Journal of Economic Entomology (2004) 97, 1239-1244

Katharina B. Rothwangl, Raymond A. Cloyd and Robert N. Wiedenmann (2004)
Effects of insect growth regulators on citrus mealybug parasitoid Leptomastix dactylopii (Hymenoptera: Encyrtidae)
Journal of Economic Entomology 97 (4), 1239-1244
Abstract: In this study, we measured the effects of three commonly used insecticides classified as insect growth regulators, on the encyrtid parasitoid Leptomastix dactylopii (Howard) when parasitizing citrus mealybug, Planococcus citri (Risso). Kinoprene, pyriproxyfen, and azadirachtin were evaluated in both petri dish and a cage experiment at label-recommended rates to measure their effects on the mortality, parasitization rate, and sex ratio of L. dactylopii. Insecticides were applied to petri dishes and plants either immediately before, 24 h before, or 48 h before release of the parasitoid. Kinoprene applied 24 h before parasitoid release caused 100% mortality of L. dactylopii in petri dishes within 48 h. Mortality rates for L. dactylopii exposed to azadirachtin and pyriproxyfen did not exceed 5% regardless of release time. There were no release time x insecticide interactions on L. dactylopii parasitization rate. The insecticide alone, however, did significantly affect parasitization rates of L. dactylopii on P. citri; the kinoprene treatment significantly reduced L. dactylopii parasitization rates compared with azadirachtin and pyriproxyfen. In a cage experiment with coleus, Solenostemon scutellaroides (L.) Codd, applications of both pyriproxyfen and kinoprene resulted in fewer P. citri parasitized by L. dactylopii than azadirachtin or the control. The sex ratio was equivalent in the petri dish experiment, whereas in the cage experiment the sex ratio was biased toward males, particularly for the kinoprene treatment. Based on the results from this study, we suggest that kinoprene is not compatible with releases of L. dactylopii to control citrus mealybugs.
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Research topic(s) for pests/diseases/weeds:
health/environmental effects of pesticides
control - general
Research topic(s) for beneficials or antagonists:
resistance to pesticides

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Planococcus citri
Leptomastix dactylopii (parasitoid)	Planococcus citri