Pests: find out more WHITEFLY

Whitefly

The Pest

The glasshouse whitefly (Trialeurodes vaporariorum) is a familiar pest, attacking a wide range of greenhouse crops.  It feeds on the plant sap reducing plant vigour and can multiply rapidly.  It can also transmit viruses and the honeydew produced can encourage the growth of "sooty moulds" which reduce the plants photosynthetic ability and may affect the quality of fruit and flowers.

The notifiable tobacco whitefly (Bemisia tabaci) is similar to the glasshouse whitefly, causing similar problems and is an important vector for damaging viruses such as the Tomato Yellow Leaf Curl Virus.

Increasing resistance of whitefly to chemical pesticides is making the use of biological control more important in the management of this pest.

Whitefly Adults

Whitefly adults on leaf

Adults are small white flying insects. They feed on the growing shoots of plants and lay their eggs on the young leaves (eggs are often laid in circles). 

The eggs hatch into larvae, which are mobile initially, but once they have found a suitable feeding site they insert their mouthparts and remain there, feeding on the plant sap.  The larvae are small, oval, translucent scales found on the undersides of young leaves near the growing points.  There are four larval stages before the whitefly becomes a pupa. These are also attached to the underside of the leaf on which the original eggs were laid.

Development time is dependent upon the leaf temperature and food quality. The adult whitefly emerges from the pupae on the lower leaves but then fly to the younger leaves to lay their eggs.

Whitefly can overwinter on plants in the glasshouse and the egg stage is able to withstand quite low temperatures.