Van Wyk, H.P.D. 1994 . The Effect of Selected Insect Growth Regulators on the Development of Red Scale Aonidiella aurantii (Maskell) (Hemiptera: Diaspididae). Ph.D. Thesis, University of Pretoria (South Africa)

Notes: [Ph.D. Thesis.] The effect of three insect growth regulators namely, buprofezin (chitin synthesis inhibitor), pyriproxyfen (juvenile hormone mimic) and CGA 59205 (juvenile hormone mimic) on the developmental stages of red scale, Aonidiella aurantii (Maskell), were determined. All experiments, as well as the mass rearing of red scale, were done on butternuts, Cucurbita moschata. All three insect growth regulators had a strong inhibiting effect on the males of red scale, except treatment of the pupae. This strong inhibiting effect is mainly because of the complete metamorphosis they have to undergo. If they survived the treated stage, mortality was mainly noticed during the pupal stage or emergence of the males. The females of red scale on the other hand are much less sensitive to insect growth regulators, mainly because of their incomplete metamorphosis. If they had survived the treated stage as well as the following moult, most of them survived to the reproductive stage. The most sensitive sessile stages to insect growth regulator treatment, in the case of the females, are the first instar and the first moult.