Desert stink beetle facts for kids
Quick facts for kids Desert stink beetle |
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| Eleodes armata | |
Scientific classification  |
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| Kingdom: | Animalia |
| Phylum: | Arthropoda |
| Class: | Insecta |
| Order: | Coleoptera |
| Family: | Tenebrionidae |
| Tribe: | Amphidorini |
| Genus: | Eleodes Eschscholtz, 1829 |
| Type species | |
| Eleodes dentipes Eschscholtz, 1829
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| Subgenera | |
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See text |
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| Map of North America with the range of Eleodes highlighted in dark grey. | |
Eleodes (commonly known as pinacate beetles or desert stink beetles) is a genus of darkling beetles, in the family Tenebrionidae. They are endemic to western North America ranging from southern Canada to Mexico with many species found in the Sonoran Desert and Southern California. Some species have been introduced to Colombia. The name pinacate is Mexican Spanish, derived from the Nahuatl (Aztec) name for the insect, pinacatl, which translates as "black beetle."
Eleodes species range from about 10 to 50 millimeters in length and are black in color with some having a reddish tint on their abdomen. The setae of some species such as Eleodes osculans collect debris and give the insect a brown color, a similar effect occurs in the species Eleodes mirabilis giving it the appearance of having whitish stripes on its abdomen. Due to the number of species and their large range these beetles have a fairly varied appearance among the differing species. All produce quinone or similar substances as a deterrent to predators, and many will stand on their heads to spray it. They are typically found in the arid desert regions of their range but can also be found in forests and grasslands. All Eleodes species are flightless as their elytra are fused together and their second pair of wings is very reduced and vestigial.
Contents
Ecology
Most members of the genus Eleodes are primarily detrivores feeding on plant and animal debris, some species are more inclined to consume living plants which is especially true for species native to the plains of North America such as Eleodes hispilabris and Eleodes opaca. The larvae of those species and others are considered pests as they feed on the roots of crops.
Species found in dry regions such as members of the subgenus Eleodes are usually much larger than what is expected for most insects, this is due the lack of water in the area leading to these beetles evolving larger bodies in order to hold more of it. Water loss is also the reason that the elytra are fused in Eleodes. As expected, species found in forests, such as members of the subgenus Blapylis are smaller, closer to the size of most other insects.
Eleodes are generally more active at night, some species are strictly nocturnal while others can and will be active during the day. As these beetles are fairly long lived when it comes to insects they must adapt to the different seasons, when fall and winter come members of Eleodes will be more active during the day as to not freeze during the night. When summer arrives they will be much more active at night when compared to day as the heat of the sun in the deserts where they are most common can be deadly. One subgenus, Caverneleodes, lives exclusively in caves, cave-like environments, or rock crevices, these beetles have reduced eyes and only leave their hideouts during the night to scavenge for food.
Chemical Defense
Beetles within Eleodes and other genera within Tenebrionidae exude a foul smelling odor and a very distasteful liquid from glands to ward off predators. This liquid is most commonly a form of quinone. While not being poisonous the liquid does usually deter predators, the success of this defense mechanism has lead to the evolution of a Müllerian mimicry complex among Eleodes acuticauda, Eleodes dentipes, and Coelocnemis magna, the latter of which while not being within Eleodes is a still distasteful prey item. All three previously mentioned species look strikingly similar leading to a strengthened defense against potential predators. Another Müllerian mimicry complex exists between Eleodes scabrosa and Eleodes tuberculata.
While this defense is generally effective in deterring predators, they are still preyed upon by many species, such as owls, foxes, coyotes, skunks, bats, turtles, etc.
Fossil Record and Evolution
Fossils of Eleodes acuticauda, Eleodes osculans, Eleodes carbonaria, Eleodes granulata, Eleodes gracilis, and others have been found in the La Brea Tar Pits, Carpinteria Tar Pits, and the Snowmastodon Site which are all dated to the Pleistocene epoch. Eleodes likely evolved before the Pleistocene, probably in the late Miocene or Pliocene.
Theoretical Evolution
It has been theorized that since the subgenus Blapylis resembles non-Eleodes members of the tribe Amphidorini, it might be the most ancient subgenus within Eleodes and the earliest species within Eleodes could have resembled members of Blapylis more than any of the other subgenera. Eleodes could have evolved before the beginning of the Quaternary glaciations as a genus exclusive to the vast forests of western North America, as the continent was dominated by them up tens of thousands of years ago. When the ice ages began and the plains and deserts slowly grew across western North America, some members of Eleodes could have evolved to fit the new niches appearing in the dryer, less lush parts of North America, these beetles would get larger in order to hold more water and they would go on to form new subgenera within Eleodes and define the genus as what it is today.
Taxonomy
Eleodes is the largest New World genus of darkling beetles comprising around 200 species divided up into the following 16 subgenera.
