Plectrocnemia aristovi Melnitsky & Ivanov sp. nov.

(Figs 1, 2)

Holotype. Male. SIZK K–8734.

Etymology. The species is named in memory of the late Russian paleoentomologist Daniil Sergeevich Aristov.

Locality and horizon. Priabonian Rovno amber, Ukraine; late Eocene.

Description. Body length 3.9 mm; forewing length 4.8 mm. Head, antennae, palps, legs and thorax brown.Wings and abdomen brownish. Head with brown hairs. Antennae with long hairs and small sparkling dots probably representing the pseudoplacoid sensilla. Palps with annulated long terminal segments, basal segments of maxillary palps have short, strong chaetoid sensilla. The lateral sternal processes of the 5th abdominal segment long, wide, well sclerotized at the basal part and thin at the apex.

Male genitalia. Ventral part of inferior appendages elongate; covered apically with pale hairs. Dorsal part of inferior appendages makes clavate process directed upwards and covered with hairs. Segment IX very narrow. Segment X small, with smooth posterior margin. Preanal appendages (cerci) elongate with strongly sclerotized triangular lower part; their apical parts with long thick setae, dorsal surface with hairs. Aedeagus long and wide; its apex elongate and narrowed, with a large subapical spine directed upwards and backwards.

Remarks. The new species is similar to Plectrocnemia kirmikhia Melnitsky, Ivanov & Perkovsky, 2021 from Rovno amber but differs in the shape of the preanal appendages and aedeagus: the preanal appendages in the latter species oblong with small ventral pointed process, and without long apical setae; aedeagus with rounded apex bearing four thick, curved spines on the dorsal surface.