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]
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.
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]
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.
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.
^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.