The female of Baeosega is superficially similar to Nipponosega and Okinawasega. However, the occipital carina is developed and reaching lower gena in Nipponosega (absent in Baeosega) and the deep malar sulcus is present in Okinawasega (only faintly indicated in Baeosega). The male is very similar to Okinawasega. The longer setae on flagellum and remarkably long R1 of the forewing are useful characters distinguishing Okinawasega from Baeosega. Compared to the above two genera, the male of Nipponosega has the pronotum short. The pronotum of Baeosega and Okinawasega is as long as or longer than mesoscutum but it is shorter in Nipponosega. Compared to genera found in South Asia, Baeosega is most similar to Serendibula. In the female of Baeosega, the metasomal T2 is lacking fine longitudinal carinae whereas T2 of Serendibula is covered with fine carinae. The male of Baeosega can be distinguished from Serendibula by having longer setae on antennal flagellomeres, the shorter metanotum, almost half as long as mesoscutellum (metanotum is longer, almost as long as mesoscutellum in Serendibula) and the tubular distal apex of pterostigma (very sharp in Serendibula). The inner tooth of tarsal claw is minute and indistinct in both female and male of Baeosega, whereas the inner tooth is distinctively large in Serendibula.

Female. Clypeal apex not thickened; malar sulcus absent or indicated as faint track; scapal basin shallow, cross-ridged, median longitudinal carina absent; occipital carina absent, at most posterior margin of vertex forming corner behind ocellar triangle; eye setose; flagellum fusiform, intermediate segments broader than long, and with ventral surface flattened. Mesosoma slender, dorsum more or less punctate; pronotum with median groove and shallow pit before lateral lobe, 1.0–1.4 × as long as combined length of mesoscutum, mesoscutellum and metanotum; mesoscutum with notauli; parapsides lacking; posterolateral corner of mesoscutum not lobate; micropterous (Fig. 1A, B), forewing pads extending to posterior margin of mesoscutellum; mesopleuron with omaulus, without scrobal sulcus; metanotum triangular and small, ca. 2/3 as long as mesoscutellum; propodeum with long dorsal surface and a pair of recumbent teeth present, meeting or almost meeting together, dorsal posterolateral angles bluntly angulate, lateral and posterior surfaces abruptly declivous. Hind coxa with dorsobasal carina; tarsal claws with a minute inner tooth. Metasoma smooth, shagreened or weakly granulated, without longitudinally striate area.

Figure 1. 

General habitus of Amiseginae A Baeosega humida Krombein, holotype ♀ B B. torrida Krombein, holotype ♀ C ditto, allotype ♂ D Nipponosega lineata sp. nov., holotype ♀. Scale bars: 1.0 mm.

Male. Clypeal apex not thickened; scapal basin flat or weakly excavated, cross-ridged; malar sulcus present; occipital carina absent; eye setose; antenna elongate, F3 2.7–3.5 × longer than wide. Mesosoma slender, dorsum densely punctate; pronotum with median groove and shallow pit before lateral lobe, slightly longer than mesoscutum, 0.5–0.6 × as long as combined length of mesoscutum, mesoscutellum and metanotum; mesoscutum with notauli; parapsidal line faintly indicated; mesopleuron without omaulus and scrobal sulcus; metanotum approximately half mesoscutellum; a pair of recumbent teeth present, meeting or almost meeting together; propodeum with dorsal posterolateral angles bluntly angulate, posterior surface abruptly declivous; fully winged (Fig. 1C), pterostigma thin; R1 not indicated, distal apex tubular; Rs extended by weakly curved dark streak; medial vein arising before cu-a. Hind coxa with dorsobasal carina; tarsal claws with a minute inner tooth. Metasoma sparsely punctate with smooth interspaces.

Oriental region: Sri Lanka.

Unknown.

According to Krombein (1983), the female of Baeosega has no malar groove. However, a trace of a groove is present from the lower margin of the eye to the mandibular base. A minute inner tooth is also present in the claws of both female and male, but the size of tooth is remarkably small compared to Serendibula.

Figure 2. 

General habitus of Amiseginae A Nipponosega yamanei Kurzenko & Lelej, holotype ♀ B ditto, ♂ C Okinawasega eguchii Terayama ♀ D ditto, holotype ♂. Scale bars: 1.0 mm.

