Vabole triplehorni Alekseev and Nabozhenko

Alekseev, Vitalii I. & Nabozhenko, Maxim, 2015, A New Fossiltenebrionid Beetle of the Tribe Palorini (Coleoptera: Tenebrionidae) from Eocene Baltic Amber, The Coleopterists Bulletin (mo 14) 69, pp. 127-130 : 128-130

Vabole triplehorni Alekseev and Nabozhenko , new species

( Figs. 1–5 )

Description. Body: TL = 2.3 mm, EW = 0.75 mm. Habitus ( Figs. 1–5 ) elongate (TL/EW = 3.0), subparallel, narrow, glabrous, shiny; body and appendages uniformly dark brown. Head: Wide (0.57 mm); not constricted behind eyes, finely and moderately closely punctured. Supraorbital carina not developed. Frontoclypeus simple, without tubercles and raised borders, arcuate. Eyes lateral, entire, finely faceted, small and rounded. Interfacetal setae not apparent (at 56X magnification). Subantennal grooves absent. Punctures on head about as large as eye facet and separated by 1 diameter or more. Sides of frons not extending backwards; anterior margin of eyes visible from above. Antennae short, stout, flattened; reaching middle of pronotum; apparently 10-segmented; without distinct club. Last antennomere (XI) reduced, very short. Maxillary palps with apical segment fusiform. Thorax: PL = 0.63 mm, PW = 0.53 mm; pronotum slightly flattened dorsally, without depressions, transverse (PL/PW = 1.2). Pronotal disc with small, sparse, round, irregular punctures on disc (distance between punctures about twice as large as diameter of puncture). Sides of pronotum smooth, finely beaded with coarser and denser punctation (distance between punctures less than diameter of puncture). Pronotal anterior angles widely rounded; posterior angles triangular; basal margin almost straight, entirely and narrowly beaded. Tergosternal sutures of prothorax present. Hypomeron lacking antennal cavities. Prohypomera with coarse, moderately dense punctation, punctures large, round, subequal to distance between them. Prosternal process expanded and rounded apically, 1.5 times wider than procoxal diameter, densely punctured. Femoral lines absent. Scutellum: Transverse (2.5 times wider as long), angulate, with rounded angles, without punctures. Elytra: EL = 1.4 mm, EW = 0.75 mm; subparallel-sided; truncate apically; slightly depressed from above; exposing part of last tergite. Elytron with 9 rows of strial punctures, intervals between strial punctures separated by 2 times puncture diameter. Scutellary striole absent. Interstices uniseriate-punctate. Elytral intervals flat, interval between striae 5–6 slightly raised. Elytral epipleuron tapering gradually posteriorly, attaining elytral apex. Hind wings fully developed. Abdomen: With five ventrites (relative lengths of ventrites 17-12-10- 11-14); ventrites with small, irregularly placed punctures, which are lesser than punctres on thorax ventrally; intercoxal apophysis wide and rounded, about twice wider than metacoxal diameter. Legs: Tarsal formula 4-4-4; pro- and mesocoxae rounded, widely placed, metacoxa transverse, exposed. All tibiae with 6–7 sharp, small spines along inner margin and with 2 acute, short spurs. Protibia with furrow along outer margin. Length of apical tarsomere equal to combined length of tarsomeres 2–3. Tarsal claws simple, large, equal in size, length about half of apical tarsomere.

Stratigraphic and Geographic Range. Eocene amber of Central Europe.

Etymology. The species is named in honor of the famous coleopterist and specialist on darkling beetles, Charles A. Triplehorn.

Type Material. Holotype: Nr. 1470-4 [ CCHH], sex unknown. The complete beetle inclusion with partially exposed hind wings is preserved in a small polished piece of transparent amber, yellow in color, with two gas bubbles and some cracks. The amber piece is embedded in a block of polyester resin with the dimensions 9 × 9 × 3 mm. The animal syninclusions are represented by three phoretic mites (Acari: Acariformes), attached to the head (1) and thorax (2) of the beetle.

Type Locality and Horizon. Baltic Amber. Eocene. Baltic Sea coast.

Diagnosis. As for the monotypic genus.

Figures

Figs. 1–3. Vabole triplehorni, habitus. 1) Dorsal view; 2) Ventral view; 3) Lateral view.

Figs. 4–5. Vabole triplehorni, habitus, reconstructions. 4) Dorsal view; 5) Ventral view.