Biological control using Trichogramma pretiosum Riley (Hymenoptera: Trichogrammatidae), an egg parasitoid wasp, was tested in Uruguay to reduce populations of lepidopteran pests on soybeans. It was observed that the commercial parasitoid dispensers, which were made of cardboard, were vulnerable to small predators that succeeded in entering and emptying the containers of all the eggs parasitized...

Intraguild predation (IGP) is common in food web when two natural enemies share the same resources and prey. It may affect the success or failure of a biological control attempt. The role of intraguild predation by Geocoris ochropterus Fieber (Heteroptera: Geocoridae) on Trichogramma chilonis Ishii (Hymenoptera: Trichogrammatidae) developed on eggs of Helicoverpa armigera (Hubner) (Lepidoptera:...