Holotypes. Baeosega humida: Sri Lanka ♀, “SRI LANKA: Kan. Dist./ Udawattakele Sanct./ Elevation 1800 ft./ 23–25-IX-1980”, “Collected/ on or in/ leaf litter”, “K.V. Krombein/ P.B. Karunaratne/ L. Jayawickrema/ V. Gunawardane/ P. Liyanage” “HOLOTYPE/ BAEOSEGA/ HUMIDA/ Karl V. Krombein”, “Type No./ 100454/ U.S.N.M.” (USNM); Baeosega laticeps: Sri Lanka ♀, “SRI LANKA: Kan. Dist./ Udawattakele Sanct./ 25–27-IV-1981”, “collected on or/ in leaf litter”, “K.V. Krombein/ T. Wijesinhe/ L. Jayawickrema”, “HOLOTYPE/ BAEOSEGA/ LATICEPS/ Karl V. Krombein”, “Type No./ 100455/ U.S.N.M.” (USNM). Paratypes. B. humida: Sri Lanka 1♂ (allotype), same locality as holotype, but collected at 21–22.IX.1980 (USNM); 4♀, same as above but K.V. Krombein, L. Jayawickrema, V. Gunawardane, T. Wijesinhe leg. (USNM); 4♀1♂, same locality as above, but collected at 23–25.IX.1980, K.V. Krombein, P.B. Karunaratne, L. Jayawickrema, V. Gunawardane, P. Liyanage leg. (USNM); 1♀, same locality as above, but 12–14.X.1980, K.V. Krombein, P.B. Karunaratne, L. Jayawickrema, V. Gunawardane, T. Wijesinhe leg. (USNM); 8♀, same locality as above, but 25–27.IV.1981, K.V. Krombein, T. Wijesinhe, L. Weeratunge leg. (USNM); 1♂, same locality and collectors as above, but 22.V.1981 (USNM); B. laticeps: Sri Lanka 2♀, same as locality as holotype of B. laticeps, but 12–14.X.1980, K.V. Krombein, P.B. Karunaratne, L. Jayawickrema, V. Gunawardane leg. (USNM).

The female of Baeosega humida Krombein can be distinguished from B. torrida Krombein, the other known species of Baeosega, by having the smooth metasoma. The male is similar to B. torrida, however, B. humida can be distinguished from B. torrida by the short F3 (2.7 × as long as wide). Punctures on mesepisternum are often separated with each other, but sometimes contiguous as in B. torrida. The body color of both female and male is brownish unlike B. torrida. Other diagnostic characters are as follows: (female) body length 2.3–2.7 mm; head (Figs 1A, 3A, B) black, bearing faint bronzy tint, punctate with interspaces granulated, except the costate scapal basin; malar sulcus indicated by a faint groove; occipital carina absent, only posterior margin of vertex forming corner behind ocellar triangle; mesosoma (Fig. 3C, D) dark brown to brown, part of pronotum, mesoscutum and metanotum darkened; surface punctate with interspaces granulated; (male) body length 2.3–2.7 mm; head (Fig. 4A) dorsally dark brown with face testaceous, punctate by densely located punctures; occipital carina absent; mesosoma (Fig. 4C) dark brown with mesoscutum blackish, punctate as head; postero-lateral corner of propodeum with distinctly producing angle.

Figure 3. 

Baeosega humida Krombein ♀ A holotype of B. humida, head in frontal view B ditto, dorsal view C ditto, mesosoma D holotype of B. laticeps, mesosoma. Scale bars: 0.5 mm.

Sri Lanka (Central Province, Kandy District).

According to Krombein (1983), the slender proportion of the head and mesosoma of Baeosega laticeps Krombein is the important diagnostic character separating it from B. humida Krombein. However, the body proportion can be variable to some extent. This variation is probably caused by the different shape of the host egg. Because there is no significant difference except for the proportion (slightly compressed laterally or not), B. laticeps is considered to be a junior subjective synonym of B. humida.

Figure 4. 

Baeosega humida Krombein, allotype ♂ A head in dorsal view B forewing C mesosoma. Scale bars: 0.5 mm.

Holotype. Sri Lanka ♀, “SRI LANKA: Mon. Dist./ Angunakolapelessa/ 22-28-III-1981”, “collected on or/ in leaf litter”, “K. V. Krombein/ T. Wijesinhe/ L. Weeratunge”, “HOLOTYPE/ BAEOSEGA/ TORRIDA/ Karl V. Krombein”, “Type No./ 100453/ U.S.N.M.” (hand-written) “2083468”. Paratypes. Sri Lanka 1♂ (allotype), same as holotype, but 100 m alt., 23.I.1979, MsT (USNM); 1♂, same as above (USNM).

