Chiasmognathus scythicus Engel & Packer, 2013

Engel, Michael S. & Packer, Laurence, 2013, A new species of Chiasmognathus from Kazakhstan (Hymenoptera: Apidae), Journal of Melittology 2013 (10), pp. 1-7 : 2-7

Chiasmognathus scythicus Engel & Packer , new species

ZooBank urn:lsid:zoobank.org:act:F5C60D49-59D0-4772-A771-E77B712E8823

( Figs. 1–11 )

DIAGNOSIS: Superficially the new species resembles C. gussakovskii but differs most notably by the shape of the hidden metasomal sterna ( Figs. 4, 5 : cf. Popov, 1937): seventh metasomal sternum broader apically before process, giving disc a rectangular or trapezoidal shape (more strongly narrowed apically and thereby triangular in C. gussakovskii ), apical process glabrous (with short setae in C. gussakovskii ); eighth sternum with discs reduced laterally and deeply concave basolaterally (discs broad laterally in C. gussakovskii ), and lateral apodemes broad and rounded apically (narrowed with acutely rounded proximal angle and pointed apical angle in C. gussakovskii ). The dorsal division between the gonocoxae is much deeper (extending half the length of the gonocoxae) than in C. gussakovskii (approximately ¼ the length according to Popov, 1937: fig. 2) resulting in more prominent dorsoapical lobes ( Fig. 8 ). The sterna more closely resemble the shape observed in C. orientanus ( Warncke, 1983) from Bulgaria, Crete, Cyprus, Turkey, and Israel (but likely spread throughout the Levant) (cf. Warncke, 1983), but differ in the shorter lateral apodemes of the eighth sternum, the disc more developed laterally, and more constricted apical process beyond the disc (broadly tapering from lateral apodemes to apical process in C. orientanus ).

DESCRIPTION: ♂: Total body length 2.42 mm (2.14–2.87 mm); forewing length 1.61 mm (1.38–2.03 mm). Head wider than long, width 0.86 mm (0.82–0.95 mm), length 0.70 mm (0.64–0.76 mm); inner margins of compound eyes straight, convergent below; apex of clypeus at lower tangent of compound eyes; ocelli above upper tangent of compound eyes, ocellar triangle prominent, slightly swollen above curvature of head, vertex weakly concave between lateral ocelli; clypeus weakly convex, nearly flat, apicolateral corners of clypeus with small patches of tightly packed, elongate, curved setae; malar space vestigial posteriorly, 0.7X diameter of median ocellus anteriorly; mandibles simple, crossing in repose but not covering labrum; frontal line distinct from just below lower tangent of antennal toruli to median ocellus, raised below, impressed above. Mesoscutum with median and parapsidal lines weakly impressed, median line extending to just before mesoscutal midlength. Intertegular distance (i.e., distance between inner margins of tegulae) 0.47 mm (0.43–0.60 mm). Forewing marginal cell broadly truncate; both m-cu crossveins entering second submarginal cell. Terminalia as depicted in figures 4–8.

Integument generally shining ( Figs. 1–3 ). Labrum with punctures irregular in size and spacing, surface smooth; clypeus with small punctures separated by 0.5–2 times a puncture width centrally, punctures closer laterally, with a few scattered larger punctures, apex impunctate; face and vertex with small punctures separated by 0.25–2 times a puncture width (in a few places where punctures are particularly close they can be nearly contiguous), integument between punctures smooth, punctures on vertex posterior to ocelli somewhat weaker; punctures on gena and postgena separated by 0.5–2 times a puncture width, integument otherwise smooth and shining. Mesoscutum sparsely punctate on central disc, punctures small and separated by 1–4.5 times a puncture width, punctures closer on margins, integument otherwise smooth and shining; mesoscutellum with punctures slightly larger and deeper than those of mesoscutum, separated by 0.5–2 times a puncture width; metanotum with punctures separated by a puncture width; pleura with small punctures separated by 0.5–2.5 times a puncture width, integument otherwise smooth; propodeum with short and narrow basal area coarsely imbricate and impunctate, otherwise integument with punctures separated by less than or equal to a puncture width except medially around pit on posterior surface smooth. Metasomal terga and sterna faintly and finely imbricate, with fine, scattered punctures (T1 and T2 almost devoid of sculpture in some specimens).

Integument of head and mesosoma black to dark brown and shining except yellowish to reddish brown on mandibles (which have reddish apices), yellowish to reddish brown on labrum, light brown to brown on labiomaxillary complex, light brown to yellow on scape and pedicel, light yellow brown on flagellum, translucent amber on tegula, and light brown on legs except lighter on tarsi and at femorotibial and tibiobasitarsal joints. Wing veins amber except C and Sc+R darker; membranes hyaline. Metasoma dark chestnut brown; apical impressed areas lighter in color.

