The winter is passed by the insect in almost a mature state; on the advent of spring, development to maturity continues, when, after mating, the females give birth to living young over a period of several weeks. The young reach maturity and commence to reproduce five to six weeks from birth, there being several generations in the course of a season. The average number of young produced by each female has been found to be about 400.
FIG. 7.
(1) Golden Oak Scale; (2) Apple Mussel Scale; (3) Black Scale; (4) Cabbage Tree Scale; (5) San José Scale; (6) Apple Mussel Scale; (7) Oleander Scale; (8) and (9) Rose Scale.
Photographs by W. C. Davies, Cawthron Institute.
Natural enemies in New Zealand are two species of hymenopterous parasites, Aphelinus fuscipennis and A. mytilaspidis, the latter also attacking the apple mussel scale. Ladybird beetles also feed upon the insect.
Control requires close attention, and can be effected by the application of lime-sulphur in the dormant season, when it is essential to apply a strong wash to kill off as many scales as possible before reproduction commences in the spring. At bud movement further applications are necessary to destroy the young insects.