Oedichirus distortus, 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 : 70-73

Oedichirus distortus , new species

Figures 40 , 112–118

TYPE MATERIAL: Holotype. Male. ‘‘ Ecuador: Pastaza. Ashuara indian village on R. Macuma nr. R. Morona. VII:11–16:1971. B. Malkin./ night sweeping along forest trail/ Holotype Oedichirus distortus Herman. ’’ Deposited in the Field Museum of Natural History.

PARATYPES: One male, two females: Same data as holotype (2 females, FMNH, AMNH) ; Ecuador: Napo, Campana Cocha, E. pto. Misahualli , 2.VI.1982, H.Frania, 1100 ft., palm leaf litter (1 male, CNC). (See Localities below.)

TYPE LOCALITY: Ecuador: Pastaza: Ashuara indian village on Rio Macuma near Rio Morona. (This locality was not found and neither river seems to be in Pastaza province. Using the 1:1,000,000 maps for Ecuador from the American Geographical Society for Hispanic America both rivers were found in Morona Santiago province, but do not seem to be near each other.)

DIAGNOSIS: The unique form of sternum VIII and its long, sinuate, subapical combs (fig. 114) and the form of the aedeagus (fig. 113) will separate the males of O. distortus from all others in the New World.

Among the New World females of Oedichirus , the anteroventral angles of tergum IX are fused in O. dilophus , O. distortus , O. lunatus , O. ohausi , and O. procerus . Tergum VIII of only O. distortus has a median lobe, although small, on the posterior margin and the legs of O. distortus are bicolored, but are unicolorous for the other four species. The median gonocoxal plate is present anteriad of the vulvar plate for O. distortus (figs. 116, 118), O. lunatus (fig. 171), O. ohausi (fig. 186), and O. procerus (fig. 197), but absent for O. dilophus (fig. 108). For O. ohausi the median gonocoxal plate anteriad of the vulvar plate is fused to the transverse anteroventral strap of tergum IX (figs. 186, 187), but both sclerites are separate for O. distortus (figs. 116, 118). The adornment of the vulvar plate differs for each of the five species (cf. fig. 118 to figs. 110, 171, 187, 198).

DESCRIPTION: Length: 8.2–9.8 mm. Length of head: 0.9–1.1 mm. Width of head: 1.0– 1.1 mm. Pronotal length: 1.3–1.4 mm. Pronotal width: 1.1–1.2 mm. Elytral length: 1.1–1.2 mm. Elytral width: 1.2–1.3 mm.

Body bicolored. Head and pronotum black; elytra reddish brown; abdominal segments III to V reddish brown with darker infusions basally; segments VI to VIII dark reddish brown with paler reddish-brown infusions. Legs bicolored, pale reddish brown to yellowish brown with dark reddish brown femorotibial spot.

Head with length and width equal to or about a fifth wider than long (HW/HL: 1.0–1.2). Frontoclypeal ridge complete, not separated medially. Dorsal surface without V-shaped depression; surface polished and coarsely punctate; punctation dense, less dense basally and laterally. Labrum quadridentate; surface without tubercle near submedial denticle.

Pronotum about a fifth longer than wide (PL/PW: 1.2). Pronotum polished, with scattered clusters of moderately dense to dense, coarse punctation; surface with moderately deep, submedial, punctate groove on basal two thirds. Elytra length about a tenth less than width (EW/EL: 1.1); surface flat and coarsely punctate.

Abdominal segments III to VI coarsely punctate, VII and VIII less coarsely punctate; III to VI with transverse, subapical row of irregularly arranged punctures. Segment III without paratergite; paratergal carina extending to near middle of segment, but poorly developed beyond spiracle. Tergum III without median point extending from transverse basal ridge. Tergum VIII with small, median, trianguloid lobe on posterior margin; posterior margin broadly emarginate; transverse basal ridge irregularly sinuate and without median point. Tergum IX with lateroapical process about twice as long as midbasal length (LLaP/L9 5 1.9–2.0), slightly to moderately bent ventrally, and approximately parallel to other process; ventromedial margin without posteriorly directed spur (cf. fig. 158).

