Pests
 
Greenhouse whitefly Pests main menu
 

The greenhouse whitefly (Trialeurodes vaporariorum) is a typical greenhouse pest that affects many crops.

 

  Biology
 

Adult greenhouse whiteflies measure about 2 mm and are covered with a white waxy powder. Their wings are positioned horizontally and overlap slightly. The female greenhouse whitefly deposits its oval-shaped eggs of 0,2 mm on the underside of leaves at the top of the plant. After 2 - 3 days they turn black.


The larva that hatches is first mobile during a few hours to search for a suitable place on the leaf to settle. Later on, and in the subsequent larval stages and pupal stage, it does not move anymore. The four larval stages look very similar, but differ clearly in size.
The white, transparent pupa is round with an upright edge. The pupa is covered with hairs.
An adult greenhouse whitefly emerges from the pupa through a T-shaped exit hole.


On tomato, development from egg to adult takes 20 days at 27°C or 38 days at 17°C, but on other host plants this can be quite different.
Also fertility depends on temperature and host plant. A female lays about 100 eggs on tomato, 200 eggs on cucumber and 300 eggs on eggplants.


 

  Damage
  As well larvae as adults suck plant juices. Secretion of honeydew fouls the leaves and the fruits, which become not marketable. Often moulds grow on the honeydew, which stunts photosynthesis and respiration of the plant.
  Beneficials
 
Encarsia formosa Eretmocerus eremicus
With the parasitic wasp Encarsia formosa the greenhouse grower disposes of a practical and economical beneficial insect to control whitefly populations.
Eretmocerus eremicus can develop in any larval stage of the whitefly, and therefore it is an excellent biological control agent for whitefly.
Macrolophus caliginosus Paecilomyces fumosoroseus
Since a few years tomato and eggplant growers get support from the predatory bug Macrolophus caliginosus to control whiteflies.
PreFeRal WG is a new biological insecticide that provides excellent control of the greenhouse whitefly in protected cultures of tomato and cucumber.
   
 

 

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