Darkling beetle

Darkling beetle Temporal range: Late Jurassic–Recent PreꞒ Ꞓ O S D C P T J K Pg N
Alphitobius sp. (Tenebrioninae: Alphitobiini) Scale bar (top right) is 2 mm
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
Order:	Coleoptera
Suborder:	Polyphaga
Infraorder:	Cucujiformia
Superfamily:	Tenebrionoidea
Family:	Tenebrionidae Latreille, 1802
Subfamilies
See text
Synonyms
Alleculidae

Darkling beetle is the common name for members of the beetle family Tenebrionidae, comprising over 20,000 species in a cosmopolitan distribution.

Taxonomy

Tenebrio is the Latin generic name that Carl Linnaeus assigned to some flour beetles in his 10th edition of Systema Naturae 1758-59. ^[1] The name means "lover of darkness"; ^[2] the English language term 'darkling' means "characterised by darkness or obscurity"; ^[3] see also English 'tenebrous', figuratively "obscure, gloomy." ^[4]

Many Tenebrionidae species inhabit dark places; in genera such as Stenocara and Onymacris, they are active by day and inactive at night.

The family covers a varied range of forms, such that classification presents great difficulties. These eleven subfamilies were listed in the 2021 review by Bouchard, Bousquet, et al., updating a similar catalog from 2005. ^{[5] [6]}

• Alleculinae Laporte, 1840
• Blaptinae Leach, 1815
• Diaperinae Latreille, 1802
• Kuhitangiinae G.S. Medvedev, 1962
• Lagriinae Latreille, 1825
• Nilioninae Oken, 1843
• Phrenapatinae Solier, 1834
• Pimeliinae Latreille, 1802
• Stenochiinae Kirby, 1837
• Tenebrioninae Latreille, 1802
• Zolodininae Watt, 1975

Ongoing phylogenetic studies are showing that some taxonomic changes are needed. For instance the tribal classification of tribe Pedinini has recently been altered. ^[7]

The misspelling "Terebrionidae" occurs frequently enough to be easily overlooked. ^{[8] [9]} The error appears to have no particular significance, but to be the product of misreadings, mis-scans and mis-typings.

Tenebrionidae head

The oldest known member of the family is Jurallecula from the Late Jurassic Karabastau Formation of Kazakhstan, assigned to the subfamily Alleculinae.

Characteristics

The Tenebrionidae may be identified by a combination of features, including:

• Their eleven-segmented antennae that may be filiform, moniliform or weakly clubbed
• First abdominal sternite is entire and not divided by the hind coxae
• Eyes notched by a frontal ridge
• Four segments in the hind pair of tarsi and five in the fore and mid-legs (5-5-4), with simple claws

Biology and ecology

Tenebrionid beetles occupy ecological niches in mainly deserts and forests as plant scavengers. Most species are generalistic omnivores, and feed on decaying leaves, rotting wood, fresh plant matter, dead insects, and fungi as larvae and adults. ^[10] Several genera, including Bolitotherus, are specialized fungivores which feed on polypores. Many of the larger species are flightless, and those that are capable, such as T. molitor, often rarely do so. ^{[11] [12] [13]}

A tenebrionid larva ( Eleodes sp.)

The larvae, known as mealworms or false wireworms, are usually fossorial, heavily sclerotized and nocturnal. They may possibly be an important resource for certain invertebrates and small mammals. Adults of many species have chemical defenses and are relatively protected against predators. ^[12] Adults of most species, except grain pests, have slow metabolisms, and live long lives compared to other insects, ranging from approximately six months to two years.

Some species live in intensely dry deserts such as the Namib, and have evolved adaptions by which they collect droplets of fog that deposit on their elytra. As the droplets accumulate the water drains down the beetles' backs to their mouthparts, where they swallow it. ^[14]

Humans spread some species such that they have become cosmopolitan, such as Tribolium castaneum , the red flour beetle, which was spread through grain products.

