Oedichirus optatus Sharp

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 : 107-112

Oedichirus optatus Sharp

Figures 40 , 188–196

Oedichirus optatus Sharp, 1876: 339 .

— Bernhauer and Schubert, 1912: 201 (catalog). — Blackwelder, 1944: 131 (checklist).

TYPE MATERIAL: Three syntypes: One male, two females, all from Tapajos. Sharp (1876: 339– 340) stated the species was represented by a male and two females, but did not designate a type. To stabilize the name a lectotype is designated.

LECTOTYPE: Designated here. Male. ‘‘Type/Tapajos/Sharp Coll. 1905-313/ Oedichirus optatus ³ Type D.S./ LECTOTYPE Oedichirus optatus Shp. des. L. Herman, 2011.’’ Deposited in the Museum of Natural History, London. (The specimen is mounted between two rectangles of clear plastic and glued to a transverse strip across the opening of a card with the center removed. The specimen was dissected by someone, perhaps Sharp, prior to my examination; segments IX/X and the aedeagus are glued to the left of the specimen and segment VIII to the right. The aedeagus is damaged; the basal half is collapsed and the apical third of the right paramere is missing. The right side of the pterothorax and right elytron has a pin hole. The specimen is pale reddish brown, not fully pigmented, and perhaps slightly teneral. For the present study, the lectotype was not removed from the card.)

PARALECTOTYPES: Two females. Paralectotype 1: Same labels in same order as lectotype; bottom label differs as: ‘‘ Oedichirus optatus ♀ Type D.S.’’ The specimen is undissected and mounted in the same manner as the lectotype. Paralectotype 2: ‘‘Cotype/Tapajos/Sharp Coll. 1905-313/ 187/ Oedichirus optatus Indtype D.S. ’’ The second paralectotype is mounted on a card, is not covered by plastic rectangles, and was not dissected. Both specimens bear my printed paralectotype label.

TYPE LOCALITY: Brazil: Pará: Tapajos (2 ° 269– 3 ° 439S, 54 ° 419–55 ° 249W). (See Localities below for a discussion of the type locality).

DIAGNOSIS: Externally Oedichirus optatus is separated from all other New World species by the presence of six labral denticles. However, since the second denticle, the one between the sublateral and submedial ones, is small to obsolete and might be overlooked, the character is marginally useful. The species is one of six (see also O. batillus , O. bicristatus , O. hamatus , O. isthmus , O. sinuosus ) with paratergite III. The males of O. optatus differ from the five aforementioned species and all others by the deep, narrow emargination of sternum VIII (fig. 193), the form of the aedeagus (figs. 188–191), and the long, broad, flattened parameres, each of which has a long slender process arising from near the middle of the ventral edge. Sternum VIII of the males has a broad depression adjacent to the median emargination and the depression has a patch of short, coarse setae anteriorly (fig. 193).

Uniquely among the females of the New World species, the median gonocoxal plate of O. optatus is strongly asymmetrical (fig. 195). The vulvar plate is embedded near the middle of the gonocoxal plate. The anterior vulvar lobe is covered with short, stout cuticular processes and embraces the anterior and lateral sides of the posterior lobe (fig. 196). The posterior vulvar lobe, with its form and cobbled surface, is strawberrylike (fig. 196). For tergum IX the right anteroventral angle extends across to meet the left side for which the anteroventral angle is absent (fig. 195). The posterior margin of sternum VIII of females has a broad, rounded, median lobe (fig. 192).

DESCRIPTION: Length: 8.0– 10.3 mm. Length of head: 0.8 mm. Width of head: 1.1–1.2 mm. Pronotal length: 1.4–1.5 mm. Pronotal width: 1.1–1.2 mm. Elytral length: 1.1–1.3 mm. Elytral width: 1.2–1.3 mm.

Body concolorous, pale reddish brown (teneral specimens) to dark reddish brown to black, some specimens with paler reddishbrown infusions. Legs reddish brown with slightly darker infusion at femorotibial joint in paler specimens; tibiae paler reddish brown, yellowish brown in more teneral specimens.

Head wider than long (HW/HL: 1.3–1.4). Frontoclypeal ridge incomplete, separated medially. Dorsal surface without V-shaped depression; surface coarsely and moderately densely punctate laterally to base and medially; basal region impunctate medially. Labrum with six denticles; second pair smaller than sublateral or submedial pairs and obsolete in some specimens, particularly females; surface without tubercle near submedial denticle.

