Successful management of Stegasta bosqueella (Lepidoptera Gelechiidae) in peanut with an attract-and-kill strategy.

Abstract

Background: Rednecked Peanutworm Stegasta bosqueella control is primarily achieved using broad spectrum insecticides targeting the larval stage. However, due to inconspicuous behavior and limited movement of the larvae within the peanut crop, foliar insecticides alone have been insufficient to reduce S. bosqueella populations. The poor effectiveness of chemical products, combined with the necessity of frequent fungicide applications, leads to an overuse of pesticides in peanuts. Given the challenges associated with targeting the larval stage, alternative strategies are needed to improve pest management. Our hypothesis was that by targeting the adult stage, the most mobile stage of the insect, we could decrease the levels of S. bosqueella damage in peanut crops while being less aggressive to the environment.

Results: Over 2 years, our study demonstrated that semiochemical-food-based attract and kill treatments significantly reduced the number of S. bosqueella adults captured per food-baited trap per week. This reduction was associated with fewer larvae and decreased plant damage compared to untreated control areas. To optimize this strategy, several key practices must be followed: (a) Prompt treatment application (chemical associated with attractant) should be applied upon detection of an increase in adult trap catches; (b) Timing applications to coincide with peak adult movement (6 pm to 9 pm); and (c) Applying treatments strategically on two peanut rows, 50 m apart, per hectare.

Conclusions: The attract-and-kill method can effectively reduce S. bosqueella damage in peanut crops, and has the potential to target other moth species that act as peanut defoliators. © 2024 Society of Chemical Industry.