Helius (Helius) oosterbroeki, Kopeć, Kania & Krzemiński, 2016

Kopeć, Katarzyna, Kania, Iwona & Krzemiński, Wiesław, 2016, New and little known crane-fly species of the genera Helius, Elephantomyia and Toxorhina (Diptera, Limoniidae) from Dominican and Mexican amber, Palaeontologia Electronica 13 (8), pp. 1-14 : 5-7

Helius (Helius) oosterbroeki n. sp.

Figures 5 and 6

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Type material. Holotype: No. 10189 (male); Dominican amber ( Lower Miocene ); Smithsonian Institution Entomology Departament; Brodzinsky / Lopez-Penha Collection.

Etymology. The name is dedicated to Prof. Pjotr Oosterbroek, the eminent specialist on Diptera , author of the Catalogue of the Craneflies of the World.

Diagnosis. Rostrum comparatively elongated, but a little shorter than the length of head, 1/3 the length of antenna, shorter than palpus; Rs very short; R 2+3+4 short, about 1/4 longer than Rs; d-cell rhomboid, 1/9 the length of wing; cross-vein m-cu at the bifurcation of Mb; outer gonostylus 1/4 longer than inner gonostylus.

Comparisons. Helius (H.) oosterbroeki n. sp. differs from H. collemus and H. (H.) neali n. sp. by the wing venation, but especially by the relation between the length of rostrum, palpus, antenna and head. In H. (H.) neali n. sp. rostrum is slightly longer than head, 1/5 the length of antenna while in H. (H.) oosterbroeki n. sp. rostrum is comparatively elongated, but a little shorter than head, 1/3 the length of antenna and is shorter than palpus. In H. collemus Podenas and Poinar, 2012 rostrum is as long as remainder of head and almost twice as long as palpus, antenna are longer than rostrum. Moreover, in H. (H.) oosterbroeki n. sp. is short, Rs is very short and R 2+3+4 about only 1/4 longer than Rs, in H. (H.) neali n. sp. vein R 2+3+4 is elongated, slightly curved and twice as long as vein Rs. Cross-vein m-cu in H. (H.) oosterbroeki n. sp. is at the bifurcation of Mb, H. (H.) neali n. sp. is situated in the middle of d-cell, in, in H. collemus this vein is positioned shortly before the fork of Mb. This new

PALAEO- ELECTRONICA.ORG species differ also from H. collemus and H. (H.) neali n. sp. by the morphology of male genitalia. In H. (H.) oosterbroeki n. sp. inner gonostylus is 1/4 shorter than outer gonostylus while in H. (H.) neali n. sp. inner gonostylus is twice as long as outer gonostylus.

Description. The body is brown, 3.25 mm long ( Figure 6.1 ). Head ( Figures 5.1 , 6.2 ): Rostrum comparatively elongated, a little shorter than the length of head 0.29 mm ( Figure 5.4 ), slightly widened at the end, width of head 0.55 mm; antenna 0.78 mm long ( Figure 5.2 ) 16-segmented; scape elongated, cylindrical; pedicel barrel-like; first flagellomere widened in the middle, twice as long as its width; the other flagellomeres oval, tapered toward the end of antennae; palpus 0.56 mm long ( Figure 5.3 ), almost twice as long as rostrum, the last segment of palpus is elongated, almost equal in length to the penultimate one and other taken together. Thorax: wing ( Figures 5.6 , 6.1 ) 3.85 mm long, approximately 1.30 mm wide; vein Sc ending opposite the bifurcation of Rb on Rs and R 1; Rs very short; sc-r two its length before the end of Sc; R 1 ending opposite 1/2 the length of R 2+3+4; R 2 (r-r) atrophied; R 2+3+4 short, only 1/4 longer than Rs; d-cell huge, narrowed at the basal part; the sector of M 1+2 from d-cell basal part to the edge of wing not more than twice as long as d-cell; m-cu at bifurcation of Mb; A 1 elongated, slightly waved; A 2 slightly arched. Abdomen ( Figure 6.1 ): hypopygium 0.51 mm long, gonocoxite elongated, three times longer than its width; inner gonostylus 1/4 shorter than outer gonostylus, strongly curved at the end directed to its basal part, widened at the base; outer gonostylus elongated, narrow, straight, slightly curved at the end; aedeagus elongated, wide ( Figures 5.5 , 6.3 ).

Figures

FIGURE 5. Helius (Helius) oosterbroeki n. sp., No. 10189 (male). 1, a drawing of the head (reconstructed) in frontoventral view; 2, a drawing of the right antenna in fronto-dorsal view; 3, a drawing of the right palpus in fronto-ventral view; 4, a schematic representation of the relation between the length of palpi (p), antenna (a), rostrum (r) and head (h); 5, a drawing of right gonocoxite and gonostyles in ventral view; and 6, a drawing of the right wing. Abbreviation: gx, gonocoxite; ing, inner gonostylus; oug, outer gonostylus.

FIGURE 6. Helius (Helius) oosterbroeki n. sp., No. 10189 (male). 1, a photograph of the body in ventral view; 2, a photograph of the head in fronto-ventral view; and 3, a photograph of hypopygium in ventral view.