SUMMARYTen arable fields and two apple orchards were chosen from a total of thirty‐five sites visited to represent typical soils, crop rotations and insecticide applications in the Huntingdon area of East Anglia. Pitfall traps were used to collect insects and other invertebrates during fortnightly periods from early April until harvesting and in one orchard until the following February. Estimates of active biomass were obtained for several groups of invertebrates and differences between the sites are discussed. Samples of beetles, earthworms and slugs were collected during June and were sent with soil samples to the Government Chemist for analysis of organochlorine residues. The soil residues are compared with those in respective invertebrate samples and with stated application rates. It is concluded that soil invertebrates could form a regular source of pesticide residues for ground‐feeding birds but that the levels are generally too low to cause acute poison