Pronotum longer than wide (PL/PW: 1.2– 1.3). Pronotum polished and with coarse, moderately dense punctation; surface with prominent, coarsely punctate, submedial groove on basal half. Elytra with length equal to width to about one tenth shorter than wide (EW/EL: 1.0–1.1); surface flat to slightly convex and coarsely punctate.

Abdomen irregularly and densely punctate; punctures not arranged in rows on most of surface. Segment III with long, narrow, triangular paratergite extending entire length of segment. Tergum III without median point extending from transverse basal ridge. Tergum VIII with posterior margin truncate to broadly and shallowly rounded; transverse basal ridge irregularly sinuate, slightly curved anteriorly, and without median point. Tergum IX with lateroapical process about one tenth to a third longer than midbasal length (LLaP/L9 5 1.1–1.3), slightly bent ventrally, and approximately parallel to other process; ventromedial margin without posteriorly directed spur (cf. fig. 158).

MALE: Sternum VI unmodified. Sternum VII with slight, shallow, elliptical, median depression near posterior margin. Sternum VIII (fig. 193) with symmetrical, narrow, deep emargination of posterior margin; emargination more than a third to two fifths as long as segment and deeper than wide, base narrowly rounded, margins of apical third slightly less convergent than more strongly convergent basal two thirds; margins of emargination beveled; posterior margin without membranous marginal strip; surface with deep, oval depression laterad of basal half of emargination; depression deep basally and gradually shallower apically; depression without punctation or pubescence, but surface with cluster of setae adjacent to medial and basal margins of depression; surface without comb of setae; transverse basal ridge broadly and shallowly sinuate and irregularly submacrosinuate. Tergum IX with large process extending from anterior margin of anteroventral angle. Sternum IX (fig. 194) slightly asymmetrical; anterior margin moderately wide and strongly rounded; posterior margin nearly trunctate; lateral margins rounded.

Aedeagus asymmetrical (figs. 188–191). Ventral sclerite with small tumescence to left of midsagittal line and proximad of posterior margin, with shallow depression on right side of tumescence, and without apicoventral process or other prominent lobes or processes. Parameres long, flattened, prominent, and tapered apically; basal third or half fused to median lobe almost indistinguishable (figs. 188, 190); apical half to two thirds free of median lobe and extending far beyond posterior margin of median lobe; parameres each with long, slender process extending posteriorly from about middle of ventral edge (figs. 188, 190); right paramere moderately longer than left; parameres asymmetrical and of differing form. Internal sac with one spinelike process and long, slender, subapically bent and sinuate process (figs. 189–191).

FEMALE: Sternum VIII with broad, round- ed lobe on posterior margin (fig. 192). Tergum IX (fig. 195) with anteroventral angles strongly asymmetrical and touching, but not fused; angle of right side broad, long, apically hooked, and extending across width of segment to meet angle of left side of segment; carina present on right angle near right lateral margin; angle of left side absent and not extending toward middle; left ventromedial margin of tergum IX with large lobe proximad of middle and extending toward vulvar plate. Median gonocoxal plate strongly asymmetrical (fig. 195); gonocoxal plate anteriad of vulvar plate nearly as large as gonocoxal plate posteriad of vulvar plate; anterior margin of gonocoxal plate broadly rounded and at diagonal to midsagittal line; left margin strongly rounded and lobiform; gonocoxal plate posteriad of vulvar plate with gradually tapered to slightly rounded posteri- or margin. Vulvar plate (fig. 196) embedded in gonocoxal plate near middle. Anterior vulvar lobe narrow and embracing anterior margin and about half of lateral margin of posterior vulvar lobe; surface with short, stout cuticular processes. Posterior vulvar lobe large, round- ed, ‘‘strawberrylike,’’ and covered with cobble. Vulva diagonally oriented.

