LAUSR

Abstract Eushistus heros is one of the major pests in soybean in South America. Not only has insecticides constantly failed on its control but also triggered different negative side effects related to the overuse of chemicals. Among the biocontrol agents that can be used in Augmentative Biological Control, Telenomus podisi stands out due to its high parasitism capacity on eggs of its hosts. Therefore, this study aimed to assess T. podisi release strategies and moments (release done together with the detection of first E. heros adults in the area as well as together with fungicide sprays), in order to reach optimal parasitoid field performance. For this purpose, a replicated experiment was conducted with a soybean crop located in Londrina, Parana, Brazil, during 2017/18 and 2018/19 crop seasons. Treatments consisted of 18750 released T. podisi pupae (released either inside cardboard capsules or as unprotected pupae sprinkled in bulk, at different moments) and were evaluated against insecticide spraying strategies. At harvest, yield and quality of the seeds were measured. Overall, our results clearly indicate that T. podisi pupae can be released either encapsulated or unprotected, with similar efficacy. Their release in the field increased E. heros egg parasitism to 70% and 50%, in 2017/2018 and 2018/2019, respectively. Thus, T. podisi can be efficiently used to control stink bug eggs. However, since the number of stink bugs ≥0.5 cm in the field highly depends on its migration from neighboring fields, it is important to use T. podisi inside integrated pest management.