Psilomma Förster, a small and rare genus within the tribe Pantolytini (Diapriidae: Belytinae), consists of three species, P. dubiumKieffer, 1908; P. fuscicornisKieffer, 1908; P. fusciscapisFörster, 1861, widely distributed in Europe (Macek, 1990). This genus is easily distinguished from other Pantolytini genera by the sickle form of mandibles. To date, Psilomma has not yet been recorded outside of Europe.

As a result of the present study, the genus Psilomma is reported from South Korea for the first time based on a species of P. dubium. In addition, the known range of Psilomma is extended from European countries (Western Palaearctic) to South Korea (Eastern Palaearctic). Here, detailed redescription and photographs of this species are provided.

Materials and Methods

Morphological terms generally follows Nixon (1957) and Macek (1990), and terms for wing venation follow Masner & García (2002). The images were captured with an Axiocam HRc camera through a Discovery V20 stereomicroscopy (Carl Zeiss, Oberkochen, Germany) and were produced with Axio Vision40AC software (Carl Zeiss, Oberkochen, Germany). Final plates were prepared in Adobe Photoshop CS6 (Adobe Systems Incorporated, San Jose, United States of America).

The following abbreviations are used throughout the text: YNU, Department of Life Sciences, Yeungnam University, Gyeongsan, South Korea; POL, distance between the inner edges of the two lateral ocelli; OOL, distance from the outer edge of a lateral ocellus to the compound eye; MT, Malaise Trap.

Systematic accounts

Family Diapriidae Haliday, 1833 염주벌과 (신칭)

Subfamily Belytinae Förster, 1856 어리염주벌아과 (신칭)

Tribe Pantolytini Hellén, 1964 점어리염주벌족 (신칭)

Genus PsilommaFörster 1856 낫어리염주벌속 (신칭)

PsilommaFörster 1856: 128, 130, 132. Type species: Psilomma fusciscapis Förster, first included species.

Diagnosis. Mandibles sickle-shaped, overcrossing apically; female antenna 15-segmented, scape with simple apical rim, flagellomeres gradually widened and shortened to apex; male antenna 14-segmented, filiform, distinctly longer than wide; eyes bare or sparsely setae; epomia absent; radial cell reduced, indistinct or absent; femora slender with long femoral stalk; petiole cylindrical; gaster fusiform, sharply pointed to apex.

Psilomma dubiumKieffer, 1908 낫어리염주벌 (신칭) (Figs. 1-5)

Psilomma dubiaKieffer, 1908: 426.

Psilomma atricepsKieffer, 1908: 422.

Psilomma flavipesKieffer, 1908: 423.

Psilomma crassicornisKieffer, 1908: 425.

Psilomma dubium Kieffer: Johnson, 1992: 105.

Redescription of female.

Color. Head black; antenna brown; palps yellow; legs, tegula yellowish brown; mesosoma and metasoma dark brown to blackish brown.

Head. Slightly wider than long (7: 6) in dorsal view, slightly narrower than mesosoma (34: 35), OOL longer than POL (11: 9); occipital carina distinct, covered with dense whitish setae; vertex and frons smooth with sparse setae; tentorial pit large and deep; clypeus smooth and distinctly convex; mandibles sickle-shaped, overcrossing apically, asymmetrical; head in lateral view slightly shorter than height (11: 10), with protrusive antennal shelf; eye bare, much shorter than height of head (11: 28), slightly shorter than malar space (11: 12); antenna much shorter than body length (19: 30) and covered with short dense setae; antennal segments in the following proportions (length: width): 48: 9; 10: 7; 18: 6; 10: 6; 10: 6; 10: 7; 9: 7; 9: 7; 8: 7; 8: 7; 8: 7; 8: 7; 8: 7; 7: 8; 14: 8.

Mesosoma. Distinctly longer than width (45: 29) in dorsal view; cervix short and stout; pronotum short and covered with setae; pronotal shoulders angled; mesoscutum flattened and bare; notauli complete; humeral sulcus distinct; scutellum smooth, bare and slightly convex; anterior scutellar pit large and deep, transverse (17: 13), as long as remaining scutellar disc; posterior scutellar pits absent; mesosoma in lateral view clearly longer than height (3: 2); lateral part of pronotum smooth, bare and shiny; upper part of mesopleuron smooth, bare and shiny with deep sulcus under tegula, without sternaulus; lower part of mesopleuron smooth and covered with sparse setae; median keel of dorsellum prominent, tubercle-shaped; posterior margin of propodeum slightly emarginated; median propodeal keel simple.

Wing. Fore wing with basal, costal, subcostal, marginal, radial and stigmal veins tubular; radial vein shortly indicated; stigmal vein short, as long as one third of marginal vein and postmaginal vein.

Metasoma. Petiole cylindrical in dorsal view smooth, bare, shiny, with irregular longitudinal keels and dense cushion of long setae ventrally; base of tergite II with several costae and short median furrow.

Measurements. Head length 0.63 mm, width 0.68 mm; mesosoma length 1.10 mm, width 0.70 mm; metasoma length 2.06 mm; fore wing length 2.95 mm; total body length 3.79 mm.

Male. Body length 3.29 mm. Similar to female, but antenna filiform, long and slender; antennal segment III (A3) slightly emarginated basally; antennal segments in following proportions: 28: 8; 7: 7; 25: 6; 24: 5; 22: 5; 22: 5; 22: 5; 21: 5; 20: 4; 20: 4; 18: 4; 18: 4; 18: 4; 22: 4.

Material examined (2♀♀2♂♂). South Korea: 1♀2♂♂, Gangwon-do, Wonju-si, Socho-myeon, Hakgong-ri, Mt. Chiaksan, 37°22'18"N, 128°03'01"E, 20.VI-19.VII.2013 (MT), J.W. Lee (YNU); 1♀, Gyeongsangbuk-do, Cheongdo-gun, Unmunmyeon, Ssalbawi, 35°38'08"N, 129°01'27"E, 29.VI-10.VII.2012 (MT), J.W. Lee (YNU).

Distribution. South Korea (new record), Armenia, Austria, Czech Republic, Denmark, France, Finland, Hungary, Ireland, Poland, Slovakia, Sweden, Switzerland, United Kingdom.

Host. Unknown.