Greenhouse whitefly, this snow-white aphid lays its eggs on the underside of leaves.
Also known as:
glasshouse whitefly
Do not confuse with:
Silverleaf whitefly (Bemisia tabaci)
Greenhouse whitefly (Trialeurodes vaporariorum) This snow-white aphid 1 to 2 mm long lays its eggs on the underside of leaves. Greenhouse whitefly is related to the scale insects. The larvae therefore resemble scale insects, but are translucent. The larvae live off plant sap. They secrete honeydew that molds (sooty mold).
The greenhouse whitefly can also transmit several plant viruses.
Where to find
- Vegetable garden
- Cucumber family:
- Potato
- Tomatoes
- Houseplants
- Poinsettia (houseplant, greenhouse)
- African hemp
Control
Difficult to control. Remove infested plants. Spray with pyrethrum. The parasitic wasp (Encarsia formosa) can also be used in greenhouse cultivation. This biological pest control is commercially available.
Prevention
Greenhouse whiteflies do not like drafts and a dry environment; some draft in the greenhouse on sunny days helps prevent whiteflies.
Some scents keep greenhouse whiteflies away, such as marigolds, basil and apple-of-Peru (Nicandra physalodes); plant these among plants in the vegetable garden and in the greenhouse.
The parasitic wasp is a natural enemy and is used in horticulture in greenhouses to to control the grenhouse whitefly.
Provide the windows with insect screens at greenhouses to keep the flies out.
Remove weeds (because often host plants of the greenhouse whitefly) can maintain the infestation.
