Pedostrangalia (s. str.) ostensackeni, Vitali, 2023

Vitali, Francesco, 2023, New and little-known Lepturinae from succinite (Coleoptera Cerambycidae), Baltic Journal of Coleopterology 23 (2), pp. 189-203 : 189-203

Pedostrangalia (s. str.) ostensackeni n. sp.

( Figs. 4-6 )

Holotype. Male, Baltic amber, ex coll. M. Veta 210415, author’s coll. FS83BS51 ( Fig. 4-5 ).

The beetle is preserved inside a circular piece of amber measuring ~ 20 mm in diameter. It lacks antennomeres VIII-XI and the body looks to have been subject to a strong deformation of the amber. The humeri look laminiform, the coxae look flattened and pulled backwards, while the abdomen is almost dislocated backwards. The amber piece contains one stellate fagacean trichome.

Differential diagnosis

The fossil has been identified as a member of the genus Pedostrangalia (s. str.) for the following combination of characters: prosternum convex, not forming an angle with the intercoxal process ( Lepturini ); cheeks developed: head with distinct angulated

193 temples; pronotum without apical collar and with acute basal angles; elytra not shortened, posteriorly convergent and not round- ed at apex; antennae long and not strongly dentate. In addition, the pronotum is laterally winkled.

The peculiar character of the furrowed tarsi in not visible, but other genera show either strongly reduced temples or a pronotal collar.

With respect to P. pristina , P. ostensackeni n. sp. shows coloration entirely black, habitus more elongated, pronotum more cylindrical and with lateral angles, elytra 3.3 as long as wide at shoulders (2.6 in P. pristina ) and more slender antennae, whose last antennomere is pedunculate or sub-articulated.

With respect to the congeners of the Recent, P. ostensackeni sp. n. seems to show most affinity with the Caucasian P. tokatensis Sama, 1996 , which is characterised by analogous habitus and an atypical furrow behind the posterior margin of the eyes (unnoticed in the original description). The fossil differs in the pronotum laterally toothed, the longer elytra spines and (possibly) the black body colour. P. ostensackeni sp. n. reminds also of some Neosphenalia , e.g., the Manchurian P. femoralis (Motschulsky, 1860) , which especially differs in the shorter temples.

Description

Undetermined sex, probably male; length 7.5 mm. General habitus small, elongated; body seemingly black, ventral side covered with dense light pubescence.

Head relatively short; cheeks developed but relatively short; clypeus and forehead transverse; antennal tubercles widely separated, fairly elevated; eyes relatively close to the base of the mandibles, emarginate at

194 the upper side, uniformly convex at the un- der one, finely faceted; temples relatively long, inferiorly as long as cheeks, parallel-sided, abruptly converging backward, transversely furrowed behind the posterior margin of the eyes; neck as long as temples. Last (IV) maxillar palpomere widened and transversely truncate at apex; III palpomere widened at apex, three-fourth as long as IV; II palpomere elongated, as long as IV. Antennae 11-segmented, last antennomere seemingly peduculate or sub-articulated, inserted between the eyes, hardly reaching the elytral apex, glabrous, extremely finely and densely punctured; scape feebly bowed; pedicle twice longer than broad, nearly one-fourth as long as scape; antennomere III more than one-fourth longer than scape; antennomere IV hardly longer than scape; antennomere V as long as III; following antennomeres decreasing in length, except for the last, about as long as VII; proportions according to the formula: 3.8: 1.0: 5.0: 4.0: 5.0: 3.8: 3.2: 2.8: 2.8: 2.7: 3.1.

Prothorax transverse, bell-shaped; sides with a stout angle before the middle; hind angles acute, embracing the elytral base; apex concave, deeply furrowed and bordered; base posteriorly lobed in the middle, finely grooved; disc feebly convex above, without longitudinal furrow, entirely covered with an extremely fine dense puncturing and indistinct pubescence. Scutellum small, elongate, forming an isosceles triangle.

Elytra long, 3.7 times as long as pronotum, 3.3 times as long as wide at the shoulders, flat above, feebly constricted at the sides after humeri, then nearly parallel-sided, apically tapered shortly before apex and obliquely emarginated at the apex; marginal apex acute; surface covered with a coarsely dense puncturing and an extremely fine, nearly invisible, short recumbent pubescence.

Ventral side convex, apparently impunctate and covered with a dense recumbent pubescence; prosternum nearly straight in lateral view.

Legs long; femora slightly club-shaped; tibiae linear, rectilinearly truncated at the apex, finely punctured and pubescent; apex of mesotibiae armed with two equal spines; apex of metatibiae with two unequal spines, the longest one being one-third as long as metatarsomere I. Metatarsi narrow, long, about one-fifth shorter than the metatibiae; metatasomere I about as long as the following articles together; metatarsomere II one-half longer than III; metatarsomere III one-fourth as long as I, incised at the apex more than one-half of its length; metatarsomere IV minute; onychium as long as II (proportions according to the formula: 4: 1.5: 1:?: 1.5).

Etymology

This species is dedicated to Carl-Robert Osten-Sacken (1828-1906), eminent dipterologist of Baltic German origin and Russian consul in the United States for reminding the strength links among European peoples.

Figures

Fig. 4. Pedostrangalia ostensackeni n. sp., Holotype, lateral view.

Fig. 5. Pedostrangalia ostensackenin. sp., Holotype, dorsal view.

Fig. 6. Pedostrangalia ostensackeni n. sp., Holotype, reconstruction.