Mealworms, Yellow mealworm beetle
Mealworms are the larval form of the yellow 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 centimetres (0.98 in) or more, whereas adults are generally 1.25 to 1.8 centimetres (0.49 to 0.71 in) in length.
The mealworm beetle breeds prolifically. Males insert sperm packets with their aedeagus. Within a few days the female burrows into soft ground and lays eggs. Over her adult lifespan of about 6-12 months, a female will, on average, lay about 500 eggs.
After 4 to 19 days the eggs hatch.
During the larval stage, the mealworms feed on vegetation and dead insects and molt between each larval stage, or instar (9 to 20 instars). After the final molt, they pupate. The new pupa is whitish and turns brown over time. After 3 to 30 days, depending on environmental conditions such as temperature, it emerges as an adult beetle.
Tenebrio molitor is often used for biological research. Its relatively large size, ease of rearing and handling, and status as a non-model organism make it useful in proof of concept studies in the fields of basic biology, biochemistry, evolution, immunology and physiology.
