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 degrees C, and at 16, 20, 27, 29, and 33 degrees 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.