Agrochemicals play a significant role in increasing the productivity of crops but it has a very serious effect on the fauna and flora of the soil ecosystem. Soil collembolans play a decisive role in boosing soil fertility. Unsystematic use of agrochemicals for agricultural purposes resulted in harmful effects on the biology and species diversity of soil microarthropods. Collembola is a group that functions as a bio-indicator of the soil condition. Laboratory toxicity tests were carried out, to evaluate the effects of agrochemicals- Acrinathrin (pyrethroid pesticide), Mancozeb (Fungicide) and Altrazine (Herbicide) on fecundity and moulting intervals of an edaphic collembolan Bilobella braunerae (Collembola) grown in the sub lethal concentration of agrochemicals. The LC 50 values of agrochemicals for Bilobella braunerae were calculated. The safe and sub-lethal concentrations of agrochemicals were very low, indicating the high vulnerability of these collembolans to agrochemicals. The safe level concentration of Acrinathrin (pyrethroid pesticide), Mancozeb (Fungicide) and Altrazine (Herbicide) were 1.25ppm, 0.1850ppm, 0.0355ppm respectively. The collembola feeding on leaves of jackfruit containing sub lethal concentration agrochemicals exhibited trends of increased days in moulting and decreased fecundity rates. The moulting intervals of B.braunerae showed variation between the agrochemical treated and control group. The moulting intervals were prolonged after treatment. The inhibition of growth, moulting and fecundity was seen above the sub-lethal concentration. Both moulting and fecundity rates were significantly affected by the agrochemicals when presented as food to the collembola. The untreated control sets recorded growth, moulting fecundity for B. braunerae, but chronic toxicity of the insecticides on adults confined to the treated food resulted into very low fecundity and prolonged moulting intervals. Even short duration exposure to agrochemicals treated food for 24 or 72 hours, was found to delay the egg-laying and decrease the fecundity of the species. It is concluded that population responses and reproductive sensitivity in non-target soil microarthropods are potential eco- toxicological parameters for detecting agrochemical pollution in soil and for ecological health assessment. The present studies revealed that agrochemicals has a profound effect in reducing the fecundity of B. braunerae, but the toxic effect of Altrazine (Herbicide) is high when compared to Acrinathrin, Mancozeb.