Mealworms: Dark Mealworm—Tenebrio obscurus and Yellow Mealworm—Tenebrio molitor
Mealworms are common, widespread insects that occasionally infest stored products. Usually found in undisturbed areas such as dark corners, under sacks, and in bins where feed is stored. In homes they are sometimes found in cornmeal, flour, cake mixes, and cereals.
Larvae are elongate and cylindrical (worm-like), hard-bodied and yellow to golden brown in color. (Yellow mealworm larvae)
Larvae and adults are usually found in moist, dark, undisturbed places. (Dark mealworm larva)
Adults are nocturnal, black, hardshelled beetles about 1 inch long. (Yellow mealworm adult)
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Identification and Control Information
- Fact Sheet: Mealworms—University of Maine Cooperative Extension
- Dark and Yellow Mealworms—Penn State Extension
[Photos: Clemson University - USDA Cooperative Extension Slide Series, Bugwood.org]