Whitefly: potato and cabbage pest in Indonesia and Western Australia

Page last updated: Friday, 3 July 2020 - 12:25pm

Please note: This content may be out of date and is currently under review.

Whitefly is a relatively minor pest of potato and cabbage crops in both Indonesia and Western Australia.

The Department of Agriculture and Food, Western Australia has worked with the Indonesian potato industry to increase the productivity of Indonesian crops planted with WA seed potatoes.

Improved productivity requires accurate identification of pests in potatoes and also as in the cabbage rotation crop.

As well as helping Indonesian farmers this information will assist Western Australian seed potato exporters understand the challenges their Indonesian customers face.

Identification

The Indonesian name for whitefly is "kutu putih" and it is in the insect family Aleyrodidae.

Whiteflies reduce potato and cabbage plant vigour by sucking sap from leaves. There are several species, but all adults are small at about 1.5mm long with white wings.

Whitefly adults and eggs on the underside of young leaves – white eggs are newly laid and darker eggs are close to hatching
Whitefly adults and eggs on the underside of young leaves

Adults lay eggs on the underside of young leaves. The eggs are pale when first laid and turn black just before hatching into nymphs.

Whitefly nymphs settle and feed on the underside of leaves
Whitefly nymph
Young whitefly nymphs and an aphid (the larger insect). Whitefly and wingless aphids are similar but whitefly do not have cornicles on each side of the end of the aphid's body. Also aphids move around but whitefly feed in the one position
Young whitefly nymphs and an aphid (the larger insect)

Whitefly immature stages are called nymphs which occur on the undersides of leaves. They are grey to white, circular and soft-bodied, similar to aphid nymphs. But unlike aphids, whitefly nymphs lack cornicles on the abdomen and do not move once they start feeding.

Sooty mould is a fungus that develops on honeydew excretions on leaves from feeding by nymphs and adults of whiteflies
Sooty mould caused by whitefly feeding

Symptoms of whitefly damage include wilting leaves and the presence of black sooty mould. These symptoms are rarely seen because only large numbers of whitefly will cause such effects. The sooty mould is a fungus that grows on the sugary honeydew that nymphs and adult whitefly excrete when they are feeding.

Cocoons of whitefly - cream ones are healthy, unparasitised; yellow ones are parasitised. Cocoons from which whitefly adults have emerged are grey, empty with a split and cacoons from which a wasp emerged have a circular hole chewed in them
Cocoons of whitefly - healthy and parasitised

When mature, whitefly nymphs form into white oval cocoons on the underside of leaves. Cocoons are cream when not parasitised, yellow when parasitised.

Cocoons from which whitefly adults emerge are grey shells with a split line, and cocoons from which wasp parasites have emerged have a circular hole cut in them.

A video on whitefly stages is available.

Contact information

Stewart Learmonth
+61 (0)8 9777 0167

Whitefly: potato and cabbage pest in Indonesia and Western Australia

Author

Stewart Learmonth