Comparative activity of three repellents against bedbugs Cimex hemipterus (Fabr.)

Comparative activity of three repellents viz., diethyl-m-toluamide (DEET), diethyl phenyl-acetamide (DEPA) and dimethylphthalate (DMP) against bedbugs Cimex hemipterus (Fabr) was studied by applying repellent solution on the shaven skin of rabbits. DEET (Tech. grade) 20mgai/cm2 exhibited 93 and 83 per cent repellency after 2 and 8 h respectively, while DEPA (Tech. grade) at this concentration exhibited 90 and 71 per cent repellency. DEET and DEPA at 75 per cent concentration (15mgai/cm2) showed 85 and 78 per cent repellency up to 2 h and 52 and 42 per cent repellency 6 h after treatment respectively. The repellent activity was also found to be concentration and time of treatment dependent in respect of DEET and DEPA. DMP (Tech. grade) did not show any appreciable repellent activity at any concentration tested. Further, the blood intake by C. hemipterus following treatment with various concentrations of repellents was found to decrease with increase in the concentration of repellents.