The female of Baeosega torrida Krombein can be distinguished from B. humida Krombein by having the rugulose anterior declivity of T1 (Fig. 5C) and the strongly granulated dorsum of metasoma (Fig. 5D). Superficially, the reddish mesosoma is similar to Nipponosega females and Serendibula deraniyagalai Krombein. The male of B. torrida is similar to B. humida, however, the F3 is longer (3.5 × as long as wide) unlike B. humida. Other diagnostic characters are as follows: (female) body length 1.8–2.7 mm; head (Figs 1B, 5A, B) black, bearing faint bronzy tint, punctate with interspaces granulated; malar sulcus indicated by a faint groove; occipital carina absent; mesosoma (Figs 1B, 5C) punctate with interspaces strongly granulated; metasoma (Fig. 5D) blackish; stout silvery subdecumbent setae on mesosoma and metasoma; (male) body length 2.3–2.5 mm; head (Figs 1C, 6A, B) testaceous with dark flagellum, rarely around ocellar region brown, punctate by densely located punctures; occipital carina absent; mesosoma (Figs 1C, 6C) testaceous with mesoscutum, mesoscutellum, metanotum and dorsum of propodeum brown or rarely reddish, punctate as head; punctures on mesepisternum largely contiguous; postero-lateral corner of propodeum with weakly producing angle.

Figure 5. 

Baeosega torrida Krombein, holotype ♀ A head in frontal view B ditto, dorsal view C mesosoma D metasoma. Scale bars: 0.5 mm.

Sri Lanka (Uva Province: Monaragala District; Southern Province: Hambantota District; Central Province: Kandy District, Matale District)

Figure 6. 

Baeosega torrida Krombein ♂ A head in frontal view, paratype B ditto, dorsal view, allotype C ditto, mesosoma. Scale bars: 0.5 mm.

General characters of Nipponosega are similar to those of Baeosega and Okinawasega. The distinctive characters of Nipponosega are in the developed occipital carina in the female, the short setae on flagellum and the short pronotum in the male. More details, see the diagnosis of Baeosega.

Female. Clypeal apex not thickened; malar sulcus absent or indicated as faint track; scapal basin shallow, cross-ridged, median longitudinal smooth strip present; occipital carina present, reaching gena (Fig. 8C); eye setose; flagellum fusiform, intermediate segments broader than long, and with ventral surface flattened. Mesosoma slender, punctate or longitudinally striate; pronotum with median groove and shallow pit before lateral lobe, as long as combined length of mesoscutum, mesoscutellum and metanotum; mesoscutum with notauli and without parapsides; posterolateral corner of mesoscutum not lobate; micropterous (Figs 1D, 2A), forewing pads extending to posterior margin of mesoscutellum; mesopleuron with omaulus; scrobal sulcus lacking; metanotum triangular, longer than mesoscutellum; propodeum with long dorsal surface and a pair of recumbent teeth present, almost meeting together, dorsal posterolateral angles bluntly angulate, lateral surfaces abruptly declivous and posterior surface rounded. Hind coxa with dorsobasal carina; tarsal claws without inner tooth. Metasoma smooth.

Male. Clypeal apex not thickened; scapal basin flat, cross-ridged, median longitudinal smooth strip present; malar sulcus present; occipital carina absent (Fig. 9C); eye setose; antenna elongate, F3 2.3 × longer than wide. Mesosoma stout, dorsum punctate; pronotum with median groove and shallow pit before lateral lobe, 0.7–0.9 × as long as mesoscutum (Fig. 9E); median length of pronotum 0.4–0.5 × as long as combined length of mesoscutum, mesoscutellum and metanotum; mesoscutum with notauli; parapsidal line faintly indicated; mesopleuron without omaulus and scrobal sulcus; metanotum ca. 0.6 × as long as mesoscutellum; a pair of recumbent teeth present, slightly separated each other; propodeum with dorsal posterolateral angles rounded, posterior surface abruptly declivous; fully winged (Fig. 2B), R1 tubular, thick (Fig. 9D), not clearly differentiated from pterostigma; Rs extended by weakly curved dark streak; medial vein arising at or before cu-a. Hind coxa with dorsobasal carina; tarsal claws with one small inner tooth. Metasoma punctate with smooth interspaces.

Palaearctic region: Japan (Honshu, Shikoku, Kyushu, northern Ryukyus); Oriental region: China (Zhejiang); Thailand.

Micadina phluctainoides (Rehn, 1904) (Diapheromeridae) is considered to be the host of Nipponosega yamanei in Japan (Mita 2014).

