Tenebrio molitor

Life-forms

Superregnum: Eukaryota
Cladus: Unikonta
Cladus: Opisthokonta
Cladus: Holozoa
Regnum: Animalia
Subregnum: Eumetazoa
Cladus: Bilateria
Cladus: Nephrozoa
Cladus: Protostomia
Cladus: Ecdysozoa
Cladus: Panarthropoda
Phylum: Arthropoda
Subphylum: Hexapoda
Classis: Insecta
Cladus: Dicondylia
Subclassis: Pterygota
Cladus: Metapterygota
Infraclassis: Neoptera
Cladus: Eumetabola
Cladus: Endopterygota
Superordo: Coleopterida
Ordo: Coleoptera
Subordo: Polyphaga
Infraordo: Cucujiformia
Superfamilia: Tenebrionoidea

Familia: Tenebrionidae
Subfamilia: Tenebrioninae
Tribus: Tenebrionini
Genus: Tenebrio
Species: Tenebrio molitor
Name

Tenebrio molitor (Linnaeus, 1758)
References
Primary references

Linnaeus, C. 1758. Systema Naturae per regna tria naturæ, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis, Tomus I. Editio decima, reformata. Holmiæ: impensis direct. Laurentii Salvii. i–ii, 1–824 pp DOI: 10.5962/bhl.title.542: 417. Reference page.

Links

Tenebrio molitor Taxon details on Fauna Europaea
Tenebrio molitor Linnaeus, 1758
ZooBank: 19EE3BC1-AD92-4A15-82F1-EB3DBE81DFE6

Vernacular names
čeština: Potemník moučný
Deutsch: Mehlkäfer
English: Mealworm beetle
suomi: Jauhopukki
français: Ténébrion meunier
magyar: Közönséges lisztbogár
հայերեն: Ալերորդ
한국어: 갈색거저리
Nederlands: Meeltor
polski: Mącznik młynarek
русский: Мучной хрущак большой / Мучной жук
slovenčina: múčiar obyčajný
ไทย: หนอนนก, กระดิ่งเงินกระดิ่งทอง
Türkçe: Un kurdu

Mealworms are the larval 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 centimetres (0.98 in) or more, whereas adults are generally between 1.25 to 1.8 centimetres (0.49 to 0.71 in) in length.

Reproduction
Tenebrio molitor larvae eating an apple slice

The mealworm beetle breeds prolifically. Mating is a three-step process: the male chasing the female, mounting her, inserting his aedeagus, and injecting a sperm packet. Within a few days the female burrows into soft ground and lays eggs. Over a lifespan, a female will, on average, lay about 500 eggs.

After four to 19 days the eggs hatch. Many predators target the eggs, including reptiles.

During the larval stage, the mealworm feeds on vegetation and dead insects and molts between each larval stage, or instar (9 to 20 instars). After the final molt it becomes a pupa. The new pupa is whitish, and it turns brown over time. After 3 to 30 days, depending on environmental conditions such as temperature, it emerges as an adult beetle.
Sex pheromones

A sex pheromone released by male mealworms has been identified.[1] Inbreeding reduces the attractiveness of sexual pheromone signaling by male mealworms.[2] Females are more attracted to the odors produced by outbred males than the odors produced by inbred males. The reduction of male signaling capability may be due to increased expression of homozygous deleterious recessive alleles caused by inbreeding.[3]
Relationship with humans

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.
As pests

Mealworms have generally been considered pests, because they feed on stored grains. Mealworms probably originated in the Mediterranean region, but are now present in many areas of the world as a result of human trade and colonization. The oldest archaeological records of mealworms can be traced to Bronze Age Turkey. Records from the British Isles and northern Europe are from a later date, and mealworms are conspicuously absent from archaeological finds from ancient Egypt.[4]
As feed and pet food
Main articles: Insects as feed and Insect based pet food

Mealworms are typically used as a pet food for captive reptiles, fish, and birds. They are also provided to wild birds in bird feeders, particularly during the nesting season. Mealworms are useful for their high protein content. They are also used as fishing bait.

They are commercially available in bulk and are typically available in containers with bran or oatmeal for food. Commercial growers incorporate a juvenile hormone into the feeding process to keep the mealworm in the larval stage and achieve an abnormal length of 2 cm or greater.[5]
As food
Main articles: Insects as food and Entomophagy in humans
Mealworms in a bowl

Mealworms are edible for humans, and processed into several insect food items available in food retail such as insect burgers.[6]

Mealworms have historically been consumed in many Asian countries, particularly in Southeast Asia. There, they are commonly found in food markets and sold as street food alongside other edible insects. Baked or fried mealworms have been marketed as a healthy snack food in recent history, though the consumption of mealworms goes back centuries.

