First massive occurrence of greenhouse whitefly parasitoid, Encarsia formosa Gahan (Hymenoptera: Aphelinidae) on greenhouse whitefly, Trialeurodes vaporariorum [Westwood] (Homoptera: Aleyrodidae) in Slovenia

Abstract

In 2008, massive population of parasitoid Encarsia formosa was found for the first time in the greenhouses on the Laboratory Field of Biotechnical Faculty in Ljubljana (Slovenia). This species is known for a long time as effective natural enemy of the greenhouse whitefly, Trialeurodes vaporariorum, and other whiteflies in different parts of the world. 1306 wasps from genus Encarsia were found in nymphs of greenhouse whitefly. The most numerous was E. formosa (934 individuals), following by 367 individuals of E. tricolor, 4 males of E. inaron and a male of E. longicornis. Greenhouse whitefly parasitoid was determined on 14 host plants in the greenhouse and E. tricolor on 11 host plants in the greenhouse and on one host plant in the field. E. inaron and E. longicornis appeared only on one host plant in a greenhouse. For the time being the use of wasp E. formosa is not yet permitted in controlling greenhouse whitefly in Slovenia, but there is possibility to include it in the programs of biological control of pests on ornamentals and vegetable plants in the greenhouses. Consequently, the use of chemical insecticides will be reduced.

Keywords

• greenhouse whitefly parasitoid
• Encarsia formosa
• greenhouse whitefly
• Trialeurodes vaporariorum
• biological control
• natural enemies