Effects of Trichoderma harzianum Rifai and Chaetomium cupreum L.M. Ames on Biological Parameters of Myzus persicae (Sulzer) on Capia-Type Red Pepper (Capsicum annuum L.)

The green peach aphid, Myzus persicae (Sulzer), is a globally important agricultural pest whose management is increasingly challenged by widespread insecticide resistance, prompting interest in alternative and sustainable control strategies such as endophytic fungi. This study evaluated the effects of two endophytic fungi, Trichoderma harzianum and Chaetomium cupreum, applied individually or as a 1:1 mixture, on the population ecology of M. persicae feeding on capia-type red pepper (Capsicum annuum L.). Aphid development, survival, and reproduction were assessed using age-stage, two-sex life table analysis. Contrary to expectations, T. harzianum significantly enhanced aphid population growth, resulting in a higher intrinsic rate of increase (r = 0.42 d^-1), finite rate of increase (λ = 1.52 d^-1), and net reproductive rate (R₀ = 87.67 offspring) compared to the control (r = 0.32 d^-1, λ = 1.37 d^-1, R₀ = 42.90 offspring). The mixture treatment also increased population parameters, whereas C. cupreum showed limited effects on aphid life table traits. Population projections indicated that T. harzianum treatment could produce aphid populations approximately 380 times larger than the control after 60 days. These results suggest that T. harzianum may improve host plant quality in ways that indirectly favor M. persicae. The findings highlight the importance of evaluating plant–fungus–herbivore interactions before incorporating endophytic fungi into integrated pest management programs.