Thermal Requirements of (Hym.: Encyrtidae) and (Hym.: Platygastridae) Parasitizing Eggs (Hem.: Pentatomidae).

Temperature is one of the abiotic factors that strongly influences the biology and behavior of insects. In this study, we assessed the development of egg parasitoids and parasitizing eggs at different temperatures, and estimated the average number of generations for seven representative soybean-producing regions in Brazil. A comparative biology study was conducted, where the percentage of parasitism and emergence, life cycle duration (egg-adult), and longevity were found to be similar between and . The sex ratio and the number of individuals emerged from parasitized egg were higher in in all regions. In the study of thermal requirements, temperatures of 16, 19, 22, 25, 28, 31, and 33 °C were tested. and developed at temperatures between 16 and 31 °C. The base temperature (Tb) for and was 9.3 and 6.7 °C, respectively; the thermal constant (K) was 336.9 and 272.7 degree-days, respectively. The estimated average number of annual generations of both parasitoids was higher than the host. and have the same ability to parasitize and develop in eggs of under the conditions studied. Both parasitoids exhibited satisfactory development and parasitism at temperatures between 19 and 31 °C. The development of both parasitoids was faster than their host, and the number of generations was higher for the seven studied localities.