Pests & Problems

The following is a list of common pests found in crops both outdoors and in greenhouses.  

Unless properly controlled or eradicated, these pests can have severe effects on plant health,  reducing quality and quantity of yields.

Two Spotted Mite 

(Tetranychus urticae)

 

Description:  Approximately 1mm in length, yellowish-green in colour with dark spots on either side of the body.

 

Damage:  Fine speckling on upper surface of leaf.  

Heavily infested leaves may become bronze coloured, shrivelled and can cover leaves or flowers in webbing.

(Bean Spider Mite similar to Two Spotted Mite)

Aphids

 

Description:  Approximately 7 mm in length, light to dark green in colour and dark lines on back.

 

Damage:  Aphids feed on sap from plants causing deformation of new growth and flowers.  

Aphids are also carriers of crop diseases and viruses including mosaics.

Greenhouse Whitely 

(Trialeurodes vaporariorum)

 

Description:  Dark greyish-purple eggs are laid on underside of leaf.  

Adults approximately 2mm in length, resemble white moth features.

 

Damage:  Whiteflies produce honeydew which results in mould growth.  

Plants become yellow, wilt, shed leaves and growth rate reduces.

Caterpillars

 

Description:  Different varieties can alter in colour size and appearance.  

Immatures caterpillars can grow up to 30mm in length.

 

Damage:  Larvae and immatures feed on leaves, fruit and flowers causing extensive damage to crops.  

Damage is evident by irregular flower petals and holes in fruit or leaves.

Powdery Mildew

 

Damage:  White powdery appearance on infected host's tissue.  

Starts in small circular white patches,  extensive damage results in yellow shrivelled leaves and death.

Western Flower Thrips 

(Frankliniella occidentalis)

 

Description:  Females approximately 1-2mm in lengh.  

Yellowish orange colour with darker abdomen.  Males slightly smaller and paler yellow.

 

Damage:  Thrips feed on plant cells causing discolouration, distortion and bronzing of leaves and flowers. 

(similar to Tomato Thrips)

Fungus Gnats

 

Description:  Found on soil or leaves.  Small, dark thin flies with long legs and antennae.

 

Damage:  Adults are carriers of foliar diseases such as Botrytis.  

Larvae feed on roots and stems and can sometimes cause collapsing of tissue in root systems.  

Can be a devastating pest if not controlled.