Electotreta gen. n.

Type species: Electotreta rasnitsyni sp. n.

Description. Adult male. Alate, flattened, elongate (Fig. 4). Head transverse, almost completely covered by pronotum. Eyes relatively large, spherical. Ultimate palpomeres distally pointed. Antennal sockets broadly separated. Antenna 11-segmented, moderately long, filiform; pedicel (antennomeres 2) subequal in length to antennomere 3 and subsequent antennomeres; pubescence on antennomeres 3–11 short and sub-erect (Figs 4–5).

Pronotum small, ca. 6 times shorter than elytra, transverse, narrowed and rounded anteriorly, with smooth convex disk and prominent acute posterior angles (Fig. 4). Scutellum triangular, with minute emarginate at apex (Fig. 4). Elytra elongate, flattened, parallel-sided, with prominent humeral costa, noticeable in proximal three fourths, and ten rows of even round impressions, six rows in discal part and four rows in lateral part, apices independently rounded; pubescence sub-erect and short (Fig. 4). Epipleuron short, noticeable near humerus (Fig. 5). Metathoracic wings fully developed.

Legs slender; trochanters elongate; femurs and tibiae narrow, tibiae straight, slightly widened distally; tarsomeres 2–4 slightly widened, with plantar pads; claws simple, with a small broad tooth at base.

Abdomen with six ventrites, strongly narrowed distally; ultimate ventrite elongate, almost parallel-sided; penultimate equally narrow, short. Ventrites without photic organs.

Female. Unknown.

Diagnosis. Electotreta gen. n. is easily distinguishable from other ototretines by the dorsally smooth head, transverse pronotum with prominent acute posterior angles and ten rows of round impressions on each elytron (Fig. 4).

Etymology. The name of the new genus is derived from "electron", the Greek for "amber", and the genus name "Ototreta". Gender feminine.

Remarks. Ototretines ( Drilaster, Stenocladius Fairmaire, 1878 and allied genera), initially treated as drilids (e.g., Wittmer, 1944), were afterwards included in Lampyridae (McDermott, 1964; Crowson, 1972), and recently transferred to Cantharidae (Bouchard et al., 2011) . However, the latter transfer was made without argumentation, and this lineage perhaps should be retained in Lampyridae, pending further study, as apparently not fitting in Cantharidae, due to, for instance, the free labrum of its representatives, as opposed to the fused labrum in the cantharids. Obviously, these East-Asian beetles need to be comprehensively studied to be properly classified.

Most of the head and thoracic structures of the inclusion are obscured below by air bulbs and detritus particles.