The Insecticidal Effects of Organic Compounds: 1 Toxicity of sulfur and nitrogen compounds to fleshfly larvae1

Abstract

The studies which are proceeding in many laboratories on the toxic effects of organic compounds toward insects have already provided an immense amount of data, but have led as yet to only a few generalizations regarding structure and toxicity which may be used for selection of materials for practical use. Among the numerous difficulties particular importance attaches to the multitude of compounds already known or possible to make, the lack of agreement on methods of testing and the use of insects of unknown physiological or genetic condition. Comparatively few species of insects are suitable for laboratory rearing over long periods and many economic species undergo a more or less compulsory dormant period during the winter, thereby introducing the probability of seasonal variations in susceptibility. In consequence of this situation an inordinate proportion of the toxicity studies has been made with the silkworm and with grain insects. An extreme method of avoiding the biological difficulties inherent with insects is the use of the goldfish, Carassius auratus, for evaluation of possible organic insecticides (Gersdorff, 1936; Gersdorff & Claborn, 1938).