Evidence for behavioural resistance by the diamondback moth, Plutella xylostella (L.)

The diamondback moth (DBM), Plutella xylostella (L.) (Lep., Plutellidae), is an important pest of brassicaceous crops worldwide. It has developed resistance to almost every synthetic insecticide applied in the field and consequently is often difficult to control in crucifer‐growing areas. DBM oviposition behaviour was investigated in greenhouse and growth chamber conditions with seven cruciferous and one non‐cruciferous plant varieties. In free choice tests, females deposited more eggs on the stem near the soil‐stem interface than on leaves. Our findings suggest that DBM is capable of developing behavioural resistance through oviposition site selection to avoid lethal doses of foliar‐applied insecticides in the field.