females and colonization preferences of FAW neonate larvae parasitized by C. insularis were assessed using three-choice cage tests in a greenhouse. The offspring sex ratio, adult weight, development time, and longevity were used as indicators of parasitoid performance. C. insularis performance was highest on B73-lox10 plants, lowest on Tuxpeño plants, and intermediate on B73 plants. However, females preferred FAW eggs laid on Tuxpeño plants, followed by those laid on B73-lox10 and B73 plants. FAW neonate larvae parasitized by C. insularis preferentially colonized B73-lox10 plants, although initially they colonized Tuxpeño and B73 plants, which were comparatively detrimental to the parasitoid's development. Overall, C. insularis females did not prefer parasitizing hosts on host plants on which their offspring's performance was highest. However, FAW larvae parasitized by C. insularis chose to colonize host plants on which the parasitoid's performance was highest. The results of this study provide information that could be useful for designing strategies for biological control of FAW.

Urban landscape trees are often faced with pest outbreaks due to insufficient bottom-up and/or top-down regulation. As such, management interventions are frequently needed to keep pest populations under damaging thresholds. Crapemyrtle bark scale (CMBS; Acanthococcus lagerstroemiae (Kuwana), Hemiptera: Eriococcidae) is a non-native insect that commonly reaches outbreak levels in urban areas of the southeastern United States. Augmentative biological control of CMBS using Rhyzobius lophanthae (Blaisdell) (Coleoptera: Coccinellidae) and/or Chrysoperla rufilabris Burmeister (Neuroptera: Chrysopidae) appears to be hampered by low residency and survival of released predators. Here, we investigated whether providing alternative food sources, such as Wheast and/or fructose, could ameliorate these challenges. We first determined if these alternative food sources impact the survival rates of R. lophanthae and C. rufilabris in the presence or absence of CMBS in the laboratory. We then determined if Wheast, CMBS, or crapemyrtle aphids (Tinocallis kahawaluokalani (Kirkaldy), Hemiptera: Aphididae) are attractive to the selected predators using a Y-tube olfactometer. Finally, we measured the residency times of R. lophanthae on CMBS-infested plants provisioned with alternative food sources in the field. Compared with individuals deprived of alternative food sources and prey, C. rufilabris and R. lophanthae lived up to 26 and 8 days longer, respectively, when provided with these food sources. Rhyzobius lophanthae survived the longest on a mixed diet of alternative food sources and CMBS, whereas C. rufilabris lived the longest on a diet supplemented with alternative food sources, regardless of CMBS presence. Neither Wheast nor the various prey items appeared to attract R. lophanthae or C. rufilabris in the laboratory; however, fructose significantly prolonged the residency time of R. lophanthae on CMBS-infested plants in the field. Based on these results, fructose could be incorporated with the release of these two predator species in an integrated pest management program to promote their performance in urban landscapes.

Non-host plant volatiles have demonstrated significant potential in insect behavior manipulation and represent valuable resources for developing alternative pest control strategies. This study investigated the olfactory responses of Corythucha ciliata (Say) (Hemiptera: Tingidae) adult females to volatiles from its host Platanus acerifolia (Aiton) Willd. (Platanaceae) and 23 non-host plants, aiming to identify eco-friendly agents for reducing chemical pesticide reliance. Through four-arm olfactometer bioassays, we revealed that seven non-host species (Metasequoia glyptostroboides Hu & Cheng (Cupressaceae), Liquidambar formosana Hance (Altingiaceae), Broussonetia papyrifera (L.) (Moraceae), Populus tomentosa Carrière (Salicaceae), Chaenomeles sinensis Koehne (Rosaceae), Liriodendron chinense (Hemsl.) (Magnoliaceae) and Fraxinus chinensis Roxb (Oleaceae)) exhibited initial attraction to C. ciliata females compared to clean air. However, when contrasted with host plant volatiles, these non-host emissions lost their attractive effects. Six non-host species (Cedrus deodara (Roxb.) G. Don (Pinaceae), Pinus armandii Franch. (Pinaceae), Pinus bungeana Zucc. ex Endl. (Pinaceae), Platycladus orientalis (L.) Franco (Cupressaceae), Punica granatum L. (Lythraceae) and Cotinus coggygria Scop. (Anacardiaceae)) demonstrated significant repellency. Prior exposure to these repellent volatiles reduced or completely removed such avoidance behavior, but only intermittently. This makes these repellent non-host plants potential candidates as “push” agents in semiochemical-based “push-pull” management systems. This work provides a foundation for developing sustainable control strategies against this invasive pest, currently reliant on chemical interventions in China.

Sweep-netting is widely used for sampling terrestrial arthropods, but specimen extraction is a sensitive step that can introduce biases and variability in ecological or quantitative investigations. Field storage of multiple, independent sweep-net samples, is also usually unfeasible because they need to be chilled, or the specimens immediately transferred to alcohol, to avoid both damage and decomposition. Current extraction methods based on washing and sieving of pooled samples are aimed at qualitative surveys, raising the question of whether direct search, also often used, could be more efficient and reliable for quantitative investigations. This study presents an objective comparison of both methods, investigating Hymenoptera extraction efficiency using direct search versus rapid rinse, a field-adapted variant of traditional rinsing methods designed for use with minimal equipment. Rapid rinse improved specimen recovery by 29%–83% per sample, with only 0.0%–7.6% of specimens missed, compared to 16%–66% missed with direct search. It also yielded 11%–44% more species per sample and reduced processing time by more than half, while maintaining specimen integrity and enabling efficient, stable field storage. Rinsing is therefore recommended as the most reliable and operationally practical extraction method for studies requiring quantitative and comparative accuracy. Rapid rinse adaptations for fieldwork, using just a few items and no assembly, while also resulting in easy storage, improved the technique's overall accessibility.

Biopesticides based on entomopathogenic fungi are considered a potential alternative for controlling stink bug populations in soybean and maize crops. We investigated the susceptibility of immature stages of Euschistus heros (Fabricius, 1974) and Diceraeus melacanthus (Dallas, 1851) (Pentatomidae, Carpocorini) to infections by 30 strains of Beauveria bassiana and Metarhizium spp. In general, Metarhizium spp. strains exhibited a greater capacity to reduce egg hatching and infect nymphs of both E. heros and D. melacanthus compared to B. bassiana. Bioassays with two selected strains, one of each fungal species (M. anisopliae CG1127 and B. bassiana CG1105), demonstrated a 10%–30% reduction in egg hatching compared to untreated eggs of both stink bugs, regardless of egg age (1, 2, or 3 days old). Second-instar E. heros nymphs demonstrated higher susceptibility to M. anisopliae CG1127 infections than fourth-instar nymphs, with ST₅₀ of 5.1 and 5.7, respectively. Furthermore, co-infection assays showed that M. anisopliae CG1127 was more prevalent than B. bassiana CG1105, and no synergistic effect was observed against either E. heros or D. melacanthus nymphs. Adult survival of both E. heros and D. melacanthus after treatment with both strains consistently remained > 80%. Additionally, the number of eggs produced by E. heros females treated with fungal conidia did not differ significantly from the control. Our findings suggest that applications of selected fungal strains should primarily target the immature stages of both stink bug species to optimize biopesticide performance in field conditions.