Tip
Top Bio-Control Technical Bulletin
Whitefly
parasite
Target
Pest:
Greenhouse whitefly (Trialeurodes
vaporariorum); Sweet potato whitefly
(Bemisia tabaci); Silverleaf whitefly
(Bemisia argentifoli); Poinsettia
whitefly; woolly whitefly; Citrus
whitefly; bayberry whitefly. Eretmocerus
has proven to be effective when used
on Greenhouse tomatoes, cucumber,
pepper, eggplant crops, ornamental
crops, interiorscapes and landscapes.
Description:
Eretmocerus is a parasitic wasp. This wasp is a native to the southwestern
U.S. and is adapted to hot, dry climates. Eretmocerus are small wasps
about .6mm (1/50 inch) long. They have a golden yellow thorax and abdomen.
Males have thick antennae. Sex ratio is 50/50. Eretmocerus females lay
their eggs under the nymphs of whiteflies. The eggs then hatch and the
larvae penetrate and consume the whitefly. Approximately 2 weeks after
the eggs are laid, parasitized whiteflies can be identified. The parasitized
whitefly will be a golden color and you should see signs of a developing
wasp inside the pupa. Adults should emerge within 20 days or so, leaving
that distinctive little round emergence hole at one end of the whitefly
pupa. Eretmocerus females will consume immature whitefly as a food source,
puncturing and sucking out their body fluid. Eretmocerus will also feed
on honeydew. Each female can produce 50 - 150 wasps.
Product
information:
Bottles of 3000 emerging Eretmocerus mixed in bran or sawdust are supplied.
The material can be shaken directly onto the leaf surfaces or placed in paper
cups/pouches at the bottom of the plants. Once the material is dispersed
throughout the crop, it should remain there for a few days. The parasitic
wasp will immediately start their work. After about 2 weeks the first parasitized
pupae should be seen in the crop.
Release
Rates:
Release the beneficial insects as soon as possible. If storage is necessary,
store at 8°-10°C (46°-50°F).
Once the first whiteflies are observed, release should be done as soon as
possible.
General release:
5,000 to 20,000 per acre for the first and second week and then 2,000 a week
for 3,4 & 5.
Preventative:
1-2 wasps per 10 sq. ft every 1 - 2 weeks.
Curative:
2-4 wasps per 10-sq. ft. every week for 5-6 weeks.
Monitor the whitefly population with yellow sticky traps.
Lifespan:
Eretmocerus develops from egg to adult in about 3 weeks. Adults live for
about 2 weeks. There are three larval stages, a prepupa and a pupa stage
prior to adult.
Strategic
Considerations:
Eretmocerus are less sensitive to pesticides than Encarsia formosa. Many
pesticides will have a negative effect on the development of Eretmocerus.
Encarsia formosa and Eretmocerus can be used together. Avoid the use of systemic
insecticides or pesticides with long residual action.