By Robin Street
Geographic Range
This species probably evolved in Eurasia, but has been introduced around the world by human activity.
Biogeographic Regions:
nearctic 
(introduced ); palearctic (native ); oriental (introduced ); ethiopian (introduced ); neotropical (introduced ); australian (introduced ); oceanic islands (introduced ).
Other Geographic Terms:
cosmopolitan .
Habitat
If not living in graineries, closets, and cupboards, mealworm beetles live in rotting wood, termite and ant nests, and even desert areas.
Terrestrial Biomes:
tundra ; taiga ; desert or dune ; savanna or grassland ; chaparral ; forest ; rainforest ; scrub forest ; mountains .
Physical Description
Mealworm beetles are 13-16 mm long. They are elongated, ovoid in shape and slightly flat, reddish black to black in coloration; head is wide and rounded. Their elytra have many fine lengthwise crenelations. The larvae, which are yellow to pale reddish brown in color, grow up to 32 mm in length.
Some key physical features:
ectothermic ; bilateral symmetry .
Reproduction
Mealworm beetles deposit white bean-shaped eggs on dry foods consumed by people. Larvae live through the winter, pupae in the spring, and emerge a adult beetles during the summer. There is one generation per year.
Behavior
Adults and larvae are nocturnal; they attack rugs, clothing, skins, dried plants, and taxidermy mounts.
Food Habits
This mealworm beetle eats stored grain, bran, cerials, packaged foods, and other stored foods consumed by people.
Economic Importance for Humans: Negative
Mealworm adults and larvae are damaging to graineries and the stored foods of humans.
Economic Importance for Humans: Positive
Mealworms are bred as food for aquarium fish, reptiles, and amphibians.
Conservation Status
No special conserns regarding the conservation of this species.
Other Comments
None.
For More Information
Find Tenebrio molitor information at
Contributors
Robin Street (author), University of Michigan.