Nipponosega kurzenkoi is closely related to N. yamanei from Japan. It can be distinguished from N. yamanei by the fully testaceous mesopleuron, whereas it is blackish in N. yamanei (Fig. 2A). Also, the frons is wider than in N. yamanei. The maximum interocular distance (measured at the lower end of the face) is 1.2 × longer than the width of frons (1.5–2.0 in N. yamanei). Other diagnostic characters are as follows: body length 3.0 mm; head black, smooth with scattered punctures; lateral ocelli well separated from the inner margin of eye; mesosoma largely testaceous with mesoscutum and mesoscutellum black; pronotum smooth with scattered punctures; legs yellow; metasoma dark brown. Male is unknown.

China (Zhejiang).

Although the body color could be variable to some extent, no specimen of N. yamanei with completely testaceous mesopleuron has been found; a closely related species showing different distribution. The morphology of N. kurzenkoi should be evaluated in more detail to discuss their identification. However, diagnostic characters shown above do not overlap with those of N. yamanei. In the original description of N. kurzenkoi Xu et al., 2003, the evaluation of POD is different from the POD (= POL herein) used in Nagase (1995). The POD sensu Xu et al. (2003) is correspond to OOL herein.

Holotype. Thailand ♀ (THNHM-I-23985), “[NW Thailand] / Tak prov., / Umphang WS, / nr Pha Lueat stn.”, “28. i 2015 / Sk. Yamane leg. / 390 m alt.; leaf /& surface soil”, “Sk Yamane Collection” (THNHM).

Nipponosega lineata sp. nov. is readily distinguished from other Nipponosega species by the longitudinally costate pronotum (Fig. 7D). Other characters useful to distinguish from other species are as follows: body length 2.8 mm; head black, punctate with interspaces smooth, posterior margin of vertex longitudinally costate (Fig. 7D); maximum interocular distance 2.9 × longer than width of frons; lateral ocelli almost touching the inner margin of eye; malar sulcus indicated as a faint track (Fig. 7C); outer orbit of eye with a row of punctures; occipital carina present (Fig. 7B, D), reaching lower gena; antenna blackish with scape and F1 testaceous; mesosoma reddish but dorsum largely black; mesoscutum and mesoscutellum punctate; legs brownish; metasoma dark brown, smooth. Male is unknown.

Figure 7. 

Nipponosega lineata sp. nov., holotype ♀ A head in frontal view B ditto, dorsal view C ditto, lateral view D vertex and mesosoma. Scale bars: 0.5 mm.

Holotype female. Body length 2.81 mm. Head (Fig. 7A–C) punctate except scapal basin and posterior margin of vertex, as long as wide in dorsal view, 0.82 × as wide as deep in frontal view; punctures 0.5–1.0 × MOD, 0.5–2.0, 2.0–3.0, and, 0.5–1.0 punctures diameter apart on frons, ocellar region and vertex, respectively; interspaces among punctures smooth; scapal basin moderately excavated, transversely costate by fine grooves, upper part with short median unsculptured line; malar sulcus indicated as faint track; frons narrow, shortest distance between eyes 0.23 × head width; maximum interocular distance 2.9 × as long as narrowest width of frons; MS 0.23 × as long as eye height; outer orbit of eye with a row of deep punctures; ocellar triangle acute, lateral ocelli almost touching inner margin of eye; OL 1.3, OPL 2.2, POL 1.0, OOL 0.2, MOD 0.3; posterior margin of vertex longitudinally costate; occipital carina present, reaching gena. Clypeus thickened. Mandible without inner tooth, cylindrical. Antenna stout, F4–F9 wider than long; length (width) of F1 to F4 following ratio: 5.8 (1.5): 1.8 (1.7): 1.8 (1.8): 1.5 (2.0).

Pronotum (Fig. 7D) longitudinally costate by fine grooves except anterior narrow region smooth with several punctures; medial longitudinal line reaching 3/4 of pronotum; length of pronotum measured mesad 0.89 × as long as wide, 1.6 × mesoscutum plus mesoscutellum. Mesoscutum roughly punctate-reticulate: punctures as long as or slightly smaller than MOD; notauli complete, diverging anteriorly. Mesoscutellum punctate as mesoscutum, 0.59 × longer than mesoscutum. Mesopleuron punctate with smooth interspaces: punctures as long as MOD. Metanotum triangular, as long as mesoscutellum mesad, punctate. Propodeum (Fig. 7D) with postero-lateral corner rounded; dorsal surface long, smooth, transversely rugose; posterior surface transversely rugose; lateral surface obliquely rugose; metapleural region smooth but behind meso-metapleural suture costate. Middle and hind coxae transversely costate.

Metasoma smooth, covered with sparse setae; setae 2.5 × MOD.

