Effects of biopesticide Neem EC on the Large White Butterfly, Pieris brassicae L. (Lepidoptera, Pieridae)
Institute of Agricultural and Environmental Sciences, Estonian University of Life Sciences,Kreutzwaldi St. 64, 51014 Tartu, Estonia; e-mail: email@example.com
The effects of Neem EC (M/S RYM Exports – The Indian Neem Tree Company, 1% azadirachtin) were assessed on the Large White Butterfly, Pieris brassicae – a major pest of cruciferous plants. Duration of the larval stage, mortality of larvae and prepupae, and weight of pupae were studied. The time needed for completion of the larval stages by individuals fed on treated cabbage increased significantly, compared with the control: 16–37 days in the test variant, versus 11–18 days in the control. Neem EC also induced high mortality, caused by lethal failures of larval-larval and larval-pupal ecdysis, which were typical for insecticides possessing morphogenetic activity commonly referred to as IGR-activity. The mortality of larvae and prepupae in the test variant was significantly higher than in the control. Considerably fewer pupae were gained in the test variant than in the control variant. The pupae of larvae that had been feeding on the control were significantly heavier than those of the larvae feeding on the treated plants. The experiment revealed that Neem EC had both toxic and antifeedant/deterrent effects but also acted as a growth regulator for P. brassicae larvae.