MATERIAL EXAMINED: Ten males, 4 females, 1 damaged specimen of unknown sex. Brazil: Pará: Tapajos (1 male lectotype, 2 females paralectotypes, BMNH) ; Pará: Caninde, Rio Gurupi (2 ° 349S, 46 ° 319W), IV/7– 15/1963, leg. B. Malkin, forest sweep (1 male, FMNH), II/27–28/1966, leg. B. Malkin (1 male, FMNH) ; Pará: Fazenda Pirelli (01 ° 259S, 48 ° 189W; coordinate courtesy of A. Asenjo), Belem, III-30–31-1970, J.M. Campbell & B.A. Campbell (1 male, 1 female, CNC). Maranhão (not Pará): Aldeia Aracu, Igarape, Gurupu-Umu, Maranhao, 50 km E of Caninde (2 ° 349S, 46 ° 029W), leg. B. Malkin, forest sweep, V-1963 (2 males, FMNH). Mato Grosso: Barra do Tapirape , 17/I–2/II/1964, FMHD # 64-3002, sweeping forest, night, B. Malkin (1 male, FMNH), I/ 4–11, 1963, FMHD # 63-3001, beating rain forest at night, B. Malkin (1 specimen (apical segments of abdomen missing), FMNH) ; Mato Grosso: Barrado [sic] Tapirape, XII/ 25/62, leg. B. Malkin (2 males, FMNH) ; Mato Grosso: Tapirape Indian village at confluence of R. Tapirape and R. Araguaia (10 ° 289S, 50 ° 259W), Nov. 11–20, 1960, leg. B. Malkin (1 male [head and prothorax missing], 1 female, FMNH), Dec. 26–31, 1960 (1 female, FMNH) .

LOCALITIES: The syntypes of O. optatus were collected by H.W. Bates from Tapajós, a river the mouth of which is near Santarém, Pará at about 2 ° 269S, 54 ° 419W (from Google Earth). Bates headquartered at Santarém for three and a half years. After living there for six months he left on June 8, 1852, on a fourmonth expedition up Rio Tapajós to Rio Cupari (at about 3 ° 439S, 55 ° 249W) (from Google Earth), where he then travelled 30 to 40 miles upriver to a village of the Mundurucus ( Bates, 1863: 71–152). Since the locality label gives no further information than ‘‘Tapajos’’ O. optatus could have been collected anywhere along the river, but perhaps not near a town or village since Bates includes no such information on the label, so herein the coordinates for ‘‘Tapajós’’ bracket his journey up the river (2 ° 269–3 ° 439S, 54 ° 419– 55 ° 249W) to the mouth of the Cupari.

Other specimens were collected from Caninde near Rio Gurupi and from 50 km east of Caninde. The specimens were collected at both sites by the same person only two weeks apart, and one of the samples includes the name of the river. Although the locality label for specimens collected 50 km east of Caninde reads as though they were collected in Pará, Rio Gurupi is the border between Pará and Maranhão, so east of the river is in the latter state and that name is included on the label. The label for the specimen of O. optatus collected 50 km east of Caninde does not include Rio Gurupi, but Oliveira (2006: 123) reported a euglossine bee, Eulaema pseudocingulata Oliviera , collected by the same collector, Borys Malkin, with the label data: ‘‘Aldeia Yararuhu (Aracu), Igarape Gurupi-Una, Rio Gurupi.’’ However, the locality information as published for the bee is incomplete. The specimens on which Oliveira’s citation is based are deposited in the American Museum and the locality label also includes ‘‘ Maranhao, about 50 km E Caninde,’’ so despite the differences in the label for the paederine and the published data for the euglossine, the specimens were collected at the same locality. Caninde near Rio Gurupi is at 2 ° 349S, 46 ° 319W and 50 km east (by air) of Caninde is at about 2 ° 349S, 46 ° 029W; the latter site is in Maranhão state, not Pará.

All of the collecting sites in Mato Grosso are associated with Rio Tapirape. One site, a Tapirape Indian village at the confluence of Rio Tapirape and Rio Araguaia, is at 10 ° 289S, 50 ° 259W. Santa Terezinha is now near the confluence (coordinates from Google Earth). The other locality records from Mato Grosso, ‘‘Barra do’’ or ‘‘Barrado’’ Tapirape, were not found.

DISTRIBUTION: Known only from Brazil, Oedichirus optatus has been collected near three rivers in two states, Rio Tapirape in Mato Grosso, Rio Tapajós and Rio Gurupi in Pará, and it has been collected in Maranhão state (fig. 40).

BIONOMICS: Oedichirus optatus was collected by H.W. Bates on ‘‘trees’’ ( Sharp, 1876: 338). Most of the specimens collected by Borys Malkin were taken by ‘‘sweeping the forest’’ vegetation. Specimens were collected from November to February, and March, April, and May.

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. 188–195. Oedichirus optatus. 188. Aedeagus, right lateral. 189. Aedeagus, ventral. 190. Aedeagus, left lateral. 191. Aedeagus, dorsal. 192. Tergum VIII, apical margin, female. 193. Sternum VIII, setae removed except those near depression, male. 194. Sternum IX, male. 195. Segment IX, ventral, female.

Fig. 196. Oedichirus optatus. Segment IX, vulvar plate, enlarged (CLSM).