Color. Head black. Antenna basally testaceous with distal apex of scape and pedicel dark brown, F2–F10 black. Mandible brown. Mesosoma reddish but following parts blackish: dorsal surface of pronotum, anterior 2/3 of propleuron, mesoscutum, mesoscutellum, ventral surface of mesepisternum, median enclosure of metanotum, postero-dorsal surface of propodeum. Tegula and wings brown. Coxae whitish with postero-dorsal dark spot; trochanters testaceous; fore femur brown with basal and distal parts testaceous; middle and hind femora brown with basal parts testaceous; tibiae brown with basal parts of fore and hind tibiae testaceous; tarsi testaceous with fore and hind tarsi basally brownish. Metasoma dark brown with anterior surface of T1 and S1 paler.

Thailand (Tak Province).

The specific name derives from the Latin word lineata, referring to the presence of striae on the pronotum.

The holotype was collected from the leaf litter.

Holotypes. Nipponosega yamanei: Japan – Honshu ♀, “JAPAN Ibaraki-ken / Shishitsuka Ohike / Tsuchiura City / Lelej 17 viii 1993”, “NSMT-HYM / 62329”, “Holotypus ♀ / Nipponosega / yamanei / Kurzenko et Lelej”(NSMT); Nipponosega kantoensis: Japan ♀, “Tonbo-Park / Sueno, Yorii / Saitama / 11. VIII. 1991 / T. Nambu leg”, “NSMT-HYM / 62328”, “HOLOTYPE / Nipponosega / kantoensis / H. Nagase 1995”(NSMT).

Other materials. Japan – Honshu 1♀2♂, Ogawa (600–800 m alt.), Kitaibaraki, Ibaraki Pref., 14–28.VIII.2002, MsT, H. Goto et al. leg. (ELKU); 1♂, same data, but (FFPRI); 3♀, Okami, Satomi-mura, Ibaraki Pref., 9–24.IX.2003, MsT, S. Makino et al. leg. (FFPRI); 1♀, Fujisawa-shi, Kanagawa Pref., 24–25.IX.2009, pit fall trap, T. Shimada leg. (ELKU); 1♂, Yawata (650 m alt.), Asahi, Aichi Pref., 29.VII–11.VIII.1998, MsT, A. Hanai, K. Yamagishi leg. (ELMU); 1♀, Yawata Shrine (400 m alt.), Asahi, Aichi Pref., 12–21.VIII.1998, MsT, M. Ozawa leg. (ELMU); 1♀, Kurisu, Inuyama, Aichi Pref., 19–25.VII.1996, EmT, T. Mabuchi leg.; 1♀, Mt. Sanage, Aichi Pref., 7–13.VIII.1992, EmT, K. Shima leg. (ELMU); 2♂, Takiwaki, Toyota, Aichi Pref., 8–14.VII.2002, MsT, Y. Kurahashi Leg. (ELMU); 1♀, same data, but 19–25.VIII.2002; 1♀, Tougoku, Seto, Aichi Pref., 10–16.VIII.1997, MsT, M. Kenmotsu leg. (ELMU); 1♀, Kurotani, Y., Hiroshima Pref., 7–13.VIII.1995, YPT, A. Morimoto leg. (ELMU); – Shikoku 1♀, Mt. Takanawa, Matsuyama, Ehime Pref., 26.VII.2017, K. Kuroda leg. (ELKU); 1♀, Jikiba-machi, Matsuyama-shi, Ehime Pref., 25.VII.2017, shifting, Y. Hisasue leg. (ELKU); – Kyushu 1♀, Mt. Kaya, Itoshima-shi, Fukuoka Pref., 2.X.2018, shifting, S. Inoue leg. (ELKU); 1♀, same locality as above, but Mt. Iwara, 8.IX.2019, K. Nishiya leg. (ELKU); 1♀, Hikosan Biological Laboratory, Kyushu University, Mt. Hiko (670 m alt.), Fukuoka Pref., 2.X.1968, MsT, K. Takeno leg.; 1♀, same data but 28–29.IX.1968; 1♀, same data but 15.X.1968; 1♂, same data but 4.IX.1970; 1♀, Mt. Hiko (700 m alt.), Fukuoka Pref., 20–28.VIII.2008, MsT, T. Mita, S. Sato leg. (ELKU); 1♀, Gokasho Plateau (860 m alt.), Takachiho-cho, Miyazaki Pref., 22.VIII.2015, Sk. Yamane leg. (ELKU); 2♀, same data but 23.VIII.2015; 1♀, Mt. Tatera, Tsushima Isl., Nagasaki Pref., 25–26. IX. 2015, YPT, Y. Hisasue leg. (ELKU); 1♀, same as above, but Mt. Shimizu, Izuhara-machi, 19.X.2019, T. Hashizume leg. (ELKU); – Ryukyus 2♀, Kurio, Yakushima Isl., 13.VII.1970, K. Yamagishi leg. (ELMU); 1♂, same island, but Miyanoura, 21.VI–11.VII.1999, MsT, T. Murota (A. Hanai) leg. (ELMU).

