• Worldwide distribution. Small (1-2mm) greenfly on backs of young leaves or tips of shoots. In tropics, females only: they give birth to living young. Populations increase rapidly. A major pest.
• Damage results from sucking sap, spreading viruses, moulds that grow on honeydew excreta, blackening leaves.
• Natural enemies: syrphids (hoverfly larvae), lacewing larvae, ladybird beetle adults and larvae, and parasitoid wasps. Note, ants take honeydew from the aphids, and in so doing protect them from natural enemies.
• Cultural control: check plants in nursery; plant away from crops with aphids; inspect crops regularly: remove infested shoots/leaves; weed, use reflective mulches.
• Chemical control: soap, white or horticultural oils; PDPs: derris, pyrethrum, or chilli; synthetic pyrethroids, but these will kill predators and parasitoids. Removing ants will allow natural enemies to control aphid populations. Use hot water or pyrethroids.

Melon or cotton aphid. There are many aphids attacking a wide range of crops; Aphis gossypii, described here, is common in Pacific island countries.

Aphis gossypii