Behavioral and Reproductive Interactions of Telenomus podisi in Euschistus heros Eggs

• Grant number: 25/02085-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: April 01, 2025
• End date: December 31, 2025
• Field of knowledge: Biological Sciences - Ecology - Applied Ecology
• Principal Investigator: Carolina Reigada Montoya
• Grantee: Gabriela Leite da Silva
• Host Institution: Centro de Ciências Biológicas e da Saúde (CCBS). Universidade Federal de São Carlos (UFSCAR). São Carlos , SP, Brazil

Abstract

During foraging, parasitoid females select high-quality hosts for oviposition to ensure proper offspring development and maximize their fitness. Variation in host age can significantly reduce host suitability, directly affecting parasitism rates and the reproductive success of parasitoids. Given their potential as biological control agents, parasitoid efficiency may be influenced by the host age structure, impacting agricultural pest control. This study will investigate how variation in the egg age of Euschistus heros, a major soybean pest, affects the foraging behavior and parasitism rates of the egg parasitoid Telenomus podisi. Thus, experimental arenas with three interconnected compartments will be used, representing host patches of different qualities, allowing T. podisi females to move freely between them. Two experimental scenarios will be assessed: (i) three patches, each containing six host eggs of specific ages (1, 3, and 6 days); and (ii) three patches with mixed-age eggs (3+3, 3+6, and 3+6 eggs). Over a 30-minute observation period, the time spent in each patch, movement between patches, and the frequency/duration of key behaviors-locomotion, drumming, oviposition, and egg marking-will be recorded. Parasitoid females will remain in the arena for 24 hours before being removed. Subsequently, the number of parasitized eggs, and offspring viability will be evaluated to quantify parasitoid performance across different scenarios. This study aims to provide insights into the foraging behavior of parasitoids, contributing to the optimization of parasitism rates in field releases, particularly in host populations with unsynchronized age structures.