The dung beetle fauna of the Big Bend region of Texas (Coleoptera: Scarabaeidae: Scarabaeinae)
Edmonds, W. D.
Insecta Mundi
2018
2018-07-27
642
1
30
4FSL6
Edmonds
Edmonds
1994
[192,580,490,514]
Insecta
Scarabaeidae
Phanaeus
Animalia
Coleoptera
15
14
Arthropoda
species
texensis
Fig. 70–73
Diagnosis.Black, often with blue-violet highlights; upper surface dull. Length 12–22 mm. Male ( Fig. 70–72) – Head of large individuals bearing long horn curved posteriorly over the pronotum; pronotum roughened by irregular granular sculpturing, strongly flattened, with salient, laterally curved posterior angles; in smaller males head horn shorter and triangular area of pronotum reduced in size and prominence. Female ( Fig. 73) – Head with anteriorly bowed ridge between and in front of eyes; pronotum granulate, convex, with transverse, weakly bowed ridge near anterior margin. Elytral interstriae flat, densely roughened. Edmonds (1994)provides a formal description of this species (as P. triangularis texensis; raised to species status in Edmonds and Zidek 2012).
Big Bend collection sites(altitudinal range: 1325–1850 m). Jeff Davis Co: [1] Davis Mountains Preserve, 31°41′40″N 104°07′30″W, 1850 m(Jul–Aug); [2] Davis MountainsPreserve ( Madera Canyon Unit), 1845 m( Sep); [3] 16 kmS Fort Davis(along TX 17), 30°27′48″N 103°58′59″W, 1600 m( Aug); [4] 8 km 8 kmSE Fort Davis(via TX 118), Chihuahuan Desert Research Institute( Quarry Unit), 30°32′06″N 103°50′37″W, 1480 m( Sep); [5]~ 16 kmNE Valentine, Muerto Springs Ranch( Muerto Springs), 30°40′50″N 104°20′22″W, 1555 m( Jul). Presidio Co.: [1] 37 kmSSW Marfa(along FM 2810, Petan Ranch– Cherry Hillssector), 30°07′35″N 104°19′24″W, 1630 m(Jun); [2] 20–26 kmSSE Marfa(along FM 169), 1355–1415 m( Jun); [3] 27 kmSSE Marfa(along FM 169), 30°08′42″N 104°02′13″W, 1325 m( Jul); [4]~ 16 kmW Valentine( Miller Ranch, near headquarters), 30°33°30″N 104°38′44″W, 1350 m( Jul–Aug); [5] Miller Ranch(~ 16 kmW Valentine), 30°32′50″N 104°39′40″W( Camp Holland) 1410 m( Aug); [6] 3 kmNE Marfa(along FM 1112), MarfaGolf Course, 30°19′40″N 103°59′41″W, 1470 m( Jul, Sep). Collection method(s).a) baited pitfall trap (human feces); b) direct capture (cowdung; pronghorn dung; horse dung; *deer carcass).
Surface activity.Diurnal. Habitat.Montane woodlands and grasslands throughout the Big Bend area.
Comments. Phanaeus texensisis not common in the Big Bend, but it is widespread there. It is a burrowing species that searches for food (usually dung) on the surface that, once located, is buried by bits in tunnels underneath or to the side of its find. Often the only sign that it is present is a small mound of soil pushed to the surface during excavation of the tunnel. Because it passes most of its adult life underground, this species is, in spite of its size and conspicuousness, largely unknown to ranchers, hunters and others who frequent pasturelands in the area. While it prefers montane habitats, it can be found in other grassland and scrub habitats as well, but usually above 1380 m. Big Bend specimens of this species are always darkly colored, but scarce individuals can occasionally assume metallic green/coppery coloration in eastern parts of the state. In 1994, I considered P. texensis(as P. triangularis texensis) essentially absent from the Big Bend, an error corrected here. A peripheral record in Pecos Co. about 32 kmnorthwest of Marathon on U.S.Hwy 385 (Brewster Co.), reports P. texensisfrom a deer carcass. While P. texensisoccurs throughout much of the western two-thirds of the state, including the Big Bend, another species occurs at the periphery of the Trans-Pecos and could be regarded as an incipient (or perhaps previous) member of the Big Bend fauna. This second Phanaeusis P. difformisLeConte( Fig. 74–75), which is broadly distributed in the south-central United Statesand has penetrated western areas into the northern limit of the Trans-Pecos via river drainage systems into southeastern New Mexicoand eastern Colorado( Edmonds 1994). A few isolated specimens have been collected in the Hueco Mountains east of El Paso ( Schoenly 1983) as well as in GuadalupeMountains National Park and near Malaga, New Mexico (personal records). Another common Phanaeus, P. vindexMacLeay, occurs widely in the Texas plains, New Mexico and Arizona; I agree with Bill Warner (pers. comm.) that its apparent absence from the Trans-Pecos is surprising.
2575871676
[232,1388,875,900]
31.694443
Davis Mountains Preserve
20
-104.125
Jeff Davis Co
15
14
1
2575871701
Sep
1845
Davis Mountains
Madera Canyon Unit
15
14
1
2575871613
TX
Aug
1600
30.463335
16 km S Fort Davis
20
-103.983055
15
14
TX 17
1
2575871656
TX
Sep
1480
30.535
Chihuahuan Desert Research Institute
20
-103.84361
Quarry Unit
15
14
TX 118
1
2575871620
Jul
1555
30.680555
Muerto Springs Ranch
20
-104.33945
Muerto Springs
15
14
1
2575871637
Presidio Co.
30.126389
Petan Ranch
20
-104.32333
Marfa
15
14
1
2575871696
[543,1305,1069,1093]
FM
Jun
1385
20 - 26 km SSE Marfa
15
14
FM 169
1
2575871700
FM
Jul
1325
30.145
27 km SSE Marfa
20
-104.03694
15
14
FM 169
1
2575871687
Jul-Aug
1350
Miller Ranch
-104.64555
15
14
1
2575871604
Camp & Aug
Netherlands
1410
30.547222
Miller Ranch
20
-104.66111
15
14
1
2575871699
FM
Jul & Sep
Netherlands
1470
30.327778
Marfa
20
-103.99472
15
14
FM 1112
1