Notable types

The larval stages of several species are cultured as feeder insects for captive insectivores or as laboratory subjects:

• Tenebrio molitor , or mealworm, is commonly used to feed terrestrial amniotes kept in terraria.
• Tribolium castaneum is a laboratory animal useful as a model organism, especially in studies of intragenomic conflict and population ecology.
• Zophobas morio , or superworm, is valued as a feed for captive reptiles; it contains less chitin than Tenebrio molitor.
• Alphitobius diaperinus , lesser mealworm ^[15]
• Many tenebrionids are pests of cereal and flour silos and other storage facilities, including T. castaneum, other Tribolium species such as Tribolium confusum and Tribolium destructor , and Gnathocerus cornutus .
• In southwestern North America, species of the genus Eleodes (particularly E. obscurus) are well known as "pinacate beetles" or "desert stink beetles".
• Several genera, such as Stenocara and Onymacris, are of interest in ecological studies of arid conditions and their associated adaptations.
• Ulomoides dermestoides , known as "chinese weevil", "peanut beetle", "cancer beetle", or "asthma beetle", is eaten in Argentina where it is thought to be a treatment for cancer, asthma, and other illnesses.

Further information: Luprops tristis

Gallery

• 
  Diaperis boleti under bark of oak.
• 
  Lagria sp. (Lagriinae) in Tanzania
• 
  Platynotus excavatus , India
• 
  Stenocara dentata in southern Africa
• 
  Gonopus tibialis
• 
  Pie dish beetle, Helea sp. in Australia
• 
  Hegemona sp. (De Laporte, 1840) from Belize
• 
  Neomida bicornis , male
• 
  Neomida bicornis, female
• 
  Meracantha contracta , USA

References

1. Linnaeus, Carl (1759). "Caroli Linnæi ... Animalium specierum in classes, ordines, genera, species, methodica dispositio ." (in Latin). Leiden: Theodor Haak. p. 134.
2. Jaeger, Edmund Carroll (1978) [1959]. A source-book of biological names and terms (6th printing, 3rd ed.). Springfield, IL: Charles C. Thomas. p. 259. ISBN   0398009163.
3. Brown, Lesley, ed. (1993). The New shorter Oxford English dictionary on historical principles, Vol. 1, A–M . Oxford: Clarendon Press. p. 594. ISBN   0198612710.
4. Onions, C. T., ed. (1973). The shorter Oxford English dictionary on historical principles, Vol. 2, N-Z (Reset with revised etymologies and addenda, 3rd ed.). Oxford: Clarendon Press. p. 2261. ISBN   978-0-19-861116-5.
5. Bouchard, Patrice; Bousquet, Yves; Aalbu, Rolf L.; Alonso-Zarazaga, Miguel A.; et al. (2021). "Review of genus-group names in the family Tenebrionidae (Insecta, Coleoptera)". ZooKeys (1050): 1–633. doi: 10.3897/zookeys.1050.64217 . hdl: 10261/250214 . PMC   8328949 . PMID   34385881.
6. Bouchard, Patrice; Lawrence, John F.; Davies, Anthony E.; Newton, Alfred F. (2005) "Synoptic Classification of the World Tenebrionidae (Insecta: Coleoptera) with a Review of Family-Group Names". Annales Zoologici (Warszawa), 55(4): 499–530.
7. Kamiński, M.J.; Kanda, K.; Lumen, R.; Smith, A.D.; Iwan, D. (2019). "Molecular phylogeny of Pedinini (Coleoptera, Tenebrionidae) and its implications for higher-level classification". Zoological Journal of the Linnean Society. 185 (1): 77–97. doi:10.1093/zoolinnean/zly033.
8. Dennis S. Hill (1997). The Economic Importance of Insects. Springer Science & Business Media. pp. 109–. ISBN   978-0412498008.
9. "Egyptian Beetle (Blaps polychresta) - by Graeme Ruck - JungleDragon". www.jungledragon.com. Retrieved 2023-02-02.
10. "Species Bolitotherus cornutus – Forked Fungus Beetle".
11. Flying Mealworm Beetle (Tenebrio molitor) on YouTube
12. "Family Tenebrionidae - Darkling Beetles". bugguide.net. Retrieved 2023-02-02.
13. "Bolitotherus cornutus". Archived from the original on 2016-03-04. Retrieved 2015-08-14.
14. "Desert beetles inspire aircraft design that doesn't freeze". ZME Science. 2016-01-25. Retrieved 2016-01-27.
15. Alphitobius diaperinus, lesser mealworm. University of Florida IFAS

External links

• Tenebrionidae.net- information and pictures about darkling beetles