A QUANTITATIVE STUDY OF FOOD CONSUMPTION, ASSIMILATION, AND GROWTH IN LEPTINOTARSA DECEMLINEATA (COLEOPTERA: CHRYSOMELIDAE) ON TWO HOST PLANTS

Abstract

Larvae of Leptinotarsa decemlineata (Say) reared on tomato fed longer, consumed more foliage, and had a lower survival rate than when reared on potato, its principal host. On both plants, a direct linear relationship was obtained between food consumption and larval growth. Potato was the more efficient of the two plants in terms of food conversion to body matter. This was reflected by increased weight gain of the larvae and greater pupal size. Adults from larvae reared on tomato were smaller and less fecund than those from larvae reared on potato. Half of them rejected tomato as food. However, egg-laying increased when they were transferred to potato after 50 days. The present investigation indicates that L. decemlineata can survive and attain maturity on tomato in the absence of its principal host plant. However, when potato is once again available, it is able to increase growth, accelerate development, and achieve a greater reproductive potential.