Family Tenebrionidae (Darkling Beetles)

The number of species in the Tenebrionidae is estimated at more than 20,000 and the family is cosmopolitan in distribution. The name means “lover of darkness”. In general, numerous Tenebrionidae species do inhabit dark places, however, there are many species in genera such as Stenocara and Onymacris, which are active by day and inactive at night.

Tenebrionids may be identified by a combination of features, including:

Their 11-segmented antennae that may be filiform, moniliform or weakly clubbed.
First abdominal sternite is entire and not divided by the hind coxae.
Eyes notched by a frontal ridge.
The tarsi have four segments in the hind pair and five in the fore and mid legs (5-5-4), tarsal claws are simple.

Tenebrionids occur in deserts and forests as plant scavengers, most species are generalist omnivores as larvae and adults, feeding on decaying leaves, rotting wood, fresh plant matter, dead insects, and fungi. Several genera are specialized fungivores which feed on polypores. Many of the larger species are flightless, and those that can fly rarely do so.

The larvae are commonly known to us as mealworms and are usually fossorial, heavily sclerotized and nocturnal, and are an important food resource to certain invertebrates and small mammals. The adults of many species however have chemical defenses against predation. Adults of most species, except grain pests, have slow metabolisms, and live long lives compared to other insects, ranging from approximately six months to two years.