Worldwide distribution. On fruit trees, and many vegetables. An important pest.
Damage: (i) feeds on sap causing distortions and wilts; (ii) produces honeydew leading to sooty moulds; and (iii) spreads more than 100 viruses.
Adults, 2 mm long, greenish-yellow, sometimes with brown tinge, winged or wingless, giving birth without fertilisation (in the tropics). No males.
Spread by winged forms, and also in wind and storms, and trade in plants.
Natural enemies: predators and wasp parasitoids (Aphidius and Aphelinus).
Cultural control: weed; certified seed (beans); avoid planting down-wind from infested crops; remove volunteers; grow flowering plants to attract wasps; inspect crops often - remove infested plants or leaves (or spray); use plastic mulches, row covers; control ants with boiling water; collect and destroy debris after harvest.
Chemical control: PDPs (chilli, derris, neem, pyrethrum); soap solution, white or horticultural oils. Note, synthetic pyrethroids will kill predators and parasitoids (but useful against ants).