Laboratory studies on the development of resistance to malathion in diamondback moth (Plutella xylostella)

Laboratory studies on the development of resistance in diamondback moth Plutella xylostella (L.) against malathion showed that selection of third instar larvae with malathion by applying a selection pressure of 60–80% kill in every generation resulted into 27.32 times resistance after fourteen generations of selection in comparison to non-selected strain. The rate of development was found to be slower in the initial generations (upto G2) of selection. These finding revealed the ability of P. xylostella to develop resistance to malathion if this insecticides is used continuously for the control of this pest in the field.