• Widespread distribution. Southeast Asia, Africa, South America, Oceania. On coffee, mainly. A major pest.
• Eggs laid under the scale; nymphs ('crawlers') disperse, moult and adults feed on shoots, expelling excess sap as honeydew. Feeding weakens trees as do sooty moulds growing on the honeydew excreta. Ants prevent control by wasps and ladybird beetles.
• Natural enemies: parasitoid wasps exist, but are only effective in the absence of ants.
• Cultural control: scale-free nurseries; maintain shade; use 'Tanglefoot' to control ants; grow pumpkins in coffee to attract ladybird beetles.
• Chemical control: soap, white or horticultural oils; or synthetic pyrethroids for ant control.

Coffee green scale

Coccus celatus. Note there is another species of scale present on coffee, known as soft green scale (Coccus viride). In Papua New Guinea, both occur on the same coffee trees, but separation of the species requires expert examination of slide-mounted specimens. Coccus celatus is the more important.