Diodesma slipinskii

Alekseev, Vitalii I. & Bukejs, Andris, 2016, New Zopheridae (Coleoptera: Tenebrionoidea) from Baltic amber, Zootaxa 4178 (3), pp. 409-427 : 414-415

D. slipinskii Alekseev & Bukejs sp. nov.

( Figs 7–9 , 24)

Type material. Holotype: Nr. 731-1 [CCHH] “Holotype / Diodesma slipinskii sp. nov. / des. Alekseev V.I. & Bukejs A.” [red hand-written label]; sex unknown. Complete beetle is included in a small, transparent, yellow amber piece embedded in block of GTS-polyester resin with dimensions 18 × 6 × 6 mm. Syninclusions are seven stellate Fagacean hairs and one mite (length 0.35 mm). Amber piece with inclusion possibly thermally treated in autoclave.

Type strata. Baltic amber, Upper Eocene , Prussian Formation (Priabonian). Estimated age: 37.2–33.9 Ma.

Type locality. Yantarny settlement (formerly Palmnicken), Sambian (Samland) Peninsula, Kaliningrad region, Russia.

Differential diagnosis. Diodesma slipinskii sp. nov. differs from extant species of the genus in the following combination of characters: pronotum with protruding anterior angles; lateral sides of pronotum weakly explanate and flattened anteriad; elytra with small punctures; antennomere 10 subquadrate.

Description. Body length about 2.25 mm, maximum height and width (at middle of elytra) 0.68 and 0.95 mm respectively; body elongate, strongly convex dorsally, flattened ventrally; body and appendages apparently uniformly black in colour.

Head. 1.5× as wide as long; distinctly widest between antennae; vertex covered with dense, small, round, unisetose granules; frons and clypeus sparsely punctured and setose. Anterior clypeal margin widely rounded. Eyes large, prominent, conical, with coarse facets; interfacetal setae not apparent; distance between eye and antennal insertion slightly shorter than scape length. Maxillary palpus 4-segmented, short; palpomere 4 broad, oval-shaped. Labial palpus 3-segmented, palpomere 3 largest, ovate. Antennae short, extending to middle of pronotum; 11- segmented with 2-segmented club, densely covered with dark, straight semierect setae. Scape, pedicel and antennomere 3 elongate; antennomeres 4–9 transverse; antennomere 10 subquadrate; antennomere 11 rounded. Antennomere length ratios: 6-5-5-4-4-3-3-3-3-5-3.

Thorax. Pronotum transverse, 1.2× as wide as long, widest at middle; pronotal disc convex, densely covered with unisetose granules (distinctly larger than granules on head). Lateral sides weakly explanate and flattened anteriad. Anterior margin arcuate; lateral and posterior margins rounded; anterior angles triangular, acute, prominent, reaching middle of eye; posterior angles obtuse. Pro-, meso- and metasternum weakly rugose. Procoxal cavities open posteriorly, meso- and metacoxal cavities closed. All coxae separated: procoxae by elongate (3:1 length to width ratio), parallel-sided prosternal process; mesocoxae by distance approximately 0.3 of coxal diameter; metacoxae by intercoxal process of ventrite 1 (slightly narrower than metacoxal diameter).

Scutellum small, indistinct. Elytra ovate, length 1.5 mm, width 0.95 mm; strongly convex dorsally, slightly wider than pronotum at humeri, jointly rounded apically; weakly rugose at disc and crenulated laterally in basal one-fourth of length. Humeral angles rounded. Each elytron with 10 rows of small, round punctures, distance between strial punctures equal to 1.5–2.0× diameter of one puncture; intervals flat, distance between striae approximately 3–4× diameter of single puncture. Strial punctures bearing long, curved setae. Scutellary striole not apparent. Epipleura well-developed, reaching apex of elytra, widest at humeral angle. Hind wings not apparent. Ratio of lengths of mesoventrite to metaventrite to abdomen: 3-3-14.

Abdomen. With five visible, similarly articulated ventrites. Ventrite length ratios: 22-14-11-9-10. Setation of ventrites not apparent (possibly absent); ventrite 5 rounded apically. Intercoxal process of abdominal ventrite 1 rounded.

Legs. Tarsi tetramerous. Length of apical tarsomere equal to combined length of tarsomeres 1–3; tarsomere 3 smallest. Tarsal claws simple, large, equal in size, with length about one-third of tarsomere 4.

Etymology. Patronymic, this new species is named in honor of a renowned coleopterist and specialist on zopherid beetles, Dr. Adam Ślipiński (CSIRO, Canberra, Australia)

Figures

FIGURES 7 – 9. Diodesma slipinskii sp. nov., holotype: 7 — habitus, dorsal view; 8 — habitus, ventral view; 9 — habitus, lateral view.