MORTALITY AND PREDATION EFFICIENCY OF COLEOMEGILLA MACULATA LENGI TIMB (COL, COCCINELLIDAE) FOLLOWING APPLICATION OF NEEM EXTRACTS (AZADIRACHTA-INDICA A-JUSS, MELIACEAE)

The toxicity of two neem (Azadirachta indica) extracts and of the chemical insecticide malathion was evaluated on adults of the predacious coccinellid C. maculata. Bioassays were carried out with both neem formulations at 1, 5, 10, 20 and 50% concentration. The azadirachtin quantities contained in neem oil (v/v) and neem seed kernels (w/v) were 13.7 ppm AZA and 91.0 ppm AZA respectively. Malathion was tested at held rate (2.85 g (AI)/L). The mortality rate was evaluated in the laboratory after topical applications on the ventral side of the coccinellids. Adult mortality rate after 72 h was 100% following malathion treatments. Only one dose of neem oil (10%) resulted in significantly greater mortality than in the control group. No toxicity was observed after the treatments with the aqueous suspension of ground neem seeds. Predation efficiency of C. maculata was also evaluated after topical application of these three insecticides at sublethal doses. Fifteen min after treatments, adult coccinellids were presented 30 aphids for 24 h. The aqueous suspension of ground neem seeds caused a 50% reduction in the number of aphids consumed.