Department of Agricultural Entomology, University of Agricultural Sciences, Dharwad - 580 005, Karnataka, India.
The acute toxicity trend of pesticides used against Juveniles of earthworm, Polypheritima Elongata indicated that chlorpyrlfos among the insecticides, which was next to the NSKE was found to be the safest insecticide. Endosulfan, cypermethrln, alphamethrin, carbaryl and carbofuran were found to be highly toxic as they registered lowest LC50 values. Mortality of adults was more In lowest concentration of alphamethrin followed by carbaryl, cypermethrin and endosulfan. The pattern of lethality for juveniles was endosulfan = cypermethrln > carbaryl > alphamelhrin > carbofuran > atrazlne > monocrotophos > triazophos > chlorpyrlfos > glyphosate > 2,4-D > gramaxone > indofil (mancozeb) > captan > ridonll (mancozeb + metalaxyl) > NSKE. In general, insecticides were more toxic than herbicides and fungicides to earthworms. In chronic study, also chlorpyrifos was found to be the least toxic recording highest length (at 30, 60 and 90 days after release) and reproduction rate.
