Oedichirus sinuosus, 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 : 114-116

Oedichirus sinuosus , new species

Figures 39 , 199–205

TYPE MATERIAL: Holotype. Male. ‘‘ Mexico, Yucatán: Hoctun, August 12, 1973 J. Reddell/ Holotype Oedichirus sinuosus Herman. ’’ Deposited in the American Museum of Natural History. (Right antennomeres 7–11 are missing. Abdominal segments IV–VI are separted from the thorax and segment III and are glued to the point.)

TYPE LOCALITY: Mexico: Yucatán: Hoctun (20 ° 529N, 89 ° 129W). (In Yucatán two towns are named Hoctun. In correspondence J. Reddell, the collector of the species, wrote that the place at which he collected is 45–50 km SSE of Merida. The coordinates are from Google Earth.)

DIAGNOSIS: Oedichirus sinuosus is one of six New World species with paratergite III. The others are O. optatus , O. batillus , O.

bicristatus, O. isthmus , and O. hamatus . The legs of O. hamatus are bicolored, those of O. sinuosus are unicolorous. In contrast to O. sinuosus (fig. 203), sternum VIII of the males of O. batillus (fig. 53), O. bicristatus (fig. 59), and O. optatus (fig. 193) lack a transverse, subapical row of spinelike setae. The male of O. sinuosus has a curved, transverse, subapical row of spinelike setae on sternum VIII (fig. 203), whereas O. isthmus has a transverse, subapical cluster (fig. 163). The pronotal punctation of Oedichirus sinuosus is similar to that of O. boehmi in that both have few punctures and a well-defined submedial row, but the two are easily separated by the features cited in the preceding sentences.

DESCRIPTION: Length: 9.3 mm. Length of head: 0.9 mm. Width of head: 1.2 mm. Pronotal length: 1.4 mm. Pronotal width: 1.2 mm. Elytral length: 1.2 mm. Elytral width: 1.4 mm.

Body bicolored, reddish brown. Head dark reddish brown. Pronotum and elytra reddish brown, but elytra paler. Abdomen moderately dark reddish brown with paler infusions. Legs yellowish brown with feeble, pale reddish-brown infusions at femorotibial joints.

Head about one third wider than long (HW/HL: 1.3). Frontoclypeal ridge incomplete, separated medially. Dorsal surface without V-shaped depression; surface sparsely punctate, with a few punctures extending from frontoclypeal ridge to postocular lateral base and with small middorsal cluster; surface polished. Labrum quadridentate; surface without tubercle near submedial denticle.

Pronotum about one fifth longer than wide (PL/PW: 1.2). Pronotum polished; punctation sparse, coarse, and with lateral cluster and moderately deep, submedial, punctate groove extending most of length of pronotum. Elytra about one tenth wider than long (EW/EL: 1.1); surface slightly convex and coarsely punctate.

Abdominal segments III to VI coarsely punctate; punctation of III to V even basally and with irregularly arranged, poorly developed, subapical, transverse row of punctures; segments VI and VII with subbasal, subapical, and apical transverse rows of punctures dorsally, subbasal and subapical rows with punctures irregularly arranged; VII and VIII with finer punctation than on preceding segments. Segment III with paratergite; paratergal carina absent. Tergum III without median point extending from transverse basal ridge. Tergum VIII with posterior margin broadly emarginate; transverse basal ridge irregularly sinuate and shallowly curved anteriorly and without median point. Tergum IX with lateroapical process about one third longer than midbasal length of tergum (LLaP/L9 5 1.3), slightly bent ventrally, and approximately parallel to other process; ventromedial margin without posteriorly directed spur (cf. fig. 158).

MALE: Sternum VI unmodified. Sternum VII (fig. 205) with median, subapical cluster of slightly shorter, slightly stouter, recumbent setae. Sternum VIII (fig. 203) with broad, deep, asymmetrical emargination of posterior margin; emargination about one seventh of length of sternum, wider than deep, left side more strongly sloped than right, and margin broadly rounded basally and membranous; surface with comb of short, stout setae bordering emargination (fig. 203); comb extending medioanteriorly from near left lateral margin diagonally to just beyond midsagittal line; comb slightly sinuate on left side and strongly curved lateroposteriorly near middle of segment; right end of comb on low tumescence. Surface of sternum VIII with broad, moderately deep, polished, sparsely punctate, transverse depression between comb and transverse basal ridge; transverse basal ridge weakly sinuate, slightly curved anteriorly at middle, and without median point. Tergum IX with long, moderately wide process on anterior margin of anteroventral angle. Sternum IX (fig. 204) moderately asymmetrical; anterior margin wide and sinuate; posterior margin wide and broadly rounded; right lateral margin broadly round- ed posteriorly and sinuate anteriorly, left margin broadly and gently sinuate.

Aedeagus asymmetrical (fig. 199–201). Ventral sclerite with apical third long, slen- der, sinuate, tapered from broad base, compressed laterally, and narrowly rounded apically and in lateral view broad and thick basally, sinuate, tapered apically, and with rounded apex; ventral sclerite without apicoventral process extending to right from posterior margin. Parameres short, broad basally, strongly tapered and, from about middle, slender; parameres fused to median lobe basally, but mostly free of median lobe. Internal sac with with long, cylindrical, strongly sclerotized, apically blunt process (flagellum?) (fig. 202).

FEMALE: Unknown.

ETYMOLOGY: The name is from the Latin sinuosus , ‘‘sinuous,’’ and refers to the slender, sinuous apical third of the ventral sclerite of the aedeagus.

DISTRIBUTION: Known only from the Yucatán peninsula of Mexico (fig. 39).

REMARKS: The aedeagus of the holotype has a long, sclerotized, gradually tapered cylinder extending laterally and slightly anteriorly from the right side of the median lobe (figs. 199, 202). This process has a narrow central canal that opens at the distal end; it may be the flagellum.

The long sinuous apical portion of the ventral sclerite might be interpreted as an apicoventral process that is not curved. That view is not adopted since, herein, the apicoventral process is defined as curving to the right and extending from the lateroapical region of the posterior margin.

The species, collected in 1973 and identified by me in 1974, is the earliest known record for Oedichirus in Mexico.

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. 199–205. Oedichirus sinuosus. 199. Aedeagus, right lateral. 200. Aedeagus, ventral. 201. Aedeagus, left lateral. 202. Aedeagus, everted flagellum? of internal sac. 203. Sternum VIII, male. 204. Sternum IX, male. 205. Sternum VII, male (CLSM).