Reproductive effects of the insecticide acephate on a springtail and an enchytraeid in a subtropical soil.

The widespread use of acephate, a common insecticide, raises concerns about its potential impacts on nontarget soil organisms. This study investigated the chronic effects of acephate on the reproduction of two key soil fauna species, the springtail Folsomia candida and the enchytraeid Enchytraeus crypticus. We exposed these organisms to acephate in both natural Cambisol soil and tropical artificial soil (TAS) to assess potential impacts under different environmental conditions. Our results revealed significant reductions in reproduction for both species, with effects ranging from 38% to 49% (based on control and lowest observed effect concentration values). Furthermore, the observed effects were dependent on both the organism and the soil type. Springtails exhibited greater sensitivity in TAS than in Cambisol (0.09 and 15.0 mg a.i. kg-1 soil dry wt, respectively), whereas enchytraeids were more sensitive in Cambisol than in TAS (1 and 100 mg a.i. kg-1 soil dry wt, respectively). These findings highlight the importance of considering species-specific responses and soil properties when evaluating the ecological risks of pesticides on soil fauna communities.