Dorytomus mikhailovi, Legalov & Nazarenko & Perkovsky, 2021

Legalov, Andrei A., Nazarenko, Vitaliy Y. & Perkovsky, Evgeny E., 2021, A new species of the genus Dorytomus Germar, 1817 (Coleoptera, Curculionidae) from Rovno amber, Zootaxa 5006 (1), pp. 95-100 : 96-98

Dorytomus mikhailovi sp. n.

( Figs 1–8 )

urn:lsid:zoobank.org:act:B643151C-C5F5-4789-9234-0C7D8F667C71

Material. Holotype, female, SIZK OL-434 , Olevsk, Zhitomir region, Rovno amber, late Eocene. Syninclusions: SIZK OL-432 Cecydomyiidae , SIZK OL-433 Mycetophidae.

Description. Female. body black, distinctly shining. Dorsum covered with two types of hairs: semierect to erect, sparse, stout scale-like setae and decumbent, rather sparse, fine setae.

Rostrum long, 6.9 times as long as wide at apex, 5.9 times as long as wide at base, 1.6 times as long as pronotum, distinctly curved, thicker than tibiae, densely punctate. Antennal scrobes lateral and directed toward eye base, not seen in anterior part. Forehead slightly narrower than base of rostrum. Eyes large, not projecting beyond head outline, coarsely faceted. Vertex finely punctate. Temples short. Antennae inserted before middle of rostrum. Scape elongated, almost reaching eye. Flagellum 7-segmented, with subconical antennomeres. Antennomere 2 longer than antennomeres 3 and 4 combined. Antennal club relatively wide and long, compact.

Pronotum densely and coarsely punctate, weakly flattened, with median line. Puncturation subequal to interstriae between punctures, decreasing towards middle of pronotum. Scutellum large, subtriangular.

Elytra convex, about 1.2 times as long as wide in middle, 3.1 times as long as pronotum. Humeri weakly convex. Elytral striae distinct, relatively deep, 9th stria close to 10th stria at level of metacoxae. Interstriae 3.3-4.0 times as wide as striae, flattened, finely punctate, covered with fine decumbent setation, with row of erect to semierect scale-like setae. Pygidium covered by elytra.

Prosternum weakly convex, densely punctuate, without ventral channel. Pre- and postcoxal portions of prosternum equal in length. Procoxae 1.5 times as long as precoxal portion. Metaventrite 2.0 times as long as length of metacoxae, densely punctuate. Metaepisternum narrow, 6.9 times as long as wide in middle, densely and coarsely punctate.

Abdomen convex, punctate. Ventrites 1 and 2 elongate, sparsely punctate. Ventrite 1, 1.3 times as long as length of metacoxae. Ventrite 2, 1.1 times as long as ventrite 1. Ventrites 3 and 4 short. Ventrite 3, 0.6 times as long as ventrite 2. Ventrite 4, 0.8 times as long as ventrite 3. Ventrite 5, 2.4 times as long as ventrite 4.

Legs long. Procoxae almost conical, located near middle of prosternum. Mesocoxae rounded and separated. Metacoxae transverse, shorter than ventrite 1. Femora thickened, punctate, with large teeth. Tibiae elongated, punctate, with distinct uncus. Protibiae not crenulated on the inner margin. Tarsi elongated. Tarsomere 1 elongate-conical. Tarsomere 2 conical. Tarsomere 3 bilobed. Tarsomere 5 elongate, with free claws.

Body length without rostrum 2.7 mm; rostrum length 0.9 mm.

Male unknown.

Note. The convex abdomen indicates that this specimen is female.

Etymology. The species is named in honour of Dr. Kirill Mikhailov.

Diagnosis. The new species is similar to D. groehni but differs in shorter rostrum (6.9 times as long as wide at apex), dorsum covered with denser decumbent hairs and erect to semierect scale-like setae, and smaller body sizes (2.7 mm). It is distinguished from D. bukejsi by the densely punctate pronotum, longer rostrum and wide elytral interstriae. The new species differs from D. vlaskini by the elytral interstriae covered with decumbent hairs and erect to semierect scale-like setae, shorter rostrum and coarsely punctuate pronotum.

Remarks. The new species belongs to the tribe Dorytomini based on the antennal scrobe directed toward the eye, not visible in anterior part, prosternum without ventral channel, tarsomere 3 bilobed, the precoxal portion of the prosternum elongated, the flagellum is 7-segmented, femora with teeth, the claws are simple and the tibiae have an uncus and the sutures are straight between the abdominal ventrites. The new species belongs to the genus Dorytomus based on the protibiae not being crenulated on the inner margin.

Figures

FIGURES 1–4. Dorytomus mikhailovi sp. n., holotype, female: 1—habitus, dorsal view; 1—habitus, ventral view; 3—habitus, lateral view, left; 4—habitus, lateral view, right.

FIGURES 5–8. Dorytomus mikhailovi sp. n., holotype, female, body outline: 5—habitus, dorsal view; 6—habitus, ventral view; 7—habitus, lateral view, left; 8—habitus, lateral view, right. Scale bar = 0.5 mm.