The oyster-shell scale, Quadraspidiotus ostreaeformis (Curtis), in the Christchurch district of New Zealand

Abstract

The life history of the oyster-shell scale, Quadraspidiotus ostreaeformis (Curtis), a pest of fruit trees in many parts of the world, is described for New Zealand. One generation only is present each season. First and second ins tar scales occur on fruit and may cause pitting and red marks. The scale is recorded from 8 apple varieties, 2 pear varieties, 2 plum varieties, flowering apple, and flowering cherry. Parasites and predators of the scale are recorded from unsprayed orchards, the most important being the Hymenopterous endoparasite Aspidiotiphagus citrinus (Craw.) and the mite Neophyllobius.