Modeling parasitoid development: climate change impacts on Telenomus remus (Nixon) and Trichogramma foersteri...

The egg parasitoids Telenomus remus (Nixon) and Trichogramma foersteri (Takahashi) were recently collected in southern Brazil, expanding their potential use in biological control. Understanding how these species respond to temperature is essential to the effective implementation of biological control programs, especially in the context of global warming. In this study, phenological models were employed to assess the effects of temperature and climate change on their development.

Temperature had a significant impact on the development of Te. remus, with development times ranging from 52.7 days at 15 °C to 8.1 days at 35 °C. Parasitism peaked at 35 °C (124.15 eggs) and lowest at 15 °C (38.5 eggs). Emergence rates declined under extreme temperatures, especially at 15 °C. The Brière-2 and Shi models were identified as the most appropriate for Te. remus and T. foersteri, respectively. Under the SSP2-4.5/2080 scenario, an increase in the number of generations was projected. In contrast, in the SSP5-8.5 scenario, higher temperatures may exceed the thermal thresholds of these species, potentially reducing voltinism in warmer regions while promoting it in colder areas.

Telenomus remus and T. foersteri exhibit broad thermal tolerance; however, extreme temperatures, including those predicted under climate change scenarios, can restrict their development. This study offers valuable insights for laboratory rearing programs, mass production, and field release programs while enhancing the understanding of thermal interactions in Hymenopteran parasitoids. © 2025 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.