Ochthebius ustaoglui, Topkara, Tarik, Jäch, Manfred & Lu, Ahmet Kasapo Ğ, 2011

Topkara, Tarik, Jäch, Manfred & Lu, Ahmet Kasapo Ğ, 2011, Ochthebius ustaoglui sp. nov. (Coleoptera: Hydraenidae), a new species of the O. metallescens group from Turkey, Zootaxa 2913, pp. 59-62 : 59-60

Ochthebius ustaoglui sp. nov.

Type locality: Small stream, ca. 50 cm wide, 40°35'09''N 40°51'47''E, ca. 2200 m a.s.l., Ovit Pass, ca. 30 km NNW İspir, Erzurum, northeastern Turkey.

Material examined. Holotype male ( NMW): “ TR: ERZURUM Ovit Pass \ leg. Kasapoğlu 0 3. VII. 2000 ”. Paratypes: 5 males, 6 females ( ESFM, NMW): “ TURKEY: Prov. Denizli ca. 30 km SW of Beyağaç Lake Kartal, 1903 m a.s.l. 16.VII.2010 leg. E.T. Topkara”.

Description. 1.75–2.10 mm long. Black, legs sometimes slightly paler dark brown. Anterior corners of pronotum acute, postocular excision and postocular tooth usually well developed; lateral margins of pronotal ears straight, slightly convergent anteriad. Metaventrite posteromedially glabrous.

Sexual dimophism: Weakly pronounced. Explanate margin of elytra of females very slightly wider than in males, tips of elytra hardly noticeably more acuminate and more conjointly rounded. The shapes of labrum and protarsi are similar in both sexes. Posterior margin of terminal abdominal tergite of females with blunt spines.

Variability. Postocular emargination of pronotum and postocular tooth weakly or well developed. Pronotal disc moderately to densely punctate, glabrous. Length/width ratio of main part of aedeagal distal lobe varies considerably, from 1.73 to 2.16 (holotype: 1.86).

Differential diagnosis. Due to the high variability, we have not been able to detect significant external characters to distinguish the new species from Ochthebius hofratvukovitsi . The new species is, however, sufficiently characterized by its unusual aedeagus morphology.

Aedeagus ( Fig. 1 ): Main piece ca. 320–360 µm long, almost evenly curved (lateral view), slightly attenuate near middle, apex obliquely truncate. Distal lobe very conspicuously shaped: main part moderately wide, subcylindrical, subrectangular, about twice as long as wide, baso-ventrally and apically widely rounded; ventral margin at about apical third with a somewhat ax blade-shaped appendage, more or less compressed laterally, its distal apex widely rounded, basal apex acuminate and directed towards tip of main piece. Parameres more or less symmetrical, right one slightly longer than left one, close to main piece, inserted ventrally near basal 0.3 of main piece; apices with a few short setae.

Discussion. Despite the considerable linear distance between the two populations of about 1000 km, we could not detect significant aedeagal differences. However, examination of more material and molecular data will be necessary to bring forth conclusive evidence that the populations from Denizli and Erzurum really belong to a single species.

Based on external similarities, the new species is obviously related to Ochthebius hofratvukovitsi , O. khuzestanicus Ferro, 1982 and O. puberulus Reitter, 1885 (see Jäch 1989, 1994). No other species of this genus has an ax blade-shaped aedeagal apex. Externally, O. khuzestanicus deviates from the other three species in the presence of distinct elytral granules. Due to aedeagal similarities, Ochthebius serpentinus Jäch, 1989 might also belong to this cluster of species. However, its elytra are usually more ovoid and more glabrous.

Habitat notes. The holotype was collected from a small stream with cold and clear water, whereas the paratypes were sampled in small ponds, formed by melting snow near a lake shore. However, near the type locality there also were some small pools, which may in fact represent the original habitat of the population. Further field work will be necessary to reveal the habitat preferences of Ochthebius ustaoglui (see fig. 2).

Etymology. The new species is named in honour of Prof. Dr. M. Ruşen Ustaoğlu (Ege University, Faculty of Fisheries).

Distribution. The new species is only known from southwestern Turkey (Denizli, 37º05'46"N 28º51'02"E) and northeastern Turkey (Erzurum, 40°35'09''N 40°51'47''E) (see fig. 3).

Figures

FIGURE 1. Ochthebius ustaoglui sp. nov., lateral view of the aedeagus, paratype (from Kartal Lake).