Tenebrio obscurus

{{Short description|Species of beetle}}

{{speciesbox

| image = Dunkler Mehlkäfer Tenebrio obscurus 2557.jpg

| taxon = Tenebrio obscurus

| authority = Fabricius, 1792

}}

Tenebrio obscurus, or the dark mealworm beetle, is a species of darkling beetle{{cite journal |last1=Bousquet |first1=Yves |last2=Thomas |first2=Donald B. |last3=Bouchard |first3=Patrice |last4=Smith |first4=Aaron D. |last5=Aalbu |first5=Rolf L. |last6=Johnston |first6=M. Andrew |last7=Jr |first7=Warren E. Steiner |title=Catalogue of Tenebrionidae (Coleoptera) of North America |journal=ZooKeys |date=15 January 2018 |issue=728 |pages=1–455 |doi=10.3897/zookeys.728.20602 |pmid=29416389 |pmc=5799738 |url=https://zookeys.pensoft.net/articles.php?id=20602 |language=en |issn=1313-2970 |doi-access=free }} whose larvae are known as mini mealworms. These insects should not be confused with younger mealworms (Tenebrio molitor){{cite web |last1=Dellinger |first1=Theresa A. |title=Darkling Beetles and Mealworms |url=https://www.pubs.ext.vt.edu/ENTO/ENTO-283/ENTO-283.html |website=Virginia Polytechnic Institute and State University|date=February 17, 2023 |language=en}} or with the confused flour beetle (Tribolium confusum).{{cite web |title=Tribolium 101: Identifying a Flour Beetle |url=https://triboliumbeetles.wordpress.com/2012/11/20/tribolium-101-identifying-a-flour-beetle/ |website=Tribute to the Tribolium |access-date=19 September 2023 |language=en |date=20 November 2012}}

Tenebrio obscurus larvae resemble very small mealworms.

Larvae are cylindrical and initially white, darkening as they mature.

Larvae can reach a length of {{convert|25|to|30|mm}}.

Larvae then pupate, and later emerge as small, black beetles, {{convert|12|to|18|mm}} long. In appearance, adults are similar to the yellow mealworm. They may have a lighter brown color{{cite web |title=Dark mealworm |url=https://www.grainscanada.gc.ca/en/grain-quality/manage/identify-an-insect/secondary-insect-pests/dark-mealworm.html |website=Canadian Grain Commission |publisher=Government of Canada |access-date=19 September 2023 |date=9 April 2018}} or appear dull rather than shiny.{{cite web |title=Darkling Beetle |url=https://www.sites.ext.vt.edu/departments/entomology/factsheets/darkling.html |website=Virginia Cooperative Extension}}

Mini mealworm larvae are used as a feeder insect for birds, reptile and amphibian pets, and zoo animals.{{cite book |last1=Mariod |first1=Abdalbasit Adam |last2=Mirghani |first2=Mohamed Elwathig Saeed |last3=Hussein |first3=Ismail Hassan |title=Unconventional Oilseeds and Oil Sources |date=14 April 2017 |publisher=Academic Press |isbn=978-0-12-813433-7 |url=https://books.google.com/books?id=P43fDQAAQBAJ&pg=PA331 |language=en}}{{cite book |last1=Hall |first1=Heidi |last2=Fitches |first2=Elaine |last3=Smith |first3=Rhonda |title=Insects as Animal Feed: Novel Ingredients for Use in Pet, Aquaculture and Livestock Diets |date=31 August 2021 |publisher=CABI |isbn=978-1-78924-592-9 |url=https://books.google.com/books?id=KFVBEAAAQBAJ&pg=PA11 |language=en}}

Both Tenebrio obscurus and Tenebrio molitor are being studied for their ability to biodegrade waste polystyrene products.

{{cite journal |last1=Peng |first1=BY |last2=Su |first2=Y |last3=Chen |first3=Z |last4=Chen |first4=J |last5=Zhou |first5=X |last6=Benbow |first6=ME |last7=Criddle |first7=CS |last8=Wu |first8=WM |last9=Zhang |first9=Y |title=Biodegradation of Polystyrene by Dark ( Tenebrio obscurus) and Yellow ( Tenebrio molitor) Mealworms (Coleoptera: Tenebrionidae). |journal=Environmental Science & Technology |date=7 May 2019 |volume=53 |issue=9 |pages=5256–5265 |doi=10.1021/acs.est.8b06963 |pmid=30990998|s2cid=119102958 }}{{cite journal |last1=Palmer |first1=Kevin J. |last2=Lauder |first2=Kerri |last3=Christopher |first3=Kyeshaun |last4=Guerra |first4=Fatima |last5=Welch |first5=Rebecca |last6=Bertuccio |first6=Alex J. |title=Biodegradation of Expanded Polystyrene by Larval and Adult Stages of Tenebrio molitor with Varying Substrates and Beddings |journal=Environmental Processes |date=14 January 2022 |volume=9 |issue=1 |pages=3 |doi=10.1007/s40710-021-00556-6 |s2cid=245909637 |url=https://link.springer.com/article/10.1007/s40710-021-00556-6 |language=en |issn=2198-7505|doi-access=free |pmc=8758922 }}