THE STRUCTURE OF FEEDING-BEHAVIOR IN THE COLORADO POTATO BEETLE, LEPTINOTARSA-DECEMLINEATA (COLEOPTERA, CHRYSOMELIDAE)

Feeding behavior, in an ad libitum situation on potato plants in the l aboratory, was continuously observed for approximately 7 h/day on 2 su ccessive days for 18 adult female Leptinotarsa decemlineata. Additiona l behaviors were also recorded including resting, walking, biting, loc al movements, grooming, defecating, and regurgitating. These data were used to calculate a time budget for the various behaviors. The feedin g data were analyzed to describe the structure of feeding for young ad ult females on their normal host plant. The criterion for a meal (mini mum intermeal interval) was determined to be 286 s. This criterion was used to distinguish between intra- and intermeal interruptions in fee ding for all subsequent analyses. Meals taken from leaves that were yo ung, medium aged, or old did not differ, but on average beetles took 6 0% of their meals from young leaves. Meal size and meal duration were equally good predictors of when a meal would end. Feeding from stems w as a prominent feature for most beetles. The stem meals had much longe r durations than leaf meals, but stem feeding did not affect subsequen t leaf feeding. The structure of feeding by these beetles is compared with that found in other insects, especially Locusta migratoria.