Neurotoma silla sp. nov.

(Figs 1–17)

Description. Female. Holotype (Figs 1–6, 14). Length about 13 mm. Head, thorax and abdomen mainly black. Pale yellow are a minute spot at upper facial orbit, large subtrapezoidal mark between toruli, tegula, mesoscutellum, metascutellum, a small spot at posterior lateral corner of abdominal tergum 6, and a rather obscure, medially interrupted line along posterior margin of abdominal sterna 2–6. Mandible pale yellow, apically brownish and cutting edge blackish. Palpi mostly pale yellow. Antenna black, with outer surface of pedicel pale brown. Legs pale yellow, with following black: fore and mid coxae, fore and mid trochanters, basal 0.5 (anterior surface) to 0.7 (posterior surface) of fore femur (except for inner surface of trochantellus), basal 0.5 (anterior surface) to 0.7 (posterior surface) of mid femur (except for trochantellus), hind coxa (except for large posterior inner part ventrally), hind trochanter (except for outer surface) and obscure spot at base of hind femur; narrow apices of all tibiae and entire tarsi pale brownish. Forewing weakly blackish infuscated, with large cloud under stigma attaining posterior wing margin; hindwing almost clear hyaline in basal half and infuscated in apical half; veins and stigma black; veins R, Sc and 1A basally brownish.

Head with occipital carina sharply defined ventrally and laterally (Fig. 4); facial crest bluntly carinate; antennal furrow deep; frontoclypeal crest rather weakly swollen, rounded, its anterior end not triangularly flattened; anterior margin of clypeus not distinctly three lobed, with wide median part weakly roundly produced (Fig. 3). Vertex (upper part of head behind transverse and lateral transverse sutures) and temple covered with rather dense, deep, well separated punctures, interspaces smooth; frons (except for nearly impunctate slope close to torulus) and area between facial crest and lateral transverse suture densely, coarsely punctate (Fig. 3); paraantennal field smooth, impunctate; clypeus covered with dense, large, irregular punctures medially and along anterior margin; lateral parts rough but without distinct punctures. Head, except for paraantennal field, covered with very sparse, short, inconspicuous hairs, almost glabrous. Antenna with flagellomere 1 very weakly thickened medially and slightly thicker than succeeding flagellomeres but thinner than scape and pedicel; left antenna with 23 antennomeres (right one with apex missing); flagellomere 1 about 2.8 × length of 2. Cell C of forewing glabrous, with some pilosity in apical posterior part. Ovipositor sheath as in Fig. 6 (probably damaged in holotype).

Male. Paratype (Figs 7–13, 15–17). Length about 12 mm. Head, thorax and abdomen black, with a minute spot at upper facial orbit, large area covering clypeus (except for narrow anterior margin), lower part of frons and most of paraantennal field, tegula, a small obscure spot at posterior lateral corner of tergum 6, and a rather obscure, short line along posterior margin of sterna 3–7 pale yellow. Mandible pale yellow, apically brownish and cutting edge blackish. Palpi mostly pale yellow. Antenna dark brown to black, with scape and pedicel (except for inner dorsal black marks on both antennomeres) pale yellow. Legs pale yellow, with following black: fore and mid coxae, fore and mid trochanters, basal 0.5 (anterior surface) to 0.7 (posterior surface) of fore femur (except for inner surface of trochantellus), basal 0.5 (anterior surface) to 0.7 (posterior surface) of mid femur (except for trochantellus), hind coxa (except for large posterior inner part ventrally), and hind trochanter (except for apex); apical 0.75 of fore tibia, narrow apices of mid and hind tibiae and entire tarsi pale brownish. Wings as in female.

Structure and punctuation as in female. Both antennae with 21 antennomeres; flagellomere 1 about 2.5 × length of 2. Subgenital plate widely rounded towards narrowly truncated apex; genitalia as in Figs 16, 17.

Specimens examined. Holotype: ♀, South Korea [GB] Yecheon-gun, Bomun-myeon, Hakasan [36°40'N 128°35'E], 28. V. 2013, Seul-Ong Kim ; YNU Sym 17-0395. Paratype: 1♂, Mt. Undalsan (Gimryongsa) [36°45'N 128°12'E, Mungyeong-si, Gyeongsangbuk-do], 26. V. 2000, coll. S. J. Suh ; YNU Sym 17-0567.

Distribution. South Korea (Gyeongsangbuk-do).

Host plant. Unknown.

Etymology. The specific epithet is after the name of the powerful ancient kingdom of Silla, which ruled a large part of Korea, including the type locality of the new species. It is a noun in apposition.