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.
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 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.
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.
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.