Effect of sweetpotato genotype, storage time and production site on feeding and oviposition behavior of the sweetpotato weevil, Cylas formicarius (Coleoptera : Apoinidae)

The effect of sweetpotato genotype, storage time and production site on Cyl as formicarius (Fab.) feeding and oviposition was investigated. Sweetpotato genotype had a significant effect on feeding and oviposition rates in both no-choice and choice arenas. Beauregard and Centennial were uniformly susc eptible across all age groups. W-250 had the least number of feeding punctu res and eggs at 7 and 25 days after harvest. At 85 days after harvest, W-24 4 had the least number of feeding punctures and eggs, while W-250 was not s ignificantly different from Beauregard and Centennial. Roots of the same ge notype grown in different locations differed in the number of feeding punct ures and eggs. These results suggest that antixenosis is responsible for at least part of the sweetpotato weevil resistance. Storage time and producti on sites appeared to affect the expression of the resistance, but the outco mes depended on the genotypes.