The term “darkling beetle” refers to several genera within the insect family Tenebrionidae which includes about 20,000 species. These genera are also referred to as “pinacate beetles.”
These insects are found worldwide, but are most commonly encountered in the deserts of the western United States, with as many as 450 species in California alone.
Known commonly as “stinkbugs,” some beetles in this genus emit noxious odors in the chemical class quinones from the ends of their abdomens or behind their heads as a defensive mechanism.
Many types of this beetle do “headstands” to ward off predators – whether they have the ability to produce bad odors or not.
Typically they can be found under stones, around decaying matter, or walking right out in the open. I mainly find them under plywood boards that I lift while looking for snakes.
This is one of the largest species of Darkling Beetles I have encountered. At home I keep two other species and raise them for their larval state: the mealworm, which is used to feed pet reptiles, birds and amphibians.