Ecology, Environment and Conservation Paper

SURVIVAL, BODY MASS AND TRANSPIRATION OF THE PESTICIDE - TREATED EARTHW RM APORRECTODEA CALIGINOSA (SAVIGNY 1826) (OLIGOCHAETA LUMBRICIDAE)

Suaad Ali Bennour, G. Achuthan Nair* and Abdalla I. Mohammed

Abstract

Experiments were conducted for 28 days to study the effects of 90, 30, 10 and 3.3 mg/kg dry soil of pomex (carbamate), formothion (organophosphorus) and fenvalerate (pyrethroid) insecticides, glycphosate (herbicide) and ridomil (fungicide), on the survival, body mass and transpiration of Aporrectodea caliginosa, a common earthworm found in the farmlands of Benghazi, Libya. Pomex and fenvaleratc were found to be highly toxic to A.caliginosa killing all the worms within 9 to 15 days of exposure at 90 mg/kg soil. The survival rates of the worms treated with formothion, glyphosate and ridomil ranged from 0 to 70%. A significant difference (F = 5.03; P <0.05) was observed in the changes in the body mass of the control and the pesticide-treated worms. The lower concentrations (30, 10, 3.3 mg/kg soil) of most of the pesticides tried triggered an increase in the body mass during the initial exposure period with a decline thereafter. Significant differences (F = 314; P <0.05) were discernible in the transpiration rates ofA.caliginosa treated with different concentrations of the pesticides.