Oedichirus hamatus, Herman, 2013

Herman, Lee H., 2013, Revision Of The New World Species Of Oedichirus (Coleoptera: Staphylinidae: Paederinae: Pinophilini: Procirrina), Bulletin of the American Museum of Natural History 2013 (375), pp. 1-137 : 90-92

Oedichirus hamatus , new species

Figures 40 , 157–159

TYPE MATERIAL: Holotype: Female. ‘‘ Peru: Colonia Cal-leria, Rio Calleria, 15km E Ucayali, 1- 15-X-1961,/FMHD # 61 - 3002, sweeping in for. at night, B. Malkin/ Holotype Oedichirus hamatus Herman. ’’ Deposited in Field Museum of Natural History. (The right profemur, protibia, and protarsus are missing.)

TYPE LOCALITY: Peru: Ucayali: Colonia Calleria (5 Callaría), Río Calleria (5 Callaría), 15 km E Ucayali (08 ° 019S, 74 ° 349W). (On the locality label the site is reported as ‘‘Colonia Calleria,’’ but that may be a misspelling for ‘‘Callaría.’’ Neither Colonia Calleria, Colonia Callaría, nor a town named Ucayali were found in gazetters or atlases, but there is a Río Ucayali east of which three old atlases [ Ambrosius, 1914; Bartholomew, 1922; Haack, 1925] cite ‘‘Callaria’’ on the bank of a small river that flows into the Ucayali. One of the three atlases [ Haack, 1925] refers to the tributary as Río Callaría. In one atlas [ Ambrosius, 1914] Callaría is cited with the symbol, signifying ‘‘ruins or historical site.’’ Diamond and Terborgh [1967: 273] travelled 20–30 miles [32–48 km] upstream on Río Callaría searching for birds; they reported the coordinates of the mouth of the river as 08 ° 089S, 74 ° 389W. Although they mentioned three small Indian villages with plantations and travelled sufficiently far upstream to have passed the collection site for O. hamatus , they referred to no town, village, plantation, or site as Callaría. Lamas [1976] reported Callaría at 08 ° 019S, 74 ° 349W; the source of those coordinates was not stated.)

DIAGNOSIS: Oedichirus hamatus is one of only six species with paratergite III; the other five are O. batillus , O. bicristatus , O. isthmus , O. optatus , and O. sinuosus . Of the six, only O. hamatus has dark femorotibial maculations (as in fig. 2). The pronotum is sparsely punctate and the punctures of the submedial row are deep and coarse. The elytra are coarsely punctate, the surface of the disc slightly concave, and the length and width are equal.

Oedichirus hamatus is the only New World species with a flat spur on the ventromedial edge of tergum IX (fig. 158). The anteroventral angles of tergum IX are separated medially. The median gonocoxal plate anteriad of the vulvar plate is reduced to a narrow strap (fig. 157). Unlike any other species, the anterior vulvar lobe of the vulvar plate (fig. 159) is densely wrinkled and most of the surface of the posterior vulvar lobe has a reticulate covering. The male is unknown, but perhaps the flat spur on the ventromedial margin of tergum IX of the holotype is not a sexually dimorphic feature.

DESCRIPTION: Length: 8.9 mm. Length of head: 0.9 mm. Width of head: 1.0 mm. Pronotal length: 1.3 mm. Pronotal width: 1.1 mm. Elytral length: 1.3 mm. Elytral width: 1.3 mm.

Color black and reddish brown. Head and prothorax black with reddish-brown-infusions. Elytra reddish brown. Abdomen dark reddish brown with paler reddish brown infusions. Legs bicolored, yellowish brown with dark reddish brown femorotibial maculation (as in fig. 2).

Head across eye wider than long (HW/HL: 1.2). Frontoclypeal ridge incomplete, medial ends narrowly separated. Dorsal surface without V-shaped depression; punctation coarse and sparse medially, finer adjacent to margin of eye, most dense anteromedially between eyes and less dense anteriorly and basally; surface polished. Labrum quadridentate, without tubercle near submedial denticle.

Pronotum about a tenth longer than wide (PL/PW: 1.1). Pronotum polished, with coarse punctation in scattered clusters and with large impunctate spots; surface with deep, submedial, punctate groove. Elytra with length and width equal (EW/EL: 1.0); surface of disc slightly concave medially and coarsely punctate.

Abdominal terga III to VI with transverse subapical rows of punctures; terga VII and VIII more evenly punctate. Segment III with paratergite. Tergum III with median point extending from transverse basal ridge. Tergum VIII with posterior margin broadly and moderately deeply emarginate; transverse basal ridge without median point. Tergum IX with lateroapical process about three fifths longer than midbasal length (LLaP/ T9: 1.6), slightly bent ventrally, and moderately divergent from other process; ventromedial margin with apically acute spur extending posteriorly to about level of posterior margin of median gonocoxal plate (figs. 157, 158).

FEMALE: Sterna III to VII unmodified. Sternum VIII with posterior margin broadly and shallowly sinuate; transverse basal ridge moderately curved anteriorly and without median point. Tergum IX with anteroventral angles separated medially (fig. 157). Median gonocoxal plate anteriad of vulvar plate reduced to narrow strap and separated from tergum IX (fig. 157); anterior margin slightly flattened then sloped lateroposteriorly; gonocoxal plate posteriad of vulvar plate tapered to broadly rounded posterior margin. Vulvar plate embedded anteriorly in median gonocoxal plate (fig. 159). Proximal vulvar lobe transverse, posterior margin broadly sinuate, and surface strongly wrinkled (fig. 159). Distal vulvar lobe transverse; surface reticulate. Vulva transversely oriented.

MALE: Unknown.

ETYMOLOGY: The name is from the Latin hamatus , ‘‘furnished with a hook,’’ and refers to the hook or spur on the ventral edge of tergum IX.

DISTRIBUTION: Known only from northeastern Peru in Ucayali department (fig. 40).

Figures

Figs. 39–40. Oedichirus species. Distribution. 39. Mesoamerica and the Caribbean. 40. South America. (Species described prior to present work preceded with *. Symbols ³ or ♀ signify species known only by the sex indicated. Open circle denotes multiple collecting sites.)

Figs. 157–159. Oedichirus hamatus. 157. Segment IX, ventral, female. 158. Segment IX, left lateral, female. 159. Segment IX, vulvar plate, enlarged (CLSM).