The leaf area of a solanaceous weed, Solanum carolinense, consumed by larvae and adults of a leaf scraping coccinellid beetle, Epilachna vigintioctopunctata, was measured using a computer-assisted image processing system (IPS). The accuracy of this IFS was examined by measuring areas of 25 mm x 25 mm, 50 mm x 50 mm, and 100 mm x 100 mm reference plates. The relative measurement error of the IFS was <1% for all plates. It was also demonstrated that the IFS could be effectively used to measure the leaf area consumed by a leaf-scraper insect by comparing the IFS measurements with those of an area meter. A feeding experiment of E. vigintioctopunctata on S. carolinense was carried out for 38 days at 25 degrees C under 16L-8D, and the leaf area consumed was measured by the IFS. An average beetle consumed 1,429.5+/-131.6 (S.D.) mm(2) of leaves to complete its larval development and consumed 2,510.9+/-306.2 mm(2) of leaves during the first 10 days of its adult stage.