White Fly Trialeurodes vaporariorum, Bemisia tabaci
Whiteflies are not true flies, but belong to the order Hemiptera (true bugs). Together with aphids and scale insects, they belong to the division Sternorrhyncha. The whiteflies form the family Aleyrodidae. The most common species are the greenhouse whitefly, Trialeurodes vaporariorum, and the tobacco whitefly, Bemisia tabaci. Both are widespread, and are broadly comparable in outline. [Read More]
Whiteflies are not true flies, but belong to the order Hemiptera (true bugs). Together with aphids and scale insects, they belong to the division Sternorrhyncha. The whiteflies form the family Aleyrodidae. The most common species are the greenhouse whitefly, Trialeurodes vaporariorum, and the tobacco whitefly, Bemisia tabaci. Both are widespread, and are broadly comparable in outline.
The larvae of whitefly need a lot of protein for growth, and thus consume a large quantity of plant sap. This contains a high proportion of sugar, and the excess is excreted as honeydew, with larger larvae expelling large quantities. The damage that whiteflies cause to a crop is the result of sucking out the sap from the plant leaves and secreting honeydew. This can have the following consequences:
- If the population is very large, feeding on plant sap can affect the physiology of the plant, as a result of which growth is retarded. In full sunlight, leaves can wilt and fall. Such leaf damage can in turn influence the development of fruit and lead to a reduction in yield.
- The honeydew deposited on fruit makes it sticky. Dirt adheres to the fruit, and the growth of sooty moulds (Cladosporium spp.) is encouraged, making it unsuitable for sale. In serious cases the fruit will rot. Sooty moulds also develop on the leaves, reducing photosynthesis and transpiration.
- Viruses can be transmitted.
- The consumption of plant sap and secreting of honeydew by whiteflies reduce the aesthetic value of crops. This is particularly important in ornamentals.
FAQs About White Fly
What causes white fly infestation?
Whitefly is a piercing/sucking insect that is common in all horticultural/agricultural areas and is known to vector certain viruses amongst plant families. Whitefly can originate from outside of the growing facility on landscaping or agricultural plants where they may overwinter protected from the elements. They may also be brought in on propagated plants from another facility. There is increasing evidence that over-fertilization of plants (specifically Nitrogen) can benefit Whitefly populations by providing more nutrients to the pest.
How long do white flies last?
The typical agricultural/horticultural Whitefly species will quickly grow to serious populations quickly due to their short lifespan. Every female Whitefly can lay between 100-200 eggs in her lifetime, depending on host plant and climate. With a three-week lifecycle, the population exponentially grows if no control actions are taken. An adult Whitefly can live for two months or more under common horticultural conditions.
How do I prevent whitefly infestation?
Since Whitefly populations grow so quickly, prevention is key to their control. Inspect incoming plant material and treat with natural enemies and preventative sprays. Hang yellow monitoring cards above the canopy of the crop and take counts of trapped Whitefly weekly to measure populations quantitatively. Introduce specialized natural enemies like Amblyseius swirskii, Encarsia formosa, or Eretmocerus eremicus preventatively before pest pressure is detected. Hang larger sticky cards or tape to trap adults before they can lay eggs in the crop.
How do you identify a white fly?
There are two main species of Whitefly that commonly affect agricultural/horticultural crops: Greenhouse Whitefly (Trialeurodes vaporariorum) and Tobacco Whitefly (Bemesia tabaci). While these pests may look similar to the untrained eye, they can be distinguished by several characteristics: Greenhouse Whitefly wings lay flat against the body, they normally lay eggs at the top of the plant, and their larval/pupal stages typically produce small hair-like filaments while Tobacco Whitefly wings form a "tent" shape on the body, will lay eggs throughout the structure of the plant, and produce slightly yellow larvae/pupae with no hair-like filaments.
Questions About White Fly?
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