Abstract
The effects of nine insecticides on the numbers and biomass of earthworms were studied three weeks after plots in pasture were treated. Dursban, BAYER 37289 and DDT had very little effect, but Dasanit, carbofuran and Stauffer N-2596 drastically lessened numbers and biomass of earthworms sampled with formalin solution. BUX, endrin and carbaryl did not lessen numbers by more than 60% or the biomass by more than 68.3%.