Effect of Trichoderma viride on demographic characteristics of Myzus persicae through capia pepper varieties

The tritrophic effects of Trichoderma viride inoculation on the life table and some biological traits of Myzus persicae using different capia pepper (Capsicum annuum L.) cultivars were investigated under laboratory conditions. Experiments were conducted in adjustable climate chambers under a16-h light/8-h dark cycle, a constant temperature of 25±1 °C and relative humidity. The experiments used the F1 capia pepper varieties 'İmbat', 'HT-70', 'Avşar', and 'Argeto Hilal'. A total of eight experimental groups were created, with and without T. viride application. In the study, data on the development, survival, and reproduction of M. persicae were collected for each experimental group. The pest's demographic parameters were subsequently calculated based on the age-stage-specific two-sex life table theory. Life table parameters were calculated using TWOSEX-MSChart, and population projections were calculated using TIMING MSChart. The findings proved that T. viride inoculation significantly changed the biological periods and population parameters of M. persicae depending on the control group and pepper variety. The highest intrinsic rate of increase (r) and finite rate of increase (λ) of the pest were observed in the control group in the Avsar variety (0.372 day-1) and the lowest in the HT-70 variety (0.299 day-1). Trichoderma viride application statistically significantly reduced the r and λ values in all varieties (e.g., r: 0.372 → 0.322 day-1 in Avşar). Imbat variety was the most affected by T. viride application (r: 0.367 → 0.339 day-1; λ: 1.443 → 1.418 day-1). Life cycle parameters and population projections revealed that T. viride applications were effective at a variety-specific level in pepper varieties, indirectly inducing or suppressing immune systems. These results highlight the need to optimize biological control strategies according to host varieties in integrated pest management programs and offer variety-based recommendations for sustainable agricultural management approaches.