Includes bibliographical references (pages 14-15).

Abstract. Materials and Methods. Residue Concentration and Change. Acknowledgments. References. Study plots were treated with specific quantities of active ingredient per hectare with either DDT, dieldrin, or heptachlor. Earthworms and soils were sampled from each treated plot at specific time intervals (up to 2 years after treatment) and analyzed by gas chromatography for specific pesticide residues. Individual and total metabolites in soils and earthworms tended to increase linearly with increasing levels of application. In soils, losses of specified biocides varied by species over time ranging from no significant loss to a decrease in heptachlor during the two years following application. In earthworms, maximum residues usually occurred 2-4 months after application, then declined. During the decline, residue levels were cyclic: levels elevated from late spring to early fall and depressed from late fall to early spring. High levels (usually May) and lows (usually January) coincided with seasonal high and low activity of eathworms.