Worldwide distribution. In tropics and sub-tropics. Common on about 80 plant families, particularly fruit and forest trees, and herbaceous ornamentals, but also ferns, orchids and palms. Citrus and mango are the main hosts. An important pest.
Eggs laid under females. “Crawlers” disperse, settle - often along midribs - moult and feed on sap, with excess expelled as honeydew. Damage by feeding and by sooty moulds growing on honeydew excreta and blackening leaves.
Natural enemies: parasitoid wasps, but ants interfere with control by wasps and ladybeetles.
Spread by crawlers on wind, and in the nursery trade.
Cultural control: check nursery plants are free of scales; prune infested branches; destroy ants (hot water).
Chemical control: soap, white or horticultural oils; or synthetic pyrethroids for ant control.