Although information on insecticide toxicity on pests abounds, this is limited on non-target organisms like ants in cocoa production systems. This study determined the toxicity of insecticides (containing acetamiprid 40 g L−1 EW, acetamiprid 64 g L−1 + emamectin benzoate 48 g L−1 EC, acetamiprid 20 g L−1 + lambda-cyhalothrin 15 g L−1 SC, emamectin benzoate 5% WDG and pyrethrins 50 g L−1 EW) used against cocoa pests on non-target predatory ants (Crematogaster africana, Oecophylla longinoda and Pheidole megacephala) under laboratory (using filter-paper method) and field conditions to identify less harmful products for use in the cropping system. Ant knockdown and mortality varied significantly among insecticides at their recommended rates, with emamectin benzoate being the least toxic and acetamiprid + lambda-cyhalothrin the most toxic. LC95s varied significantly, with emamectin benzoate having the highest predator safety index, while pyrethrins had the lowest. Generally, selectivity towards O. longinoda was higher than that towards the other ants. In the field, emamectin benzoate had the least acute adverse effect on ant abundance. Ant population generally rebounded to pre-treatment levels at 1 month after the last insecticide application. The study indicates differential toxicity and identifies ant-compatible insecticide options contingent on the autochthonous ant composition.
Avicor et al. (Mon,) studied this question.