White wax scale: a pest of citrus

Abstract

In the highlands if a citrus tree is examined a number of small white spots of wax can often be found. The leaves, stems and fruit
of these trees are usually covered with a black ’deposit. The white spots are insects called white wax scales, Gascardia destructor. These
scales feed by sucking the sap from the plants through special mouth parts which are pushed into the plant stem. The black
’deposit’ is a fungus called sooty mould. This lives on a sweet sticky substance called honey dew which is produced by the white wax scales.