Arianops obrieni, Carlton, 2008

Carlton, Christopher E., 2008, Eight New Species ofArianopsBrendel from the Southeastern United States with an Updated Key and Notes on Additional Species (Coleoptera: Staphylinidae: Pselaphinae), The Coleopterists Bulletin 62 (2), pp. 297-323 : 297-323

Arianops obrieni , new species

( Figs. 1–2 , 17–18 )

Holotype female ( Figs. 1–2 ). / Tex. Tyler Co., Big Thicket Nat. Pres. 21 Fe. 2004, C. W O’Brien & R. Turnbow / Beechwood Tr. Sifted beech litter/ Arianops obrieni Carlton, 2007 Holotype female/. Type deposition, Field Museum of Natural History, Chicago, IL .

Etymology. This species is named for C. W. O’Brien, co-collector of the holotype and preeminent curculionid systematist.

Description. Holotype female. Measurements (in mm): head 0.45 long, 0.45 wide; pronotum 0.45 long, 0.50 wide; elytra 0.50 long, 0.60 wide; median lengths of visible abdominal tergites 1–5, respectively 0.30, 0.10, 0.10, 0.40, 0.10. Antennomeres 1–11, respectively 0.15, 0.10, 0.10, 0.08, 0.08, 0.08, 0.05, 0.05, 0.08, 0.07, 0.20. Total length 2.30.

Head ( Fig. 17 ). Lateral vertexal carinae well-developed from antennal tubercles to the level of the vertexal foveae. Median occipital carina present from posterior declivity of occiput to approximately level of the vertexal foveae. Vertexal foveae normally developed, connected via well defined u-shaped circumambient sulcus that broadens only slightly between antennal insertions. Carinae to antennal tubercles extending to clypeus, almost to margin; clypeus not carinate medially. Labral margin bearing four approximately equal teeth. Lateral carinae from clypeus to ocular spines well-developed and continuous with spines, which are large, triangular, and oriented laterally.

Pronotum. Basomedian fovea present, located in shallow depression between a pair of low, submedian spines. One pair of weak basolateral foveoid depressions present, with possible additional depressions obscured by transversely rugose microsculpture along basolateral margin. A pair of well-developed foveae present on postlateral flanks of pronotum.

Elytra. Basal margin of each elytron slightly angled from suture to humeral declivity. Basal depressions and foveae absent.

Legs. Unmodified.

Abdomen. Weakly convex dorsally, more strongly convex ventrally, lateral margin subparallel to posteriad of tergite 3 then convergent to apex. Tergite 5 deflexed, not visible in dorsal view. Ventrite 5 with a small, blunt median cusp along margin. Ventrite 6 broadly, weakly concave, with a rounded, carinoid tumulus in apical one-third ( Fig. 18 ).

304 4) A. carteri .

Male. Unknown.

Material examined. Only the holotype is known.

Distribution. The species is only known from the type locality in Tyler County, Texas.

8) A. ashei .

Comments. The occurrence of this species on the western Gulf Coastal Plain of east Texas was unexpected. The area is known as the Big Thicket and includes extensive tracts of pine-hardwood flatwoods and mixed mesophytic forest habitats. The specimen was collected from the latter habitat type. Charles O’Brien (pers. comm.) provided the following comment about the collecting

306 event: ‘‘We walked along the trail and took about 5 stops sifting litter in depressions and around beech tree buttresses.’’ During July 2007 I visited the area and attempted to collect additional specimens by collecting a series of six litter samples from various points along the trail, but without success. Additional collecting during winter and spring will likely be necessary. The Big Thicket area was heavily impacted by Hurricane Rita during September 2005 and is dramatically different from the time O’Brien and Turnbow collected the holotype during 2004 .

Nantahala species group

Figures

Figs. 1–4. Dorsal and lateral views, Arianops new species holotypes. 1–2) A. obrieni; 3–

Figs. 17–27. Arianops new species. 17) A. obrieni, head; 18) A. obrieni, female ventrites 5–6; 19) A. carteri, head; 20) A. carteri, mesothoracic coxa-femur; 21) A. clintoni, head; 22) A. clintoni, mesothoracic coxa-femur; 23) A. clintoni, ventrites 3–4; 24) A. ashei, head; 25) A. ashei, ventrites 3–4; 26) A. barri, head; 27) A. barri, ventrites 3–4.