A technique for the bioassay of insecticide deposits on leaf and bark samples in relation to tsetse control operations.

During tsetse control operations it may be necessary to determine the effective toxicity and persistence of insecticide residues on vegetation. A simple method for preparing samples of twig bark for bioassay and an exposure apparatus that has been found very satisfactory for exposing tsetse flies to residues on leaves and bark are described. The apparatus is easily manipulated and involves little handling of the test material.