Bioassay of Various Formulations of Insecticides on the Egg and Larval Stages of the Coffee Berry Borer Hypothenemus Hampei Ferrari (Scolytidae: Coleoptera)

Abstract

Twenty-three insecticide formulations were bioassayed for toxicity against the eggs and larvae of H. hampei in maturing and ripe berries of C. arabica L. Var. typica. The infested berries were dipped in different concentrations of individual formulations, dissected 24 hr later for recording larval mortality and transferring the eggs to wet filter papers where larval hatching was recorded for the next 4 days. The order of toxicity and LC₅₀ (% a.i. x 10³) values for the eggs in maturing and ripe (figures in parenthesis) berries were: thiodan EC 35, 5.1 (6.2) > perfekthion, 5.9 (8.1) > decis, 7.2 (9.4) > carbicron, 7.3 (9.8) > actellic, 10.6(12.9) > thiodan EC 3, 14.7 (17.4); > folimat > aldicarb > dursban > tiovel > supona > dimilin > methomyl > kelthane > phosdrin > sevin > methoxychlor > dieldrin > azordrin > fenitrothion > bimarit > chlorpyrifos > gardona, 39.7-1043.7 (44.3-2642.2). The order of toxicity remained almost the same for the larvae, the LC₅₀ values being 2.1-12.7 (2.9-21.8) for the top six and 14.8-1920.4 (47.1 2738.6) for the remaining 17 formulations. Generally, the formulations were 1.1-2.7-fold more toxic to larvae than to eggs infesting the maturing berries but 0.47-3.57 more toxic to eggs than larvae in the ripe berries.