Picemelinus irinae, Alekseev, Vitalii I. & Grzymala, Traci L., 2015

Alekseev, Vitalii I. & Grzymala, Traci L., 2015, New Aderidae (Coleoptera: Tenebrionoidea) from Baltic and Bitterfeld amber, Zootaxa 3956 (2), pp. 239-257 : 244-245

Picemelinus irinae sp. nov. Alekseev & Grzymala

( Figs. 8–9 )

Material examined. Holotype No. 890-5 [ CCHH], male ( Figs. 8–9 ). The beetle inclusion is preserved in a polished piece of transparent amber with a yellowish shade without any further fixation. The piece is small, irregular in form, with maximum length 12 mm and maximum width 8 mm. The syninclusions are represented by two trichomes.

Etymology. Matronymic, this new species is dedicated to the mother of the first author—Irina I. Alekseeva.

Type strata. Baltic Amber. Eocene.

Type locality. Russia, the Kaliningrad region, the Sambian [Samland] peninsula, Yantarny settlement [formerly Palmnicken].

Description. Length 1.8 mm; moderately convex, elongate. Unicolored, black. Upper surface biseriate, clothed with very short pubescence, one seta arising anterad of each puncture, with additional short, numerous setae between primary pubescence (pruinose pubescence). Body length 1.9× maximum body width. Elytral length 3.6× pronotal length.

Head. Eyes large, oval, hemispherical, with slight anterior emargination, well-separated from hind margin of head; interocular space narrower than one ocular diameter; temples approximately 1/3 of minimum ocular diameter; apical maxillary palpomere elongate triangular; vertex covered by pubescence equal in length and width to elytral pubescence. Antenna ( Fig. 8 B) filiform, 11-segmented, pubescent, reaching middle of elytra when folded backward; scape, antennomere III, and antennomere XI longest; antennomere length ratios: 14-4-20-5 -5-6-6- 6-6-6- 11; antennomere III with two apical projections forming cavity for antennomere IV.

Thorax. Pronotum ( Fig. 8 A) transverse, width 0.7× length, widest apically, with very shallow impression laterad of basal angle, disc with pubescence indistinct, punctation dense and coarse. Scutellum subquadrate, without visible punctation or pubescence. Elytron with short, simple pubescence, moderately convex, with slight depression on disc in basal third near suture; sides weakly rounded; width 0.7× length; punctation dense and coarse; punctures finer towards lateral aspects of disc.

Abdomen. Separation of abdominal ventrite I and abdominal ventrite II visible medially and laterally. Legs. Metafemur simple, without visible brush or comb of modified setae. Metatarsomere I length 3.0× metatarsomeres II–IV combined, metatarsomere II bilobed, metatarsomere III concealed.

Diagnosis. Picemelinus irinae sp. nov. differs from the only extant described member of this genus from Japan, Picemelinus flabellicornis (Pic, 1910) , by the simple instead of flabellate antennomeres V–X. The elongate scape and the very distinctive length and shape of antennomere III provide evidence for the congeneric status of these two species.

Figures

FIGURES 8. Picemelinus irinae sp. nov. illustrations. A. forebody, B. antenna.

FIGURES 9. Picemelinus irinae sp. nov. habitus photograph. Holotype, lateral view. Scale bar = 1.0 mm.