Hexanchorus flintorum, Maier, Crystal A., 2013

Maier, Crystal A., 2013, A revision of the Larainae (Coleoptera, Elmidae) of Venezuela, with description of nine new species, ZooKeys 329, pp. 33-91 : 48-51

Hexanchorus flintorum sp. n. Figs 4, 32, 33, 34, 35, 36

Type material.

Holotype Male."VENEZUELA: Me. [ Mérida State]; Rio Montealban, Rt. 4; 19km W. Mérida; 20 Feb. 1976; C.M. & O.S. Flint, Jr." Holotype deposited in USNM. Paratypes (22): VENEZUELA: Mérida State: Same data as holotype (2 specimens USNM). "VENEZUELA: Mérida State; 8°35.355'N, 71°13.926'W, 1646m; N. of Ejido, Rt. 4 river x-ing; 10.vii.2009; leg. Shepard; gross sample; VZ09-0720-02Z" (20 specimens SEMC). Paratypes will be deposited in: 5 in USNM, 2 in MIZA, 1 in MALUZ, 14 in SEMC.

Diagnosis.

Hexanchorus flintorum can be distinguished from all other species of Hexanchorus that occur in Venezuela by the following combination of characters: pronotum without median longitudinal impression (Fig. 32), but with strong postero-median impression; parameres of male short, reaching less than half the length of the aedeagus (Fig. 36).

Description.

Holotype Male. Body elongate, subparallel, dorsum moderately convex. Length, 4.3 mm; greatest width, 1.5 mm. Body dark brown dorsally; venter dark brownish black (Fig. 32). Base of antenna, basal half of tibiae, and basal two thirds of femora light to medium brown (Fig. 33). Dorsal surface densely covered with short recumbent setae; ventral surface densely covered with short, recumbent setae and long, golden setae. Setae golden, and lacking greenish iridescence. Surface microreticulate, with dense fine punctures; fine punctures separated by distance equal to puncture diameter.

Head moderately coarsely, densely punctate; punctures separated by their diameter; cuticle microreticulate. Clypeus with anterior margin slightly concave; angle on each side acute. Labrum with anterior margin entire and gently concave; angle on each side acute, with row of dense, long golden setae. Eyes hemispherical, narrowed poste riorly and bordered by long black curved setae ( “eyelashes”) that arise near dorsal and ventral sides of eyes and extend toward middle of eye. Antenna pubescent, clubbed; basal antennomeres I and II medium to light brown, with long setae, longer than width of segments, and dense recumbent setae; antennal club very loose, just slightly thickened towards apex (Fig. 32). Antennae short, reaching transverse groove of pro notum (Fig. 33). Apical antennomeres dark brownish black, with dense recumbent setae. Apical antennomere rounded.

Pronotum 1.1 mm long, 1.0 mm wide; with weak sublateral groove; lateral margins slightly sinuate; anterolateral angles obtuse, slightly explanate; base of pronotum slightly sinuate and with broad lobe medially; posterolateral angles obtuse, slightly explanate, declivous, depressed adjacent to each angle (Fig. 33); discal area with fine, dense punctures, punctures separated by a distance equal to or less than their diameter; cuticle microreticulate. Pronotal disc with slight median longitudinal drepression, with strong postero-medial impression; disc covered with golden setae. Lateral projection of hypomeron very acute, nearly absent. Prosternum short in front of procoxae; with tuft of dense golden setae apicomedially (Fig. 33). Prosternal process triangular, broad at base and tapering to apex; disc slightly impressed, without V-shaped groove; lateral margins reflexed; middle moderately longitudinally cariniform; apex narrow, acute (Fig. 33). Scutellum slightly longer than broad; flat, not at all convex, not distinctly elevated above the adjacent elytral intervals. Mesoventrite short, depressed, with a deep, broad, V-shaped depression for reception of apex of prosternal process. Metaventrite with disc inflated on posterior three-fourths, finely punctate behind mesocoxae, punctures becoming more sparse laterally, with large, rounded depressions scattered on disc; with deep longitudinal groove on midline of disc, groove deeper and broader on posterior third of disc (Fig. 33); with short, dense, short pubescence; cuticular surface of metaventrite finely microreticulate.

Legs long and slender, dark brown (Fig. 33). Procoxae and metacoxae moderately widely separated; mesocoxae slightly more widely separated (Fig. 33). Protibia only with very slight excavation for reception of tarsi, lacking apical tooth. Protarsus of male not expanded apicomedially. Mesotibiae of male with medial pubescent area long; lateral pubescent area only at extreme base; with fine, short, nearly longitudinal carina on inner apex (Fig. 33). Tarsal claws long and stout, light brown. Metafemur of male with internal glabrous patch.

Elytron with ten rows of fine punctures; punctures separated by a distance three to four times the diameter of the puncture; intervals with fine, golden, dense pubescence; humeral area swollen (Fig. 32). Elytral striae obscured apically. Elytron widening to about posterior two-thirds before converging to acute apex. Apical third of elytron not inflated. Elytron without strong impression at basal third. Lateral bead of elytron slightly sinuate. Elytra 3.5 times as long as pronotum; broadest point across humeri. Inner side of apex straight (Fig. 32); lateral margins smooth; humeri gibbous; elytral intervals slightly elevated; punctures on intervals no larger than finest punctures of head and pronotum and separated by 2-5 times puncture diameter.

Abdomen with five ventrites (Fig. 33). First three ventrites broadly, shallowly depressed and distinctly carinate adjacent to metacoxae; carinae extending longitudinally behind metacoxae for almost entire length of first ventrite; cuticle densely covered with long, golden setae (Fig. 33). Last ventrite deeply and broadly emarginate. Aedeagus strongly curved toward apex; parameres short, reaching less than half the length of the aedeagus (Fig. 36).

Female. Externally similar to male except inner apex of each elytron expanded posteriorly and slightly turned upward (Fig. 35). Protibiae slightly less curved than those of male. Metaventral disc not as deeply and less extensively concave. Abdominal sterna 1-3 convex, not concave.

Intraspecific variation.

This species varies slightly in color, length (3.9-4.2 mm, and degree of setation.

Etymology.

This species is named in honor of Dr. Oliver S. Flint and Mrs. Carol M. Flint who collected the specimens.

Distribution and habitat.

This species is only known from the mountains to the West of the Rio Chama valley near Ejido and Mérida, Mérida State, Venezuela, specifically, at Rio Montealban (Fig. 4). The largest series was collected from stream margins and pools at a river crossing north of Ejido.

Associated species.

The laraine elmid species Disersus dasycolus and Pharceonus grandis were collected in the same samples as Hexanchorus flintorum . Other aquatic beetles collected at the same localities include: Andogyrus spp. ( Gyrinidae ).