Effect of intercropping on oviposition and emigration behavior of the leekmoth (Lepidoptera : Acrolepiidae) and the diamondback moth (Lepidoptera : Plutellidae)

We compared the effect of intercropping on oviposition and emigration behav ior of two related specialist moth species. The effect of height of the int ercrop species (red clover) on oviposition was studied in field cages, usin g the leek moth, a specialist on Allium species, and the diamondback moth, a specialist an Brassica species. The moths were also evaluated in an open field experiment. Emigration of both moths was studied in the laboratory an d in the field in cages with host plants, red clover (nonhost), host plant and red clover, and bare soil. The possible influence of noncontact stimuli was also studied in the laboratory. The leek moth laid the same amount of eggs in monoculture as in intercroppings with high and low clover. white ca bbage intercropped with high clover received fewer eggs of the diamondback moth compared with a cabbage monoculture. Intercropping with low clover did not reduce the amount of eggs laid. Intercropping did not appear. to affec t the emigration of either the leek moth or the diamondback moth, Leek moth s were less likely to emigrate than diamondback moths during the first 4 h of the study. We conclude that diamondback moth may be more likely to be co ntrolled by intercropping than leek moths.