Perturbation of the soil microarthropod community with the pesticides benomyl and isofenphos. I, Population changes

The microarthropods (mites and Collembola) at 3 localities were perturbed with a single application of isofenphos, normal dose, and benomyl, 5 times normal dose and sampled for 6 years. Isofenphos strongly reduced all species, the least sensitive were euedaphic and epedaphic Collembola and Acari with high reproductive potential. Reductions have been observed during the whole period. Benomyl had indirect effects which resulted in stimulations that lasted for 3-4 years and slight reductions particularly within the first 2 years. Largest pesticide effects were observed in sandy soils. Interactions with microorganisms, Lumbricidae, predators and competitors and discussed as explanations for the changes