Journal of Pest Science最新文献

Frankliniella occidentalis is a serious pest of various plant species and has different olfactory preferences for different host plants. Here, the olfactory responses of female F. occidentalis to the volatiles from different plants (Rosa chinensis, cucumber, and tomato) were tested using electroantennography (EAG) and behavioral bioassays in different types of olfactometers. Y-tube olfactometer bioassays indicated that R. chinensis was the preferred host for F. occidentalis. Fifty-five compounds were identified as components of the volatiles of R. chinensis by gas chromatography–mass spectrometry analysis, of which citronellol (11.62%), 1-hexanol (11.28%), and 3,5-dimethoxytoluene (11.45%) showed the highest relative abundance. EAG recordings showed that antennae of F. occidentalis were able to perceive these three compounds at a wide range of concentrations. In six-arm olfactometer bioassays, F. occidentalis showed significant positive responses to citronellol and 1-hexanol at various concentrations, with the most attractive ones being 10 μg/μL for citronellol and 1 μg/μL for 1-hexanol. When these two compounds at their optimal concentrations were placed in a four-arm olfactometer, significantly more F. occidentalis individuals were attracted to citronellol. F. occidentalis populations were significantly increased under the stimulation of citronellol at 10 μg/μL. Our results show that plant semiochemical volatiles play an important role in the host plant detection and selection of F. occidentalis, and they help guide it to preferred host plants that are suitable for its reproduction. Citronellol showed the greatest potential for development as a novel monitoring and control tool against this thrips species.

While climate change and pesticide use expose insect pests to multiple stressors, their combined effects remain poorly studied. Rising temperatures can accelerate insect life cycles and alter reproductive behaviours, while pesticides can impair physiological functions, reproduction, and survival. Understanding how global warming and pesticide exposure interact is crucial for predicting pest population dynamics and their impact on agroecosystems. As mating behaviour, including mate choice, plays a fundamental role in population growth, studying how these combined environmental stressors influence reproduction is critical. This study investigated how Bordeaux mixture fungicide affects the development, mating behaviour of Lobesia botrana under current (2002–2021) and projected (2081–2100) climatic scenarios. Larvae were reared with two fungicide concentrations and under two climatic conditions. Larval mortality, development time, and adult longevity were monitored. Mating behaviour was assessed using no-choice and choice experiments, measuring pre-mating latency, mating success and duration, fecundity and fertility. Key life parameters (R₀, T, Dₜ, rₘ, and λ) were estimated to investigate population dynamics. Results show that fungicide exposure negatively affected the development and survival of larvae until emergence, but these effects were modulated by climatic conditions. While Bordeaux mixture exposure prolonged development time, future climatic conditions shortened development time compared to current conditions. Choice experiments revealed that under future conditions, moths preferred unexposed partners, whereas no preference was observed under current conditions. These findings emphasize the importance of integrating climate change effects into pesticide risk assessments, as their interactions may have unexpected consequences for pest populations and sustainable management strategies in agroecosystems.

(E)-ß-farnesene (EBF) acts as an alarm pheromone of many aphid species and is also used as an aphid repellent by plants. Upon perception of EBF, aphids exhibit avoidance behavior. They walk away, stop feeding or drop from leaves. Moreover, EBF is an attractant for natural enemies of aphids. However, EBF is not used in pest management because it is expensive in its pure form. Therefore, we assessed the effect of a less expensive farnesene isomer mixture (FIM) on Myzus persicae (Sternorrhyncha: Aphidiae) on lettuce (Lactuca sativa var. Ulmo) in the laboratory and under field conditions. First, we tested under laboratory conditions if FIM has the same effect on M. persicae as it is described for pure EBF. The aphids were influenced by EBF. They stopped feeding, withdrew their stylets, went away from the danger zone, or developed and reproduced more slowly. Therefore, we studied the behavioral response of the aphids after FIM application and aphid reproduction under permanent exposure of FIM. Second, we tested in the field the reaction to FIM either directly applied to lettuce or released by dispensers. In the lab experiments, we found that M. persicae reacts to FIM by walking away and that reproduction tends to be reduced in the presence of FIM. In the field, we found lower numbers of aphids in the treatments with FIM. In particular, dispenser application caused higher aphid reduction compared to spray application on lettuce. In addition, more natural enemies of aphids could be found in dispenser-treated plots. Taken together, these results indicate that the use of FIM could contribute to insecticide-free aphid control in lettuce, but possibly also in other crops.