Lacon kabakovi, Prosvirov, Alexander S., 2016

Prosvirov, Alexander S., 2016, New and little-known species of the genus Lacon Laporte, 1838 (Coleoptera: Elateridae) of Afghanistan and adjacent countries, Zootaxa 4168 (2), pp. 279-296 : 284-287

Lacon kabakovi sp. nov.

( Figs. 12, 15 , 18, 21 )

Type locality. Afghanistan, Nuristan Province.

Type material. Holotype, female, Afghanistan: “Afghan., Nurestan, SW Čapa-Dara, 2000 m, 11.6.1971, Kabakov ” [E Afghanistan, Nuristan Province, SW Chapa Dara District of Kunar Province, 2000 m, 11 June 1971, O.N. Kabakov leg.] ( ZISP, OK).

Diagnosis. L. kabakovi sp. nov. is closely related to L. diqingensis Prosvirov, 2016 ( Figs. 13, 16 , 19, 22 ). It can be distinguished from this species by the smaller body (body lengths are 12.70 mm and 13.20 mm, respectively), shinier integument, narrower pronotum, more elongate elytra, tongue-shaped scutellum, absence of wings, and different shape of genitalia.

Description. Female: Length 12.70 mm; width 3.90 mm. Body rather flattened, rather broad, oblong. Weakly shining, almost matt, all body dark reddish brown; elytra partially lighter; anterior margin of head, anterior margin and base of pronotum, beaded part of prosternal lobe, scutellum along margin, and basal margin of elytra darkened; maxillary palpi light brown. Body covered with golden, rather dense and short, recumbent scale-like setae; pubescence on dorsum and on prosternum distinctly longer than on other parts of body.

Head. Clearly wider than long (length/width 0.74); frons moderately deeply depressed almost over entire width; this depression extended to middle of vertex, being, however, shallow and obsolete medially. Punctures coarse and dense; intervals between punctures smaller than diameter of one puncture. Antennae reaching slightly beyond middle of pronotum, weakly serrate from antennomere 4. Antennomere 1 long, dilated; antennomere 2 almost globose, 0.8 times as long as antennomere 3; antennomere 4 1.4 times as long as antennomere 3; antennomeres 5 to 10 subequal in length, about 0.9 times as long as antennomere 4; last antennomere ovate, subapically slightly tapered (ratio of length/width of antennomeres from 1 to 5 as 2.2; 1; 1.25; 1.4; 1.2, respectively). Pubescence of antennae rather dense, setae slenderer and shorter than on other dorsal surfaces; recumbent setae interspersed with some erect ones. Mandible with tooth; apical segment of maxillary palpus noticeably broadened at apex, almost obtriangular.

Thorax. Pronotum more than 2.5 times as wide as head, slightly longer than wide (length 3.70 mm; width 3.65 mm), widest near middle, narrowed toward front angles more sharply than toward hind angles, sinuate before hind angles; weakly convex, flattened laterally. Front pronotal angles rather short, narrowly rounded, covering almost half eye length. Median impression on pronotal disc very shallow, apparent only in basal 1/3 of pronotum. Hind angles of pronotum depressed, rather short, rounded at apex, directed backwards and weakly divergent, without carina. Punctures coarse, very dense; intervals between punctures mostly smaller than half as great as diameter of one puncture; punctures on average larger than on head.

Prosternal sutures deeply grooved over half of their length, then simply furrowed. Prosternal lobe broadly rounded, rather short, almost completely covering labium, laterally separated from rest of prosternum by obsolete transverse impression at about anterior 1/4 of prosternum, with distinctly carinate anterior margin. Prosternal punctures coarse, dense, at basal 2/3 of prosternum distinctly larger than on pronotum; intervals between punctures smaller than half as great as diameter of one puncture; in anterior 1/3 of prosternum punctures distinctly smaller, intervals between punctures equal to or smaller than half as great as diameter of one puncture. Anterior and lateral parts of hypomeron with dense punctation, intervals between punctures on average smaller than diameter of one puncture; basal half of hypomeron near prosternal suture with larger and sparser punctuation, intervals between punctures on average subequal to or greater than diameter of one puncture; intervals between punctures on hypomeron matt. Hypomeron basally with rather broad and deep depression for insertion of profemora; this depression impunctate; hypomeron slightly impressed along prosternal suture in basal 1/2.

