Integrated Management of the Onion Maggot (Diptera: Anthomyiidae)

Abstract

In the absence of crop rotation, onion maggot, Delia antiqua (Meigen), control was inadequate (<10% plant loss) in field trials within a commercial onion production area when susceptible and potentially resistant onion genotypes were treated with chlorpyrifos at planting. However, when treatments were applied to the same entries in an area that had been rotated completely out of onion production the previous year, exceptional onion maggot damage reduction was noted (<2% plant losses). In the nonrotated area, one genotype (PI 432715) had reduced onion maggot damage compared with that of susceptible onion cultivars when treated with half rates of chlorpyrifos. Rotation of complete production areas can provide effective onion maggot control. When rotation is not possible, integration of plant resistance and judicious application of insecticides may be appropriate.