- Subgenus Amphidora Eschscholtz, 1829
- Subgenus Blapylis Horn, 1870
- Subgenus Caverneleodes Triplehorn, 1975
- Eleodes easterlai Triplehorn, 1975
- Eleodes gruta Aalbu, Smith & Triplehorn, 2012
- Eleodes guadalpensis Aalbu, Smith & Triplehorn, 2012
- Eleodes labialis Triplehorn, 1975
- Eleodes leptoscelis Triplehorn, 1975
- Eleodes microps Aalbu, Smith & Triplehorn, 2012
- Eleodes reddelli Triplehorn, 2007
- Eleodes rugosifrons Triplehorn & Reddell, 1991
- Eleodes sprousei Triplehorn & Reddell, 1991
- Eleodes thomasi Aalbu, Smith & Triplehorn, 2012
- Eleodes wheeleri Aalbu, Smith & Triplehorn, 2012
- Eleodes wynnei Aalbu, Smith & Triplehorn, 2012
- Subgenus Chaseleodes Thomas, 2015
- Subgenus Cratidus LeConte, 1862
- Subgenus Discogenia LeConte, 1866
- Subgenus Eleodes Eschscholtz, 1829
- Eleodes suturalis (Say, 1824)
- Eleodes acuta (Say, 1824)
- Eleodes obscura (Say, 1824)
- Eleodes vanduzeei Blaisdell, 1923
- Eleodes loretensis Blaisdell, 1923
- Eleodes armata LeConte, 1851
- Eleodes moesta Blaisdell, 1921
- Eleodes femorata LeConte, 1851
- Eleodes grandicollis Mannerheim, 1843
- Eleodes sanmartinensis Blaisdell, 1921
- Eleodes acuticauda LeConte, 1851
- Eleodes dentipes Eschscholtz, 1829
- Eleodes rugosa Perbosc, 1839
- Eleodes fiski Triplehorn, 2015
- Eleodes samalayucae Triplehorn, 2007
- Eleodes hispilabris (Say, 1824)
- Eleodes sponsa LeConte, 1858
- Eleodes adumbrata Blaisdell, 1925
- Eleodes mirabilis Triplehorn, 2007
- Eleodes scyroptera Triplehorn, 2007
- Eleodes muricatula Triplehorn, 2007
- Eleodes rossi Blaisdell, 1943
- Eleodes gracilis LeConte, 1858
- Eleodes curvidens Triplehorn & Cifuentes-Ruiz, 2011
- Eleodes eschscholtzii Solier, 1848
- Eleodes subcylindrica Casey, 1890
- Eleodes discincta Blaisdell, 1925
- Eleodes tenuipes Casey, 1890
- Eleodes mexicana Blaisdell, 1943
- Eleodes spinipes Solier, 1848
- Subgenus Heteropromus Blaisdell, 1909
- Subgenus Litheleodes Blaisdell, 1909
- Eleodes arcuata Casey, 1884
- Eleodes hirtipennis Triplehorn, 1964
- Eleodes aspera LeConte, 1866
- Eleodes letcheri Blaisdell, 1909
- Eleodes extricata (Say, 1824)
- Eleodes papillosa Blaisdell, 1917
- Eleodes corvina Blaisdell, 1921
- Eleodes subtuberculata Walker, 1866
- Eleodes granulata LeConte, 1857
- Subgenus Melaneleodes Blaisdell, 1909
- Eleodes tricostata (Say, 1824)
- Eleodes neomexicana Blaisdell, 1909
- Eleodes pedinoides LeConte, 1858
- Eleodes wenzeli Blaisdell, 1925
- Eleodes parowana Blaisdell, 1925
- Eleodes halli Blaisdell, 1941
- Eleodes carbonaria (Say, 1824)
- Eleodes quadricollis Eschscholtz, 1829
- Eleodes anthracina Blaisdell, 1909
- Eleodes humeralis LeConte, 1857
- Eleodes rileyi Casey, 1891
- Subgenus Metablapylis Blaisdell, 1909
- Subgenus Omegeleodes Triplehorn & Thomas, 2011
- Eleodes debilis LeConte, 1858
- Subgenus Promus LeConte, 1862
- Subgenus Pseudeleodes Blaisdell, 1909
- Eleodes caudifera LeConte, 1858
- Eleodes granosa LeConte, 1866
- Eleodes leechi Tanner, 1961
- Eleodes longipilosa Horn, 1891
- Eleodes pilosa Horn, 1870
- Eleodes inornata Johnston, 2016
- Eleodes spoliata Blaisdell, 1933
- Eleodes tribulus Thomas, 2005
- Subgenus Steneleodes Blaisdell, 1909
- Subgenus Tricheleodes Blaisdell, 1909
- Eleodes hirsuta LeConte, 1861
See also
In Spanish: Eleodes para niños
