Eretmocerus eremicus is a small parasitic wasp the also host feeds on greenhouse and silverleaf whitefly nymphs. E. eremicus lays an egg inside the nymph stage of greenhouse whitefly. One wasp forms inside of the parasitized immature stage of the whitefly, killing the whitefly. Parasitized whitefly pupae turn tan colored and adult Eretmocerus wasps emerge. E. eremicus are smaller than encarsia and therefore are able to parasitize the smaller silverleaf whitefly species. Also, E. eremicus are also more tolerant of higher temperature and host feeds more than Encarsia.
Eretmocerus are purchased as loose parasitized pupae that are mixed with a carrier. The eretmocerus emerge as adults and search out whiteflies in the greenhouse to parasitize.
To learn more about biocontrol for whitefly see: Greenhouse Pests and their Natural Enemies and Biological Control: A Grower's Guide to Using Biological Control for Silverleaf Whitefly on Poinsettia under the Insects and Mites Section of UMass Extension Greenhouse Crops and Floriculture fact sheets.