Exploiting the 'ecology of fear': volatile-mediated disruption of moth development and reproduction by a mite...

The intricate ecological interplay between predators, prey, and parasitoids is a key determinant of ecosystem dynamics. This study investigates the non-consumptive effects of the mite parasitoid Pyemotes zhonghuajia on the potato tuber moth (PTM) Phthorimaea operculella, revealing complex responses within the framework of the 'ecology of fear'.

The results show that PTM exhibits accelerated development and a shortened lifespan in the presence of P. zhonghuajia, particularly during the larval stage. Additionally, parasitoid exposure significantly impacts PTM's reproductive parameters, leading to reduced fecundity. Gas chromatography-mass spectrometry (GC-MS) analysis identified 34 volatile compounds emitted by P. zhonghuajia. Electroantennography (EAG) recordings revealed that PTM antennae responded to most of these volatiles, with males generally exhibiting higher sensitivity than females. In Y-tube olfactometer bioassays, females showed no behavioral response to any of the tested compounds, whereas males were attracted to decanal, 2-undecanone, nonanal, tetramethylpyrazine, and trimethylpyrazine.

These fear-induced responses underscore the delicate trade-off between survival and reproduction in host species facing parasitism risk. The study highlights the ecological implications of such fear-driven alterations in host life history traits and olfactory behavior. Furthermore, the findings provide valuable insights into the potential application of P. zhonghuajia as a biocontrol agent against PTM. Understanding these mechanisms contributes to the development of sustainable integrated pest management (IPM) strategies, promoting ecologically balanced pest control in agroecosystems. © 2025 Society of Chemical Industry.