Biological control potential of Trichogramma chilonis (Hymenoptera: Trichogrammatidae) to Phthorimaea operculella (Lepidoptera: Gelechiidae) based on age‐stage two‐sex life table, functional response and mutual interference

Abstract BACKGROUND The potato tuber moth (PTM), Phthorimaea operculella (Zeller) is a significant pest affecting potato crops globally, Trichogramma chilonis (Ishii) is an efficient egg parasitoid with potential for biological control against various lepidopteran pests. We found and identified the Trichogramma chilonis from the parasitized eggs of PTM in the field, but the parasitism and the control potential of Trichogramma chilonis on PTM is unclear. The potential of Trichogramma chilonis to control PTM was evaluated based on the linking age‐stage two‐sex life table, functional response and intraspecific mutual interference effects. RESULTS Trichogramma chilonis performed well on PTM eggs, with females laying 53.98 eggs in a lifetime, the total pre‐oviposition period of 9.24 days, oviposition days of 3.22 days, the high offspring survival rate (0.92), and more females (2.93 females/male). The intrinsic rate of increase, finite rate of increase, net reproductive rate, mean generation time, and population doubling time were 0.328 d −1 , 1.388 d −1 , 36.883 offspring/individual, 10.998 and 2.113 days, respectively. Moreover, Trichogramma chilonis showed a type II functional response to an increase in the number of PTM eggs. The parasitism rate was inversely proportional to the PTM egg density, and the upper limit of the daily attack rate was estimated to be 38.8, with foraging females interfering with each other at higher Trichogramma chilonis densities. CONCLUSION The inclusion of Trichogramma chilonis in a biological control programme for PTM is feasible and has a promising application. © 2025 Society of Chemical Industry.