Ecotoxicological effects of agrochemicals on the biological parameters of Earias vitella Fab.

Larvae of Earias vitella (Fab.) were collected of okra crop and kept in petridishes solution of five agrochemicals was prepared in separate buckets viz. salicylic acid at 2000 ppm, Pix at 100 ppm, v - cyhalothrin at 12.50 ppm Match at 250 ppm and Runner at 120 ppm and compared with untreated control. Okra fruits dipped in separate solution for 10 seconds and kept on ground for dryup, then treated fed larvae reared in petridishes till pupation, artificial diet was provided. The pupae was kept in the glass jars (9 cm dia) till emergence of adult. After emergence the adults were paired (male and female) and reared in glass chimney for egg laying. Moths were fed on Glucose solution (10% up) impregnated into cotton wool placed in small plastic bottle lid. A small twig of okra plant dipped in water contained in small glass vial was placed inside the chimney for the egg laying, the solution was changed at alternative days. The egg was laid on the ten der leaves and on impregnated cotton wool. Twigs and cotton wool was changed with fresh one daily. Eggs laid were counted and kept in petridishes for hatching. Fresh food was provided to the newly emerged larvae daily till the pupation during the two consecutive generations. It was observed during 1st generation no differences were observed in the incubation period of eggs between the treated larvae and untreated control. However, larval period and adult longevity periods increased in the treated larvae, while pupation period decreased. Match was found more toxic and caused mortality of larvae during the larval period, followed by salicylic acid with increased larval period (17.33 plus minus 1.52 days) and Runner (16.66 plus minus 3.51 days) respectively. Salicylic acid treated also reduced pupation period (6.4 plus minus 1.67 days) when compared other agrochemical and untreated control. While Runner reduced adult longevity (12.75 plus minus 3.87 days) as pupal weight, fecund ity, and fertility compared other treated larvae reduced in all treatments as higher pupal weight (0.0472 plus minus 0.0159, gm) the reduction in pupal weight was more or less similar but low as compared to control. The fecundity period was greatly reduced in v-cyhalothrin treated larvae (75.00 plus minus 5.00 days) while Runner reduced fertility (32.50 plus minus 1.19), (40.63%). Mortality of Earias vitella was greater incase of Match (100%) and v-cyhalothrin (70%) and Runner (55%) respectively. In the 2nd generation incubation period and larval period chanced while pupal period and adult longevity decreased in all agrochemical treatments. Incubation period was more in pix (4.5 plus minus 0.69 days), larval period in case of salicylic acid (15.50 days) pupal greatly incase of runner (10.25 plus minus 1.510 days and 12.33 plus minus 3.440 days) respectively. Pupal weight was more or less similar in all treatments, but was low as compared to untreated larvae. Fecundity and fer tility was reduced greatly incase of v-cyhalothrin (59.00 plus minus 2.480 and 25.00 plus minus 1.070) respectively. However, match and v-cyhalothrin displayed greater mortality (100 and 67%). It may be concluded that among the five agrochemical evaluated, Match and v-cyhalothrin were more toxic and have long lasting effect on biological parameters of Earias vitella (Fab.) in the laboratory conditions.