Blister Beetle

alarmed. Larvae occur in rotten wood and plant pith; some are leaf and stem miners, and a few are predaceous.

Superfamily Tenebrionoidea

Tarsi 5-5-4. Front coxal cavities closed behind (except in Melan-

dryidae). Mostly moderate in size.

DARKLING BEETLES Family Tenebrionidae

Identification: Antennae usually 11-segmented, threadlike, beadlike, or slightly clubbed. Eyes nearly always notched. Tarsal claws simple. Generally dull black or brown, sometimes with red. 2-35 mm. A varied group usually recognizable by 5-5-4 tarsi, form of eyes, and antennae.

This is a large group whose members are common in a variety of habitats — under bark, in rotten wood, under logs, in fungi, on the ground in desert areas, and in termite and ant nests. Some are pests of stored products. Both adults and larvae are scavengers, feeding on decaying vegetation, fungi, seeds, and other types of organic materials; a few attack living plants.

Darkling beetles are variable in body form and often resemble beetles in other families. Members of the genus Diaperis, which inhabit fungi, are similar in appearance and coloration to ladybird beetles. Many species rather closely resemble ground beetles, though they are usually not as shiny. Some fungus-inhabiting tenebrionids have the dorsal surface hard and warty. A species of this type is the Forked Fungus Beetle, Bolitotherus cornutus (Panzer), which is 10-12 mm. and common in woody bracket fungi; the pronotum of the male bears 2 hornlike protuberances.

A few are destructive to stored grain and flour. Members of the genus Tenebrio (black or dark brown and 13-17 mm.) are pests of stored grain; their larvae are called mealworms. Beetles in the genus Tribolium are brown and about 5 mm.; they are pests of flour and other stored products and are known as flour beetles.

Members of the genus Eleodes run about with the abdomen raised at an angle of about 45 degrees. They emit a foul-smelling black fluid when disturbed. About 100 species of Eleodes occur in the western states.

Darkling beetles are widely distributed but are most abundant in the western states; of the approximately 1400 N. American species, only about 150 occur in the East.


Identification: Shape and antennae distinctive: elongate, narrow, FW widest apically, pronotum narrower than FW, head about as wide as pronotum; antennae threadlike, last segment elongate. Dark-colored, often slightly metallic. 6-15 mm.

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