Widespread distribution. Maize, sorghum, barley, millet, and many grasses. Rarely important in Pacific islands.
Damage: (i) feeds on sap causing distortions and wilts; (ii) produces honeydew leading to sooty moulds on leaves, and prevents release of pollen (maize); (iii) spreads viruses - but not in Pacific islands.
Females produce living young without mating; nymphs light green, becoming bluish or olive green adults, up to 2 mm long, rectangular; base of 'conicles' (upright tubes) purple.
Winged forms when populations large. Spread also in wind currents.
Natural enemies: ladybird beetles and parasitoid wasps (Aphelinus, Lysiphlebus).
Cultural control: plant far from old infested crops, hot water to kill ants; weed; collect and destroy debris after harvest; tolerant varieties (maize, sorghum).
Chemical control: PDPs (chilli, derris, neem, pyrethrum); soap, white or horticultural oils; synthetic pyrethroids will kill predators and parasitoids (but useful against ants).