Pubescence silvery white. Head with numerous, fine, appressed to subappressed plumose setae, such setae nearly obscuring integument of face around and below level of antennal toruli, and intermingled with a few suberect to erect finer, simple setae; appressed plumose setae present on gena. Setae of mesosoma like those of head although more sparse centrally on mesoscutum and mesoscutellum; setae similar to those of gena on pleura (although longer and more diffuse to sparse centrally on mesepisternum), metanotum, and dorsolateral portions of propodeum, obscuring underlying integument especially on metanotum. Metasoma with sparse, erect to suberect, short simple setae, without prominent apical fasciae; first metasomal tergum with small, weak apicolateral patches of appressed to subappressed plumose setae (rubbed off in some specimens); succeeding terga with similar patches although often more diffuse or smaller than those of first tergum.

♀: As described for male except in usual gender differences ( Engel, 2006, 2009) and as follows: Total body length 2.13–2.77 mm; forewing length 1.60–2.00 mm. Head wider than long, width 0.79–0.99 mm, length 0.56–0.81 mm. Ocellar triangle not as prominent as in male. Intertegular distance 0.45–0.60 mm.

Sculpturing as in male except punctures of mesoscutellum closer, separated by 0.5–1.5 times a puncture width.

Coloration as in male except sometimes lighter brown throughout on those areas where male is black, especially face below antennae ( Figs. 9–11 ), and nearly black around ocellar triangle regardless of background color of integument (lighter colors likely due to fading of integument).

Pubescence more dense on clypeus and lower paraocular area.

HOLOTYPE: ♂, Kazakhstan: Almaty, Taūqum Sands, 20 km [North] of Aydarly, 550 m, 44.0343°N, 79.5184°E, 30.vii.1988 [30 July 1988], Kazenas ( KASC). The type locality is in southeastern Kazakhstan east of the Kapshagay Reservoir and around the Altyn Emel National Park , and generally part of the xeric to mountainous ecoregion of Kazakhstan.

PARATYPES: 1♂♂, 4♀♀, same data as holotype ( KASC except one female at each of KUEC and PCYU) ; 2♂♂, 1♀, same data as holotype except 24.vii.1988 [24 July 1998] (female at KASC one male each at of KUEC and PCYU) ; 1♂, Kazakhstan: Almaty, Ilie River, 30 km S [South-Southeast] of Koktal , 44.1339°N, 79.8064°E, 600 m, 6.vii.1993 [6 July 1993], Kazenas ( KASC) ; 1♂, 1♀, Kazakhstan: Almaty, 30 km [East] of Chilik, Borandrusy , 43.5474°N, 78.0766°E, 13.vi.1997 [13 June 1997], Kazenas ( SEMC) . The type series is in less than desirable condition, with many of the specimens poorly mounted, glued to cards so that various portions are embedded and obscured (and the glue has deteriorated into a crystalline matrix rendering it virtually impossible to separate specimens). One male collected 24 July (in KASC) has been decapitated.

VARIATION: There is variation in metasomal coloration among the available specimens. For example, in some males the first and other terga are lighter in their apical two-thirds, resulting in a somewhat banded appearance. Females seem to vary in the degree to which the first tergum is red and the degree to which it is differentiated in color from the succeeding terga. The degree to which pubescence is developed on the metasoma is variable (perhaps due to the degree to which individuals are worn), with patches of appressed to subappressed plumose setae apicolaterally on the terga somewhat larger and more dense in some individuals. As noted above, there is variation in the degree of sculpture on T1 and T2.

ETYMOLOGY: The specific epithet is a reference to the ancient region of Scythia (8th Century BC to 2nd Century AD), which encompassed much of modern-day Kazakhstan (particularly the Kazakh steppe and Saka tigrakhaude) as well as bordering regions in Central Asia (Sakastan, Ponto-Caspian steppe) and easternmost Europe (Sarmatia, Scythia Minor).

Figures

Figures 1–3. Photomicrographs of male of Chiasmognathus scythicus, new species. 1. Lateral habitus. 2. Dorsal habitus. 3. Facial view.

Figures 4–8. Male terminalia of Chiasmognathus scythicus, new species. 4. Seventh metasomal sternum. 5. Eighth metasomal sternum. 6. Genital capsule, ventral view. 7. Genital capsule, lateral view. 8. Genital capsule, dorsal view.

Figures 9–11. Photomicrographs of female of Chiasmognathus scythicus, new species. 9. Lateral habitus. 10. Dorsal habitus. 11. Facial view.