Biological and population parameters of Telenomus remus and Trichogramma atopovirilia as biological control agents for Spodoptera frugiperda

Abstract

Maize production faces a significant threat from Spodoptera frugiperda (J. E. Smith) worldwide; historically, Trichogramma pretiosum Riley has served as the primary augmentative egg parasitoid for its biological control. However, since 2004, Telenomus remus Nixon has emerged as a viable global alternative. On a regional scale, in Mexico, Trichogramma atopovirilia (Oatman & Platner) was theorized to outperform T. pretiosum, proving superior in both laboratory and field conditions in 2020. To further the field efficacy of the augmentative use of parasitoids as biological agents of S. frugiperda, we conducted comparisons of biological and population parameters under laboratory-controlled conditions to determine whether T. remus would be more effective than T. atopovirilia, the best Trichogramma parasitoid in Mexico for S. frugiperda. We found that the former parasitoid had statistically significant longer female and male longevity, as well as a higher proportion of female offspring, and greater numerical values in net reproduction rate, intrinsic rate of increase, and finite rate of increase, but no differences were found in the number of days required for both parasitoids to develop from egg to female or egg to male, as well as in the mean generation time and doubling time. Under the conditions of these trials, T. remus had a 47.02% greater intrinsic rate of increase (r_m) and may thus be a more effective biological control agent for S. frugiperda than T. atopovirilia. However, these biological and population parameter comparisons are the first execution worldwide; further studies are needed to validate these promising T. remus results.