In the genus Nipponosega, N. yamanei Kurzenko & Lelej is the only species known by both female and male. The female is similar to N. kurzenkoi in China. They can be distinguished by the body coloration and the width of frons. The mesopleuron is blackish in N. yamanei (Fig. 2A), whereas it is fully testaceous in N. kurzenkoi. The frons is narrower, the maximum interocular distance is 1.5–2.0 × longer than the width of frons in full face view (1.2 in N. kurzenkoi). Other diagnostic characters of the female are as follows: body length 2.5–3.9 mm; head black, smooth with scattered punctures; posterior ocelli well separated from the inner margin of eye; pronotum reddish, smooth with scattered punctures; mesoscutum, mesoscutellum, anterior part of mesepisternum and often propodeum black; legs yellow; metasoma dark brown. The body length of the male is 3.2–3.8 mm. The male of other species of Nipponosega is unknown. Compared to other genera found in Japan, the male of N. yamanei can be distinguished by the head without occipital carina and impunctate welt; the body black, without metallic reflection; and the forewing with R1 thick, not clearly separated from pterostigma.

Female. Body length 2.5–3.9 mm. Head (Fig. 8A–D) punctate except scapal basin, 0.65–0.81 × as long as wide in dorsal view, 0.89–1.18 × as wide as deep in frontal view; punctures 0.3–0.5 × diameter of median ocellus, 0.3–1.0 punctures diameter apart on frons, 1.0–3.0 punctures diameter apart on ocellar region and vertex; interspaces among punctures smooth; scapal basin moderately excavated to almost flat, transversely costate by fine grooves, with median unsculptured line; malar sulcus absent; narrowest width of frons 0.24–0.33 × head width; maximum interocular distance 1.5–2.0 × as long as narrowest width of frons; MS 0.24–0.34 × as long as eye height; ocellar triangle variable, OL 0.7–1.6 × as long as POL, OL 0.8–1.2, OPL 2.0–2.5, POL 0.5–1.0, OOL 0.3–0.6, MOD 0.4–0.5; occipital carina present, reaching lower gena (Fig. 8C), occasionally present only behind ocellar triangle, only upper gena, or rarely almost invisible. Clypeus not thickened, with thin square transparent lobe. Mandible without inner tooth. Antenna stout, F2–F7 wider than long; length (width) of F1–F4 following ratio: 2.7–3.2 (1.0–1.2): 0.7–1.0 (1.0–1.3): 0.9–1.0 (1.1–1.3): 1.0 (1.1–1.4).

Figure 8. 

Nipponosega yamanei Kurzenko & Lelej ♀ A holotype of N. yamanei, head in frontal view B ditto, dorsal view C female from Aichi, gena (arrow indicates occipital carina) D holotype of N. kantoensis Nagase, head in dorsal view E holotype of N. yamanei, mesosoma. Scale bars: 0.5 mm.

Pronotum (Fig. 8E) punctate with faintly coriaceous interspace; punctures slightly smaller than those on frons, 0.3–0.4 MOD, 3–5 PD apart; medial longitudinal line reaching 2/3 of pronotum, rarely groove fully developed; median length of pronotum 0.72–0.86 × as long as wide, 1.2–1.6 × mesoscutum plus mesoscutellum. Mesoscutum 0.43–0.50 × longer than pronotum, sculptured as vertex; notauli complete, diverging anteriorly. Mesoscutellum 0.5–0.75 × longer than mesoscutum, punctate as mesoscutum with interspaces faintly transversely rugulose. Mesopleuron sculptured as pronotum. Metanotum triangular, median length 0.67–0.87 × mesoscutellum, with shallow punctures. Propodeum with postero-lateral corner forming blunt angle (Fig. 8E), angle sometimes weak; dorsal surface of propodeum short, medially smooth, laterally rugose, sometimes irregularly reticulate; transverse or arched carina present behind; sometimes lateral carina present; posterior surface transversely costate with median longitudinal carina, sometimes laterally reticulate; lateral surface faintly costate with carinae antero-dorsally effaced; metapleural region polished or faintly transversely rugose. Middle and hind coxae transversely costate.

