Impact of carbaryl insecticides on metamorphosis of Papilio demoleus (l.) larvae in laboratory condition

Abstract

Carbaryl is widely used insecticide. We administrated carbaryl on the 4th instar larvae of Papilio demoleus (L.) and studied developmental toxicity in laboratory condition. Carbaryl dose were 0.25, 0.5, and 1.00 mg/l as foliar spray. Larval malformation rates increased with concentration of carbaryl (R2=0.89 and p>0.05). The skin of larvae became wrinkled and thin with yellow and brown pigmentation. They were slower in movement, loose in muscle contractions, showing hypersalivation and releasing semi-liquid frass. All metamorphosed adult evolved with wrinkled wings and paralytic flight. The result suggested that above 0.5 mg/l carbaryl was responsible for the changes (χ2 = 0.01 - 0.1) of P. demoleus. This concentration can be considered as the safety level for the survival of the butterfly and the existing signature of malformation among both larvae and adult stage can also be used as biomonitoring purpose of the pesticide contaminated environment.