Prosternal process with weak prominence near apex, about 3 times as long as diameter of procoxal cavity, slightly bent inwards immediately behind procoxal cavities. Mesoventrite and metavenrite punctate similarly, intervals between punctures distinctly smaller than half as great as diameter of one puncture, punctures subequal in size to those on basal half of hypomeron. Metaventrite as long as wide, without depressions. Metepisternum rather slender, almost parallel-sided. Broad part of metacoxal plates about 4 times as wide as narrow part.

Scutellum short, tongue-shaped, anterior margin weakly emarginate medially, very weakly convex, with punctation as on elytra. Elytra oblong, slightly wider than pronotum, widest near middle, more than twice as long as pronotum (both elytra together: length: 8.05 mm; width: 3.90 mm); very slightly widened from anterior 1/4 to middle, then almost parallel-sided until about posterior 1/3, in posterior 1/3 tapering more strongly to apex than to base; shoulders obtusely rounded. Disc of elytra flat, weakly convex lateral to scutellum; elytra slightly sloping at posterior 1/3; elytra flattened along external margin, slightly divergent along suture near apex, blunted at apex; without striae, more or less evenly punctate; punctures subequal in size to those on head or smaller, rather sparse, intervals between punctures subequal to 1–4 diameters of one puncture.

Metathoracic wings absent.

Abdomen. Punctation of abdomen rather sparse, intervals between punctures subequal to or smaller than diameter of one puncture; punctures smaller than on metaventrite.

Female genitalia ( Figs. 18, 21 ). Ovipositor relatively long; baculum long, strongly sclerotized (ratio length baculum/length ovipositor 0.79); coxite moderately sclerotized, with several setae, narrowed to apex, with very small, almost indistinct stylus. Bursa copulatrix with large sclerotized plate typical of this genus covered with short spinules and long spines, distally with small sclerotized plate with short spinules; dark sac-like spermatophore contained inside bursa copulatrix.

Male. Unknown.

Larva. Unknown.

Distribution. Eastern Afghanistan: Nuristan Province, the Hindu Kush mountain system.

Bionomics. L. kabakovi sp. nov. was collected at a medium elevation; this wingless species probably inhabits only mountain areas. Other aspects of its biology remain unknown.

Etymology. Named in the honour of its collector, the distinguished geologist and entomologist Oleg N. Kabakov.

Systematic remarks. This species is also rather similar to L. lijiangensis Prosvirov, 2016 ( Figs. 14, 17 , 20, 23 ). All these species are characterized by the flattened and rather broad body and partial or complete reduction of the wings, apparently due to living in mountain regions. The genitalia of these species are also quite similar. It is very likely that all these species form a separate natural species group within the genus. The discovery of L. kabakovi sp. nov., which occurs in the Hindu Kush mountains, and the presence of other species of this group in the Hengduan Mountains ( China, Northwestern Yunnan) indicate that this group of the genus Lacon is probably widely distributed in the different mountain systems of the Himalayan region and the Tibetan Plateau.

Figures

FIGURES 12 – 17. Habitus of Lacon species, dorsal (Figs. 12 – 14) and lateral (Figs. 15 – 17) view. 12, 15. L. kabakovi sp. nov., female, holotype (12.7 mm). 13, 16. L. diqingensis, female, holotype (13.2 mm; China, Yunnan). 14, 17. L. lijiangensis, female, holotype (9.5 mm; China, Yunnan). Not to scale.

FIGURES 18 – 23. Genitalia of Lacon species: ovipositor, ventral view (Figs. 18 – 20); part of female genital tract, general view (Figs. 21 – 23). 18, 21. L. kabakovi sp. nov., female, holotype. 19, 22. L. diqingensis, female, holotype (China, Yunnan). 20, 23. L. lijiangensis, female, holotype (China, Yunnan). Not to scale.