MEALWORMS or DARKLING GROUND BEETLES: YELLOW MEALWORM, Tenebrio obscurus; DARK MEALWORM, T. molitor, Tenebrionidae
ADULT: Reddish-brown to black, oval, flattened 1/2 to 1 in. long beetles. The tarsi on the front and middle legs are five segmented, while the tarsi on the hind legs are four segmented. Base of mandible without a hardened, raized area (including teeth or ridges).
EGG: Oval, whitish eggs are deposited singly or in clusters in roasting stage corn ears. Larvae emerge in 4 to 8 d.
LARVA: They are whitish, becoming yellow to light brown, narrow, hard-bodied, worm-like larvae with three pairs of true legs. The head and thorax are harder and darker than the abdomen. They resemble wireworm larvae and reach 1 to 1 1/2 in. long.
PUPA: White (becoming brown) pupa formed in the soil without a protective cell.
DAMAGE: Larvae feed on seed and sileage corn drying in fields where they can severely damage ears. Corn can be infested in the field with damage continuing as corn goes into storage.
CONTROL: Cultural controls include harvesting corn and disking fields as soon as ear moisture content will allow. There are no pesticides specifically labeled for mealworm conrol in Florida corn.