An unsystematic catalog of the Coleopteran fauna in the environment surrounding the lab, biased toward the most common and easy to photograph. Because my research has focused on the Tenebrionids, they are currently the best described. Time permitting, other groups will receive appropriate attention.
A few species have links to pages of their own.
Click images to enlarge.
Family Carabidae: Ground and Tiger Beetles:
Tiger Beetles: Cicindelinae
Great Plains giant tiger beetle, Amblycheila cylindriformis.
Family Cerambycidae: Longhorn Beetles
Black cactus longhorn beetles (Moneilema appressum)live among cholla cactus. Their larvae burrow inside the cactus, feeding on roots and stems. Adults of some species are convincing mimics of Eleodes longicollis.
Family Meloidae: Blister Beetles
Oil beetles in the genus Meloe are so named for the defensive secretions they release from their joints. They feed on foliage as adults, but are parasitic on native bees as larvae.
Family Silphidae: Burying and Carrion Beetles
As the name indicates, burying beetles prepare and bury vertebrate carcasses to provide a food source for their larvae.
Family Tenebrionidae: The Darkling Beetles
Eleodes:
“…stay away from Eleodes; you can’t tell where one species leaves off and another begins.” Professor Josef Knull, Quoted in Triplehorn and Thomas, 2015, Trans Am Ent Soc 137: 251.
The genus Eleodes comprises flightless beetles in the family Tenebrionidae. All have defensive glands in the posterior abdomen that produce noxious chemicals that can be deployed against threats. There are at least six species of Eleodes commonly found around the lab. Some are easy to identify, others not so much.
To help me keep things straight, I have included the subgenus of each species (in parentheses), diagnostic characters, and relevant references below. You are welcome to ignore them.
Eleodes (Melaneleodes) carbonaria
Size: 12-20 mm
Mass: ~500 mg
Subfamily: Blaptinae
Chemical Defense: Abdominal glands
Season: Late April to early October
General Description: Smallish, common beetle. The most common of the local variants resembles a small E. longicollis, but E. carbonaria has orderly rows of small puncta on the elytra.
Species page
Eleodes (Eleodes) caudifera
Size: 22-30 mm
Mass: not measured yet
Subfamily: Blaptinae
Chemical Defense: Abdominal glands
Season: April to September
General Description: Medium-sized Eleodes, distinguished from all other local beetles by “tail” extending from the elytra. Elytra grooved, “shoulders” on pronotum.
Species page
Eleodes (Litheleodes) extricata
Size: 11-15 mm
Mass: ~150 mg
Subfamily: Blaptinae
Chemical Defense: Abdominal glands
Season: May to August
General Description: Smallest local species. The elytra are slightly rugose, or roughened, compared to the larger E. carbonaria or E. longicollis.
Species page
Eleodes (Eleodes) hispilabris
Size: 18-29 mm
Mass: ~750 mg
Subfamily: Blaptinae
Chemical Defense: Abdominal glands
Season: April to September
General Description: medium-sized species with ridged elytra. Common and widespread in west. Distinguished from similar species by narrow “waist,” lack of “tails” (E. caudifera) and/or smaller size (E. obscura).
Species page
Eleodes (Steneleodes) longicollis
Size: 25-35 mm
Mass: ~1 g
Subfamily: Blaptinae
Chemical Defense: Abdominal glands
Season: Late March to October
General Description: Possibly the most common species, found from spring through fall. Readily stands on its head when approached. Distinguished from other Eleodes by its relatively long, narrow appearance and smooth, shiny elytra.
Species page
Eleodes (Eleodes) obscura
Size: 28-35 mm
Mass: ~1.4 g
Subfamily: Blaptinae
Chemical Defense: Abdominal glands
Season: April to September
General Description: Eleodes (Eleodes) obscura is the largest species found in the area. Elytra are rough and slightly ridged.
Eleodes (Melaneleodes) tricostata
Size: 13-23 mm
Mass: not known
Subfamily: Blaptinae
Chemical Defense: Abdominal glands
Season: Observed in August, but full range unknown.
Relatively rare. Easily distinguished from other Eleodes species by the three prominent ridges running the lengths of the elytra. The pronotum is also flat, rough and lumpy.
Embaphion contusum
Size: ~15 mm
Mass: not known
Subfamily: Blaptinae
Chemical Defense: Abdominal glands
Season: Observed in April and July.
General description: Very rare in the neighborhood of the lab. Elaborate “shoulders” on the thorax, and the ridge around the edges of the elytra make this beetle difficult to mistake for any species except possibly S. opaca.
Eusattus species
Size: [~15 mm]
Mass: not known
Subfamily: Pimeliinae
Chemical Defense: None
Season: July and August
General description: Uncommon. Eusattus beetles are small, nearly circular from above, and dome-shaped in profile.
Philolithus elatus
Size: 21-35 mm
Mass: ~1.2 g
Subfamily: Pimeliinae
Chemical Defense: regurgitation
Seasonality: Late July to early October
General Description: One of the largest local Tenebrionids. Rough, weakly ridged elytra resembling E. obscura, of which it is considered a mimic. Found on roads and trails, frequently in association with harvester ants (Pogonomyrmex). Until 2013, it was in its own genus, Gonasida.
More detailed information in the Philolithus elatus page.
Stenomorpha
There are several local species of Stenomorpha, most appearing in late summer and fall. They are also Tenebrionids, but like all members of the subfamily Pimeliinae, do not have defensive glands. Some species are thought to be mimics of Eleodes. The genus has received less attention than Eleodes, making definitive identification more challenging.
Stenomorpha obovata
Size: 15-20 mm
Mass: not measured
Subfamily: Pimeliinae
Chemical Defense: none
Seasonality: July to September
General Description: Medium-small beetle, with smooth elytra that bulge slightly making a crease in the middle. Ridge around the edge of the pronotum.
Stenomorpha opaca
Size:
Mass:
Subfamily: Pimeliinae
Chemical Defense: none
Seasonality: July to September
General Description: Relatively common. Identifiable based on the rough, broad pronotum and strongly ridged elytra
Stenomorpha rimata
Size: ~27 mm
Mass: 1.2 g
Subfamily: Pimeliinae
Chemical Defense: none
Seasonality: Late August to late October
General Descripion: Stenomorpha rimata is larger than others in the genus, and the elytra are heavily dimpled without visible ridges. They are active after the rest of the Tenebrionids have disappeared for the season. Very similar to S. marginata, and they may eventually be merged into the same species.
More information on the Stenomorpha marginata/rimata page.