Editor's Choice: May 2025

Thermal performance drifts between the egg-parasitoid Telenomus remus and the fall armyworm may threaten the efficacy of biological control under climate change—M. Mubayiwa, H. Machekano, B. M. Mvumi, W. A. Opio, B. Segaiso, F. Chidawanyika, & C. Nyamukondiwa (https://doi.org/10.1111/eea.13557). Thermal performance drifts between the egg-parasitoid Telenomus remus and the fall armyworm may threaten the efficacy of biological control under climate change—M. Mubayiwa, H. Machekano, B. M. Mvumi, W. A. Opio, B. Segaiso, F. Chidawanyika, & C. Nyamukondiwa (https://doi.org/10.1111/eea.13557). Climate change is a major threat to ecosystems as it may cause niche shifts of interacting species. Global warming may alter host–parasitoid interactions, rendering biological pest control less effective if the pest and control agents respond differently to temperature change. Mubayiwa and colleagues investigate various thermal response parameters of the egg parasitoid Telonomus remus (Hymenoptera: Scelionidae), a promising biocontrol agent of the fall armyworm, Spodoptera frugiperda (Lepidoptera: Noctuidae). Exposure to high temperature (32°C) increases the parasitoid's heat tolerance but reduces its cold tolerance. However, more worrisome is the simultaneous heat exposure of the fall armyworm eggs, which reduces their parasitism rate and adult emergence rate. These results indicate that in warming regions, the parasitoid may lose out, potentially resulting in less effective pest control. Of course, longer term negative effects of climate change remain to be demonstrated under field conditions, where natural selection operates, and the parasitoid will have the opportunity to evolve.