Host oviposition strategy shapes the parasitism performance and functional response of Telenomus remus.

BACKGROUND: Telenomus remus (Nixon) is a promising egg parasitoid for controlling Spodoptera litura, Agrotis ipsilon, and Helicoverpa armigera. Although this species has been successfully reared under laboratory conditions, we assess how contrasting oviposition behaviors of sympatric noctuid pests influence T. remus performance. RESULTS: We found that T. remus showed a marked preference for the large, cohesive egg masses of S. litura, achieving significantly higher parasitism rates, emergence rates, and female progeny proportions, as well as faster immature development, compared with the small clusters of A. ipsilon and the scattered eggs of H. armigera. Functional-response analyses confirmed its highest attack rate (a = 0.082 h-1) and shortest handling time (Th = 0.55 h) on S. litura. Host egg age reduced performance, but extended exposure improved outcomes. CONCLUSION: These findings reveal that host oviposition behavior is a key determinant of T. remus efficacy and may help inform release timing, duration, and target pest selection, pending field validation. Data are discussed in relation to developing robust, resilient integrated pest management programs to control pests in integrated agriculture. © 2026 Society of Chemical Industry.