Improved methods of testing and release of Aphidoletes aphidimyza (Diptera: Cecidomyiidae) for aphid control in glasshouses

Abstract

The gallmidge Aphidoletes aphidimyza is used commercially to control aphids infesting greenhouse crops such as sweet pepper and tomato. In this study we investigated several different ways of improving its use as a biocontrol agent. In the laboratory there was a very strong relation between the availability of spider's webs and successful mating. When mated in cages containing spider's webs a greater proportion of the females were mated and the females laid more eggs compared to the females in cages without spider's webs. As adults emerging from cocoons can crawl up through 15 cm of vermiculite it is possible to transport and release them from bottles, which can be placed open in a greenhouse instead of having to spread the material around the plants. Dispersal of adults from the bottles was measured by placing sentinel plants around a single release point. Eggs of the gallmidge were found on plants at distances up to 45 m from the release point. Intraguild predation of the eggs of the gallmidge by the mites Amblyseius degenerans and Amblyseius cucumeris was also assessed.