Oedichirus lunatus, 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 : 94-97

Oedichirus lunatus , new species

Figures 40 , 166–171

TYPE MATERIAL: Holotype: Female. ‘‘ BRAZIL: Bahia:Itabuna: CEPLAC, 26-1-1995 NR 100m, F95301 W1 14 ° 389S 39 ° 189W D. Agosti, abandoned cocoa plantation/ Holotype Oedichirus lunatus Herman. ’’ Deposited in the American Museum of Natural History.

PARATYPE: One female. Same data as holotype ( AMNH)

TYPE LOCALITY: Brazil: Bahia: Itabuna, CEPLAC, 14 ° 389S 39 ° 189W, 100 m. (The species was collected at a facility of the Comissão Executiva do Plano da Lavoura Cacaueira [CEPLAC].)

DIAGNOSIS: The long, ventrally strongly bent, lateroapical process of tergum IX (fig. 168) will separate the species from all known New World species all of which have a slightly to moderately curved process (fig. 158). The lateroapical process of tergum IX is about five times longer than the midbasal length of the tergum and is longer than that of any other New World species. Oedichirus lunatus is the only New World species for which the pronotal length and width are about equal; for all others the pronotal length is greater than the width. Among the New World species only O. echinatus , O. lunatus , and O. procerus have a bidentate labrum; the preceding characters will permit separation. The male is unknown.

DESCRIPTION: Length: 4.2–4.7 mm. Length of head: 0.5 mm. Width of head: 0.6 mm. Pronotal length: 0.7 mm. Pronotal width: 0.7 mm. Elytral length: 0.6 mm. Elytral width: 0.7 mm.

Body reddish brown. Head darker reddish brown than pronotum, elytra, or abdomen; pronotum paler than to concolorous with elytra and abdomen. Legs concolorous paler reddish brown to yellowish brown and without femorotibial maculation.

Head wider than long (HW/HL: 1.2). Frontoclypeal ridge absent. Dorsal surface without V-shaped depression; surface coarsely and densely punctate; punctation evenly distributed; surface polished between punctures except just proximad of frontoclypeus. Labrum bidentate; denticle small and adjacent to median emargination; surface without tubercle near denticle.

Pronotum with length nearly equal to or slightly less than width (PW/PW: 1.0). Pronotum polished, with coarse dense punctation and with medial and several sublateral impunctate spots; surface without submedial punctate groove. Elytra about a fifth wider than long (EW/EL: 1.2); surface moderately convex and coarsely punctate.

Abdominal terga III to V densely and coarsely punctate and punctures not arranged in rows; terga VI to VIII with less coarse, less dense punctation. Segment III without paratergite; paratergal carina present and extending for most of length of segment, nearly reaching posterior margin, and poorly developed beyond spiracle. Tergum III without median point extending from transverse basal ridge. Tergum VIII (fig. 166) with small median lobe on nearly truncate posterior margin; transverse basal ridge irregularly sinuate and with large median point; surface with broad, transverse depression. Tergum IX with lateroapical process five times longer than midbasal length (LLaP/T9 5 5.2), strongly bent ventrally (fig. 168), and, in dorsal view, processes nearer to one another near base and widely separated apically (fig. 170); ventromedial margin without posteriorly directed spur (cf. fig. 158).

FEMALE: Sterna III to VII unmodified. Sternum VIII (fig. 167) with posterior margin sinuate, broadly rounded medially; transverse basal ridge broadly sinuate and without median point. Tergum IX with anteroventral angles fused medially forming narrow strap (figs. 169, 171). Median gonocoxal plate anteriad of vulvar plate reduced to strap and apparently fused to anteroventral strap of tergum IX (figs. 169, 171); gonocoxal plate posteriad of vulvar plate with broadly rounded lateral margins tapering to broadly, feebly emarginate posterior margin (fig. 169). Anterior vulvar lobe (fig. 171) apparently narrow and transverse, but poorly discernible. Posterior vulvar lobe large (fig. 171); surface with network of filaments surrounding anterior to left lateroposterior margin of vulvar area and remainder of surface with cobble. Vulva of indeterminate orientation.

MALE: Unknown.

ETYMOLOGY: The name is from the Latin lunatus for ‘‘crescent-moon shaped’’ and refers to the nearly semicircular bend of the lateroapical processes of tergum IX.

DISTRIBUTION: Known only from Bahia province, Brazil (fig. 40).

REMARKS: This species, the smallest known from the New World, has a robust abdomen, the pronotal length is marginally shorter than the width, and the lateroapical processes of tergum IX are far longer than in other species and are so strongly bent that they nearly form a semicircle. The male is not known, but it is expected that the lateroapical processes of tergum IX would be similarly long and strongly curved. The lateroapical processes are narrowly separated prior to dissection and nearly touch each other for almost their entire length.

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. 166–170. Oedichirus lunatus. 166. Tergum VIII, female. 167. Sternum VIII, female. 168. Segment IX, left lateral, female. 169. Segment IX, ventral, female. 170. Terga IX and X, female.

Fig. 171. Oedichirus lunatus. Segment IX, vulvar plate, enlarged (CLSM).