Metasoma faintly coriaceous, sparsely covered with setae; length of setae 2 MOD.

Color. Head black. Antenna basally testaceous, F2–F10 dark brown, sometimes dorsal half of F2 testaceous. Mandible testaceous with reddish teeth. Mesosoma with prothorax, posterior half of mesopleuron and lateral surface of propodeum reddish to light brownish, remainder of mesothorax, metanotum and dorsal to posterior surface of propodeum brownish to blackish; dorsum of pronotum blackish in the female from Mt. Takanawa (Ehime Pref.); metanotum and propodeum sometimes paler especially in smaller specimens. Tegulae and wings testaceous to brown. Legs testaceous, sometimes femora and tibiae brownish. Metasoma brown to dark brown, rarely blackish, usually anterior surface of T1 and sterna paler.

Male. Body length 3.2–3.8 mm. Head (Fig. 9A–C) densely punctate except scapal basin, 0.5–0.57 × as long as wide in dorsal view, 1.16–1.46 × as wide as deep in frontal view; punctures 0.2–0.3 MOD, almost contiguous to 0.3 puncture diameter apart each; scapal basin excavated, transversely rugose with median unsculptured line; MS 0.3–0.4 × as long as eye height; narrowest width of frons 0.6–0.7 × head width; ocellar triangle obtuse, OL 0.5–0.6 × as long as POL, OL 0.8, OPL 2.0–2.8, POL 1.5, OOL 0.5–0.6, MOD 0.8–1.0. Clypeus not thickened, with thin transparent lamella. Mandible distally truncate. Antenna cylindrical, flagellum densely covered with setae; length of setae ca. 0.6 × flagellomere diameter; length (width) of F1 to F4 following ratio: 3.3–4.0 (0.8–1.0): 1.8–2.5 (0.8–1.1): 1.8–2.3 (0.8–1.0): 1.8–2.0 (0.8–1.0).

Figure 9. 

Nipponosega yamanei Kurzenko & Lelej ♂ A Head in frontal view B ditto, lateral view C ditto, dorsal view D forewing, pterostigma and R1 E mesosoma. Scale bars: 0.5 mm.

Pronotum (Fig. 9E) densely punctate as vertex; medial longitudinal groove present on posterior 3/5; median length of pronotum 0.46–0.58 × as long as wide, 0.7–0.9 × mesoscutum. Mesoscutum densely punctate as vertex; on posterior half interspaces faintly granulate; notauli complete, diverging anteriorly. Mesoscutellum punctate as mesoscutum, 0.45–0.63 × longer than mesoscutum. Mesopleuron punctate with polished interspaces; punctures slightly larger than those on pronotum, 0.3–1.5 puncture diameter apart; surface near pleural suture polished, without puncture. Metanotum with sparse punctures, median length 0.52–0.68 × mesoscutellum; punctures 1–3 puncture diameter apart. Propodeum postero-laterally forming dully corner, without teeth or distinct angle; dorsal surface more or less rugose, sometimes only median longitudinal carina present; transverse carina present between dorsal and posterior surface; posterior surface finely reticulate rugose with median longitudinal carina; lateral surface with ventral 2/3 finely reticulate, dorsal 1/3 smooth; metapleural region polished, more or less rugose and longitudinally excavated behind pleural suture. R1 tubular, thick, not clearly distinguished from pterostigma (Fig. 9D); Rs extended by weakly curved dark streak; medial vein arising at or before cu-a. Legs with surface of coxae smooth; hind coxa with dorsobasal carina; tarsal claws with one small inner tooth.

Dorsal surface of terga and sterna with fine punctures; punctures on T1 and T2 1–2 puncture diameters apart, with interspaces polished.

Color. Head, mesosoma and metasoma black but anterior polished surface of T1 brownish, lateral surface of T1, T2 brown. Antenna with scape testaceous, flagellomere dark brown to brown, distally slightly paler. Mandible testaceous with apex reddish. Maxillary and labial palpus testaceous. Tegula brown. Wings faintly tinged with brown; veins brown. Legs testaceous with hind tibia dark brown.

Japan (Honshu; Shikoku; Kyushu; Tsushima Isl.; Yakushima Isl.).

Diapheromeridae: Micadina phluctainoides (Rehn, 1904).

Although ocelli and head proportions of the female have been considered useful for species classification (Nagase 1995), they actually show great variation. The holotypes of N. yamanei (Fig. 8B) and N. kantoensis (Fig. 8D) are examples of the two extremes and intermediate females are more frequently found. This makes it difficult to distinguish between the two types.

