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.

mealworm larva
Larvae are elongate and cylindrical (worm-like), hard-bodied and yellow to golden brown in color. (Yellow mealworm larvae)

mealworm larva
Larvae and adults are usually found in moist, dark, undisturbed places. (Dark mealworm larva)

mealworm adult
Adults are nocturnal, black, hardshelled beetles about 1 inch long. (Yellow mealworm adult)

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Identification and Control Information

[Photos: Clemson University - USDA Cooperative Extension Slide Series,]