Insecticidal Activity of Cleisthopholis patens (Benth) Engl and Diels (Annonaceae) Against the Stored Product Moth, Ephestia cautella (Walker) [Lepidoptera:Pyralidae], in Stored Cocoa [Theobroma cacao (L.)]Beans.

The toxicity of powdered leaf, stem bark and root bark of “apako”, Cleisthopholis patens (Benth) Engl and Diels (Annonacea), to Ephestia cautella (Walker) was evaluated in the laboratory at 28±2°C and 75±5% RH. Four rates of each powder. 0.5, 1.0,2.0, and 3.0 g/20 g of cocoa [Theobroma cacao (L.)] beans. were tested in completely randomized design. The treatments and an untreated control were replicated three times. In another test, treated and untreated cocoa beans were infested with 30 one-day old E. cautella eggs and the numbers of hatched eggs (at day 3 post-infestation) and emerged adults (at day 40 postinfestation) were converted to percentages. Toxicity to adults generally increased with the rate of product application and duration post-treatment. At 24 h post-treatment, only the root bark caused mortality (22.8-45.3%). Mortality increased considerably thereafter reaching the peak (100%) at 72 h for 3.0 g root bark/20 g cocoa bean, and at 96 h for 2.0 g and 3.0 g stem bark. With the leaf powder. the highest mortality was 78.9% for 3.0 g/20 g cocoa bean. All parts of C. patens at 0.5-3.0 g/20 g cocoa beans completely inhibited egg hatch whereas on the untreated control the percentage of hatched eggs ranged between 73.4 and 96.7% and percentage adult emergence ranged between 60.0 and 90.0% .