McLaren, G.F. 1989 Control of oystershell scale Quadraspidiotus ostreaeformis (Curtis) on apples in Central Otago.. New Zealand Journal of Crop and Hort. Sci. 17: 221-227.
Notes: Abstract: Current recommendations for control of this species compared; best results optained using oil and chlorpyrifos EC at green tip with or without chlorpyrifos in early January. Keywords: biological control.