MALE: Sterna VI and VII unmodified. Sternum VIII (figs. 114, 115) with moderately deep, asymmetrical emargination; emargination about one sixth of length of sternum, wider than deep, with wide and broadly rounded base, with right margin longer and steeper than left, and with basal margin and part of lateral margins membranous; surface adjacent to emargination with transverse comb of long, spiniform setae (fig. 114); comb curved anteriorly on left side and posteriorly on right; surface of sternum with anteriorly curved ridge at base of comb on left side and with posteriorly curved ridge at base of comb on right side (fig. 115); surface tumescent at proximal base of both left and right curves of transverse ridge (fig. 115); transverse basal ridge broadly sinuate, separated medially, and with weak, apically open, median point (fig. 114). Tergum IX with small, lobed process on anterior margin of anteroventral angle. Sternum IX strongly asymmetrial (fig. 117); anterior margin wide and broadly emarginate; posterior margin narrow, rounded, and bluntly pointed; lateral margin tapered apically to pointed apex; right margin broadly rounded on basal third, then strongly sinuate to apex, left margin strongly sinuate to apex.

Aedeagus asymmetrical (figs. 112, 113). Ventral sclerite with short, broad, apically acute lobe on right side of apex and long, basally broad, tapering, apically acute lobe on right side of apex (fig. 113); left lobe much longer than right (fig. 113), with diagonally transverse, membranous depression extending from left basal margin of left lobe to near right lateral margin (fig. 113), with robust, small tumescence near base of right lobe at right lateral margin, with small, tapered, apically rounded lobe on left side just distad of middle (fig. 113), and without apicoventral process (cf. fig. 99) extending from posterior margin. Parameres short, slender, tapered, sinuate, and free of median lobe except at base (figs. 112, 113).

FEMALE: Sternum VIII with transverse basal ridge broadly sinuate and curved anteriorly at middle and without median point; posterior margin with wide, slight, microserrate, median emargination. Tergum IX with anteroventral angles fused medially to form wide strap (figs. 116, 118); strap with shallow groove at point of fusion. Median gonocoxal plate anteriad of vulvar plate reduced to narrow strap (figs. 116, 118) with anterior margin broadly rounded with small median lobe; gonocoxal plate posteriad of vulvar plate gradually tapered to irregularly microsinuate posterior margin (fig. 116). Vulvar plate embedded midanteriorly in gonocoxal plate (fig. 116). Anterior vulvar lobe transverse and extending across anterior margin of posterior vulvar lobe; surface slightly wrinkled (fig. 118). Posterior vulvar lobe transverse, larger than anterior lobe; surface with ornamentation near right lateral side. Vulva crescent shaped and orientated at slight angle to longitudinal axis (fig. 118).

ETYMOLOGY: The name is from the Latin distortus , ‘‘distorted or misshapened,’’ and refers to the strongly asymmetrical posterior margin of sternum VIII of the male.

LOCALITIES: Puerto Misahualli, Ecuador, is at the mouth of Río Misahualli at 431 m elevation at 01 ° 029S, 77 ° 409W ( Paynter, 1993: 128). The actual locality is Campana Cocha, east of Puerto Misahualli; that site was not found, but is presumably on the east side of Río Misahualli.

DISTRIBUTION: Ecuador in Napo and Pastaza provinces (fig. 40).

REMARKS: The two female paratypes were collected together with the holotype male and all three have dense coarse pronotal punctation, lateroapical processes of tergum IX that are about twice as long as the midbasal length of the tergum, and a small, triangular, median lobe on the broadly emarginate posterior margin of tergum VIII. The triangular lobe is more poorly developed on the male paratype from Puerto Misahualli and the pronotal punctation is more dense.

This species is the first record of the genus from Ecuador.

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. 112–117. Oedichirus distortus. 112. Aedeagus, right lateral. 113. Aedeagus, ventral. 114. Sternum VIII, male. 115. Sternum VIII, setae removed, male. 116. Segment IX, ventral, female. 117. Sternum IX, male.

Fig. 118. Oedichirus distortus. Segment IX, vulvar plate, enlarged (CLSM).