Published Paper Details:

Pesticides are documented to have strong impact on the physiological, biological, biochemical and morphological parameters of insects. This study reviews the sub-lethal impact of Cypermethrin (a synthetic pesticide) on various biological parameters of Callosobruchus chinensis. The designed insect was exposed to sub-lethal dose of Cypermethrin. The exposure did not produce immediate mortality of the insect, but had prolonged effects on its biological parameters. The laboratory analysis was carried out with LC10, LC20 and LC30 of the designed pesticide at a room temperature of 25-27 oC and relative humidity of 60-70%. The mean rate of oviposition decreased from control = (96 � 2), LC10 = (92 � 2) to LC20 = (79 � 2) and LC30 = (63 � 3). The percentage of egg development into larvae showed significant decline from control = (94%) to LC10 = (81%), LC20 = (67%) and LC30 = (55%) respectively. In the same way the percentage of adult emergence from the 4th instar larvae of C.chinensis showed significant decline from control (95.00 � 2.00%), LC10 (88.00 � 2.50%), LC20 (55.00 � 2.60%) and LC30 (40.00 � 2.85%). Similarly the mean life span of adult females decreases from control = 12.50 � 0.125 to LC10 = 8.25 � 0.190, LC20 = 6.50 � 0.150 and LC30 = 4.30 � 0.125. Since chemical pest control method is quick, easy and inexpensive, but it is associated with several negative effects on environment therefore in view of the environmental modifications that have significantly impacted our ecosystem, insect population and other beneficial non-target organisms, it is necessary to evaluate the lethal and sub-lethal effects of many pesticides frequently, as this will help to determine the dose response status of insect pests for preference and design of chemicals for control programme.