Mealworms are the larva form of the mealworm beetle, Tenebrio molitor, a species of darkling beetle. Like all holometabolic insects, they go through four life-stages: egg, larva, pupa, and adult. Larvae typically measure about 2.5 cm or more, whereas adults are generally between 1.25 and 1.8 cm in length.
Mealworm beetles (darkling beetles) are prolific breeders. Mating is a three step process: 1) The male gives chase until the female relents. 2) The male then mounts the female and curls his genitals (aedagus) underneath himself and inserts it into her genital tract. 3) The male then injects a packet of semen into the female. Dependent on incubation temperature, just days after mating the female will burrow into soft ground and lays about 500 eggs.