In May 2017, mealworms were approved as food in Switzerland.[7] In June 2021, dried mealworms were authorized as novel food in the European Union,[8] after the European Food Safety Authority assessed the larvae as safe for human consumption.[9][10]

Mealworm larvae contain significant nutrient content. For every 100 grams of raw mealworm larvae, 206 calories and anywhere from 14 to 25 grams of protein are contained.[11] Mealworm larvae contain levels of potassium, copper, sodium, selenium, iron and zinc that rival that of beef. Mealworms contain essential linoleic acids as well. They also have greater vitamin content by weight compared to beef, B12 not included.[11][12]

Mealworms may be easily reared on fresh oats, wheat bran or grain, with sliced potato, carrots, or apple as a moisture source. The small amount of space required to raise mealworms has made them relevant for scalable industrialized mass production.[13]
In waste disposal

In 2015, it was discovered that mealworms can degrade polystyrene into usable organic matter at a rate of about 34–39 milligrams per day. Additionally, no difference was found between mealworms fed only styrofoam and mealworms fed conventional foods, during the one-month duration of the experiment.[14] Microorganisms inside the mealworm's gut are responsible for degrading the polystyrene, with mealworms given the antibiotic gentamicin showing no signs of degradation.[15] Isolated colonies of the mealworm's gut microbes, however, have proven less efficient at degradation than the bacteria within the gut.[15]
See also

Zond 5, a 1968 space mission on which mealworms were among the first terrestrial organisms to travel to and circle the Moon[16]
Organisms breaking down plastic

References

Bryning GP, Chambers J, Wakefield ME (2005). "Identification of a sex pheromone from male yellow mealworm beetles, Tenebrio molitor". Journal of Chemical Ecology. 31 (11): 2721–30. doi:10.1007/s10886-005-7622-x. PMID 16273437. S2CID 28709218.
Pölkki M, Krams I, Kangassalo K, Rantala MJ (2012). "Inbreeding affects sexual signalling in males but not females of Tenebrio molitor". Biology Letters. 8 (3): 423–5. doi:10.1098/rsbl.2011.1135. PMC 3367757. PMID 22237501.
Bernstein H, Hopf FA, Michod RE (1987). "The molecular basis of the evolution of sex". Molecular Genetics of Development. Advances in Genetics. Vol. 24. pp. 323–70. doi:10.1016/S0065-2660(08)60012-7. ISBN 978-0-12-017624-3. PMID 3324702.
Panagiotakopulu E (2001). "New records for ancient pests: archaeoentomology in Egypt". Journal of Archaeological Science. 28 (11): 1235–1246. doi:10.1006/jasc.2001.0697.
Finke, M.; Winn, D. (2004). "Insects and related arthropods: A nutritional primer for rehabilitators". Journal of Wildlife Rehabilitation. 27: 14–17.
Ledsom, Alex (13 January 2021). "Insect Market To Explode: EU Gives Green Light To Eating Mealworm". Forbes.
"Insects as food" (in German). Bundesamt für Lebensmittelsicherheit und Veterinärwesen. 2017-04-28.
"Commission Implementing Regulation (EU) 2021/882 of 1 June 2021 authorising the placing on the market of dried Tenebrio molitor larva as a novel food under Regulation (EU) 2015/2283 of the European Parliament and of the Council, and amending Commission Implementing Regulation (EU) 2017/2470". EU Commission. 2 June 2021.
Turck, Dominique; Castenmiller, Jacqueline; De Henauw, Stefaan; Hirsch‐Ernst, Karen Ildico; Kearney, John; MacIuk, Alexandre; Mangelsdorf, Inge; McArdle, Harry J.; Naska, Androniki; Pelaez, Carmen; Pentieva, Kristina; Siani, Alfonso; Thies, Frank; Tsabouri, Sophia; Vinceti, Marco; Cubadda, Francesco; Frenzel, Thomas; Heinonen, Marina; Marchelli, Rosangela; Neuhäuser‐Berthold, Monika; Poulsen, Morten; Prieto Maradona, Miguel; Schlatter, Josef Rudolf; Van Loveren, Henk; Ververis, Ermolaos; Knutsen, Helle Katrine; Knutsen, H. K. (13 January 2021). "Safety of dried yellow mealworm (Tenebrio molitor larva) as a novel food pursuant to Regulation (EU) 2015/2283]". EFSA Journal. 19 (1): 6343. doi:10.2903/j.efsa.2021.6343. PMC 7805300. PMID 33488808.
Boffey, Daniel (2021-01-13). "Yellow mealworm safe for humans to eat, says EU food safety agency". The Guardian. ISSN 0261-3077. Retrieved 2021-01-15.
"6. nutritional value of insects for human consumption" (PDF). Edible insects: future prospects for food and feed security (PDF). FAO FORESTRY PAPER. Vol. 171. FAO. 2013. pp. 67–.
Schmidt, Anatol; Call, Lisa; Macheiner, Lukas; Mayer, Helmut K. (2018). "Determination of vitamin B12 in four edible insect species by immunoaffinity and ultra-high performance liquid chromatography". Food Chemistry. 281: 124–129. doi:10.1016/j.foodchem.2018.12.039. PMID 30658738. S2CID 58651702.
Rumbos, Christos I.; Athanassiou, Christos G. (March 2021). "Insects as Food and Feed: If You Can't Beat Them, Eat Them!'—To the Magnificent Seven and Beyond". Journal of Insect Science. 21 (2): 9. doi:10.1093/jisesa/ieab019. PMC 8023366. PMID 33822126.
Jordan, Rob (29 September 2015). "Plastic-eating worms may offer solution to mounting waste, Stanford researchers discover". Stanford News Service. Stanford News Service. Retrieved 24 March 2016.
Lockwood, Deirdre (September 30, 2015). "Mealworms Munch Polystyrene Foam". Chemical and Engineering News. Retrieved 2019-02-04.
Madigral, Alexis C. (27 December 2012). "Who Was First in the Race to the Moon? The Tortoise". Atlantic. Retrieved 9 March 2019.