Eustrophopsis indistinctus (LeConte, 1851)

Pollock, Darren A., 2012, Review of the Eustrophinae (Coleoptera, Tetratomidae) of America north of Mexico, ZooKeys 188, pp. 1-153 : 20-21

Eustrophopsis indistinctus (LeConte, 1851) Figures 8213345515459647176

Eustrophus indistinctus LeConte 1851: 151.-("Colorado [River]"); Melsheimer 1853: 143; Crotch 1873: 112; Henshaw 1885: 124; Snow 1885: 69; Horn 1888: 34.

Eustrophinus indistinctus (LeConte).- Leng 1920: 238; Csiki 1924: 8; LeSage 1991: 246; Poole and Gentili 1996: 299.

Eustrophopsis indistinctus (LeConte).- Pollock 2008: 290.

Diagnosis.

This is the only species of Eustrophopsis with a distinctly brown dorsal color; other diagnostic features include: antennomeres 1-4 and 11 not very distinctly contrasting in color with 5-10; eyes distinctly separated dorsally; pronotal punctation (especially compared with Eustrophopsis bicolor ) relatively coarse.

Description.

TL 4.9-6.2 mm; GEW 2.4-3.0 mm. Body elongate oval (Fig. 8), moderately tapered posteriorly, distinctly convex dorsally (Fig. 21); dorsal color light to dark brown, vestiture also brownish; antennomeres 1-4 and 11 light to dark rufous, antennomeres 5-10 dark, piceous; venter rufous to brown, legs somewhat lighter in color than that of ventral sclerites; eyes moderately widely separated dorsally (Fig. 33), distance between eyes greater than maximum width of antennomere 1; eyes deeply emarginated around antennal insertions; antennae relatively long, with no discernible sexual dimorphism; all antennomeres longer than wide; antennomeres 5-10 slightly widened, submoniliform; antennal sensilla completely annular; last maxillary palpomere elongate, unmodified, apex slightly oblique; pronotal punctation moderately coarse; prosternal process (Fig. 45) elongate, narrowly rounded distally, extended to slightly anterior of posterior margin of procoxae; prothoracic episternal suture present, surface of proepisternum smooth, punctures not obscured by rugose macrosculpture; coarse elytral punctures forming multiple striae; meso- and metatibiae with numerous, oblique ridges; male with small, ovate, setiferous pit on ventral edge of profemur; aedeagus (Figures 59, 64) with basal piece of tegmen distinctly longer than apical piece; struts on median lobe wide, long, inner margins V-shaped; sternite 9 basally broadly U-shaped.

Distribution

(Figures 71, 76). The range of this species is decidedly southwestern with most specimens from Arizona and New Mexico; southeastern Colorado is the northern extent. To the south, the species is known from northwestern Mexico. The 295 specimens examined were from the following jurisdictions: MEXICO: BAJA CALIFORNIA SUR, CHIHUAHUA. UNITED STATES: ARIZONA: Cochise, Gila, Graham, Greenlee, Maricopa, Pima, Pinal, Santa Cruz, Yavapai. COLORADO: Bent. NEW MEXICO: Bernalillo, Eddy, Roosevelt, Sierra. OKLAHOMA: Cimarron. TEXAS: Aransas, Blanco, Brewster, Cameron, Harris. (Complete label data given in Appendix 1).

Types.

Eustrophus indistinctus LeConte. SYNTYPE, sex unknown, labeled "gold disk / Type 4779 / Eustrophus indistinctus Lec." Specimen with gold disk (indicative of California); the “Colorado” referred to in the description is actually the Colorado River, and not the state.

Natural history.

Fungi (AZ); on bracket fungus (AZ); ex fungus on dying willow (NM); on dead log at night (NM); at night on fungusy logs (NM); at fungi on burned Populus snags (NM); fungi on Salix (AZ).

Notes.

This species was one of the earliest described Nearctic eustrophines; however, it was synonymized early on with Eustrophopsis bicolor by Horn (1888: 34) who stated that "specimens collected by me in very early spring, in Arizona, have a decidedly brownish color above...These are probably merely less mature specimens as no other structural differences have been observed". This synonymy was followed by subsequent authors, e.g. Csiki (1924) and Poole and Gentili (1996). In fact, the relatively lighter coloration is one of the diagnostic features of adults of Eustrophopsis indistinctus . Therefore, Eustrophopsis indistinctus has been removed from synonymy with Eustrophopsis bicolor and re-established as a distinct species. There remains some difficulty in distinguishing southern specimens of Eustrophopsis bicolor from Eustrophopsis indistinctus (see “notes” for Eustrophopsis bicolor , above).