Eretmocerus warrae
Overview
Eretmocerus warrae is a small parasitic wasp used to control Greenhouse Whitefly (Trialeurodes vaporariorum) in a range of vegetables and ornamentals.
Eretmocerus are about 1mm long, a little larger than the whitefly parasitoid Encarsia, and completely yellow. They can be used in all crops where Greenhouse Whitefly is present and tend to be better suited to plants with more hairs on the lower leaf surface than Encarsia.
Target crops include greenhouse vegetables (tomato, cucumber, eggplant), ornamentals (gerbera, chrysanthemum, rose), strawberries and herbs. In summer and in warmer climates, Eretmocerus are also useful in outdoor nursery stock and gardens. They are strong fliers so are generally released into hotspots to build up and spread themselves from these positions.
Tolerant of a wide range of temperatures and relative humidity, Eretmocerus are particularly useful in very hot conditions which hinders Encarsia development.
Eretmocerus are also more tolerant to some pesticides than many other parasites and also predates non-parasitised stages. It does not attack Silverleaf Whitefly (Bemisia tabaci).
Pests Eretmocerus warrae can help you control
You can use Eretmocerus warrae to control Greenhouse Whitefly but not Silverleaf Whitefly.
How Eretmocerus warrae controls pests among crops
The female Eretmocerus prefers 2nd stage whitefly nymphs for egg laying. On hatching, after about 4 days, the wasp larva bores into the whitefly and waits until the whitefly pupates. It then releases digestive enzymes to dissolve the whitefly innards which the wasp larvae feeds on.
Unlike Encarsia which turns the whitefly body black, it is a little harder to monitor how well Eretmocerus is establishing because it turns the whitefly body a light yellow colour.
Non-parasitised whitefly nymphs are an important source of nutrients for the adult females and host feeding contributes to whitefly control.
We recommend you use Eretmocerus and Encarsia formosa together. In tomato and eggplants, use Eretmocerus with Nesidiocoris tenuis to achieve the best whitefly control.
Certain pesticides and fungicides affect Eretmocerus so contact your local Biological Services Consultant for specific advice.
How you can order Eretmocerus warrae
You can order Eretmocerus warrae from Biological Services as 1000 pupae/vial.
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