Consumption of Eggplant Foliage by Colorado Potato Beetle (Coleoptera: Chrysomelidae)

Feeding of second- to fourth-instar Colorado potato beetle, Leptinotarsa decemlineata Say, on eggplant was monitored at constant temperatures of 20, 26, 29, 32 and 35° C, and at 16, 20, 27, 29, and 33° C for adults to determine the effects of temperature on consumption. For comparison, consumption by each stage relative to fourth instars was standardized to feeding equivalants. A significant non-linear relationship was found between temperature and consumption for each life stage tested. Placement of each life stage on an equivalent feeding basis showed second instars consume on average 21.5% as much foliage as fourth instars, third instars 51.2% the amount of fourth instars, and adults 39.0% the level of fourth instars. These feeding equivalents can be used to develop field sampling plans and toxicant bioassays.