In order to evaluate the potential use of Trichogramma spp. in the biological control of Spodoptera frugiperda, experiments were carried out in an effort to study the biology and parasitism capacity of Trichogramma atopovirilia and T. pretiosum on the natural host S. frugiperda. T. pretiosum was the most abundant (93,73%) among the collected species in corn fields followed by T. atopovirilia (2.07%). Both T. atopovirilia and T. pretiosum had a good biological performance and were adapted to S. frugiperda eggs even after being reared on A. kuehniella for several generations, although T. atopovirilia was more aggressive towards the pest. T. atopovirilia and T. pretiosum females had the same size when reared on A. kuehniella eggs, however, when reared on S. frugiperda the T. pretiosum females were bigger than the T. atopovirilia ones. The presence of scales on eggs laid by S. frugiperda decreased the number of parasitized eggs and affected the behavior of both species, since the time spent on each stage of the parasitism behavior increased, the female moving time at egg laying after the end of an oviposition increased, and the time in which the female remained parasitizing on the eggs decreased. Under greenhouse, an increased number of egg layers on the eggs laid by S. frugiperda was observed, with a decreased parasitism capacity of T. atopovirilia. Thus, one infers that the parasitism by T. atopovirilia and
T. pretiosum is affected by the physical barriers of S. frugiperda eggs, which may lead to a decreased performance of the parasitoid in the field.
Species 1: Hymenoptera Trichogrammatidae Trichogramma atopovirilia
Species 2: Hymenoptera Trichogrammatidae Trichogramma pretiosum
Species 3: Lepidoptera Noctuidae Spodoptera frugiperda (fall armyworm)
Keywords: biological control, egg parasitoid
The ESA 2001 Annual Meeting - 2001: An Entomological Odyssey of ESA