subgenus Necrophila (Deutosilpha) Portevin, 1920

Deutosilpha Portevin, 1920: 396 (description, as subgenus of Eusilpha, type species: Silpha rufithorax Wiedemann, 1823, by monotypy)

Deutosilpha: Portevin, 1926: 108, 151 (redescription, as separate genus, catalogue)

Silpha (Deuterosilpha): Hatch 1928: 112 (catalogue, subsequent misspelling of Deutosilpha, as subgenus of Silpha) Necrophila (Deutosilpha): Peck 2001: 270 (catalogue, as subgenus of Necrophila)

Necrophila (Deutosilpha): Sikes 2008: 752 (catalogue, as subgenus of Necrophila)

Diagnostic description. Body flattened, length 17.5–22.5 mm. Head black with blue metallic lustre and yellow gula, antennae and mouthparts black. Pronotum orange with four black, glabrous spots, arranged in semi-circular position posteriorly on disc (Figs. 13–16). Scutellum, elytra, meso- and metathorax and legs black with blue metallic lustre. Abdomen black with metalic lustre, with pale posterior part of ventrite 8 and pale segments 9 and 10. Elytra dark blue to violet on outer lateral margins (on elytral epipleura), and light metallic blue on ventral surface (which is exposed probably only during flight).

Head flattened, with row of long erect black setae behind the eyes (Fig. 22). Frons with weakly indicated fovea between the eyes. Eyes small, not prominently protruding (Figs. 21–22). Antennae with loosely formed antennal club, consisting of 4 antennomeres (Fig. 15).

Pronotum hexagonal in shape (Figs. 21–22), with anterior margin only weakly emarginte, posterior margin straight medially (Figs. 21–22). Surface with uniformly dispersed, fine and dense, round punctures; more superficial on pronotal disc, without setation. Surface matt, with very fine isodiametrical microsculpture. Anterior and posterior margin with dense row of stout, short, yellow, ventrally oriented setae.

Scutellum large, with sinuous lateral margins (Figs. 13–16), densely covered by fine round punctures.

Elytra flattened with dorsally elevated, robust epipleural ridges on lateral margins. Each elytron with two weakly developed costae and abbreviated, outer third costa, which is only vestigial (Figs. 13–16). Elytral costae more distinctly delimited and elevated in females (Figs. 14, 16) than in males (Figs. 13, 15). Elytral epipleural ridge distinctly elevated along lateral margin, forming crest-like structures abruptly flattened postero-laterally in males (Figs. 13, 15; 17, 19), and gradually diminishing in females (Figs. 14, 16; 18, 20). Apex of elytron in males subtruncate to truncate with sinuous margin (Figs. 17, 19), in females elongate to slender, triangular or sinuate tip, sometimes with suture extended in distinct inner denticle (Figs. 18, 20). Dorsal surface with uniformly dispersed, fine and dense punctation, similar to that on pronotum; surface matt, with very fine, isodiametric microsculpture; without reticulate sculpture (which is present in Necrophila s. str.). Ventrally, elytra covered by densely arranged, large and strong punctures.

Hind wings fully developed, functional.

Metaventrite with dense, black pubescence and fine, transverse microsculpture.

Legs with bent tibia (more pronounced in males), tibia armed with several longitudinal rows of short, strong setae. Pro- and mesofemur with distal, ventrally oriented denticle in males (unmodified in females). Protarsomere 1–4 moderately expanded in males (unmodified in females). Metatarsal claws asymmetrical in males (Fig. 27), with inner claw distinctly longer and more robust than the outer one (almost symmetrical, of the comparable size in females, Fig. 28).

Abdomen very tightly fixed by ventrally expanded elytral epipleura.

Male. Genital segment with longitudinal ventrite 9, reaching anterior margin of tergum 9 (Figs. 3, 8); spiculum gastrale medium in size, relatively slender, slightly asymmetrical (Figs. 2–3, 7–8). Aedeagus small; with slender paramerae and median lobe regularly tapering to a triangular tip (Figs. 1, 6).

Female. Genital segment with tergum 10 hexagonal in shape in dorsal view (Figs. 4, 9, 11), with stylus inserted laterally, shorter than apex of coxite in ventral view (Figs. 5, 10, 12).