Males of N. yamanei were only obtained by Malaise traps and occasionally they were collected together with Cladobethylus japonicus Kimsey, 1997. The males of both species have been unknown; however, the morphological characters of the trapped males were close to those of Baeosega. As Cladobethylus is a genus showing little sexual dimorphism (Kimsey 2019), they are considered as Nipponosega. Compared to the abundance of the female, the male of N. yamanei is rarely collected. Some females were found above the ground surface (1 m or more) (Nagase 1995; Tomura 2020), but in fact they are more likely on the ground floor or in the leaf litter. Multiple females were obtained in Malaise traps, suggesting that females actively walk around the forest floor and climb understory vegetation. Females were observed to carry the host eggs for oviposition (Y. Hisasue, personal communication).

General characters of Okinawasega are similar to those of Baeosega and Nipponosega; however, there are some distinctive differences, e.g., the deep malar sulcus in the female, the elongated linear R1 in the male. For more details, see the diagnosis of Baeosega.

Female. Clypeal apex not thickened; malar sulcus present (Fig. 10D); scapal basin shallow, cross-ridged, median longitudinal carina present; occipital carina absent but posterior margin of vertex forming distinct corner behind ocellar triangle; eye setose; flagellum fusiform, intermediate segments broader than long, and with ventral surface flattened. Mesosoma slender, punctate by dense punctures; pronotum with median groove and shallow pit before lateral lobe, as long as combined length of mesoscutum, mesoscutellum and metanotum; mesoscutum with notauli and without parapsides; posterolateral corner of mesoscutum not lobate; micropterous (Fig. 2C), forewing pads extending to posterior margin of mesoscutellum; mesopleuron with omaulus, without scrobal sulcus; metanotum triangular and small, slightly shorter than mesoscutellum; propodeum with long dorsal surface and a pair of recumbent teeth present, almost meeting together, dorsal posterolateral angles bluntly angulate, lateral and posterior surfaces abruptly declivous. Hind coxa with dorsobasal carina; tarsal claws without inner tooth. Metasoma smooth.

Figure 10. 

Okinawasega eguchii Terayama ♀ A head in frontal view B ditto, dorsal view C ditto, lateral view D ditto, malar space (arrow indicates malar sulcus) E mesosoma. Scale bars: 0.5 mm.

Male. Clypeal apex not thickened; scapal basin flat or weakly excavated, cross-ridged; malar sulcus present; occipital carina absent but posterior corner of vertex forming distinct corner behind ocellar triangle, occasionally trace of occipital carina present on upper gena; eye setose; antenna elongate, F3 3.5–4.3 × longer than wide. Mesosoma slender, dorsum punctate by dense punctures; pronotum with median groove and shallow pit before lateral lobe; pronotum as long as mesoscutum, 2/3 of combined length of mesoscutum, mesoscutellum; mesoscutum with notauli; parapsidal line faintly indicated; mesopleuron without omaulus and scrobal sulcus; metanotum approximately half mesoscutellum (Fig. 11E); a pair of recumbent teeth present, meeting or almost meeting together; propodeum with dorsal posterolateral angles bluntly angulate, posterior surface abruptly declivous; fully winged (Fig. 2D), pterostigma normal, with linear extension of R1 indicated, long (Fig. 11D, arrow); Rs extended by weakly curved dark streak; medial vein arising before cu-a. Hind coxa with dorsobasal carina; tarsal claws without inner tooth. Metasoma sparsely punctate with smooth interspaces.

Figure 11. 

Okinawasega eguchii Terayama ♂ A head in frontal view B ditto, dorsal view C ditto, lateral view D forewing E mesosoma. Scale bars: 0.5 mm.

Oriental region: Japan (Yaeyama Islands, southern Ryukyus).

Unknown.

The previous record of Baeosega in southern Ryukyus (Kimsey 1995) should probably be attributed to Okinawasega.

Holotype. Japan – Ryukyus ♂, “Holotype”, “Okinawasega eguchii Terayama, 1999”, ”Genotype Okinawasega Terayama, 1999”, “Iriomote-jima, Yaeyama Is., Okinawa Pref.”, “Japan”, “1. XI. 1995, K. Eguchi leg.”, “951101, Iriomote Is., Q1” (NMHAH).

Other materials. Japan – Ryukyus 1♂, Shiramizu, Ishigaki Isl., 9.V.2004, T. Mita leg. (ELKU); 7♂, same data, but 10.V.2004 (ELKU); 4♂, same as above, but Mt. Omoto-dake, 15.V.2004, T. Tsuru leg. (ELKU); 3♂, Aira-gawa, Iriomote Isl., 8–12.X.2004, FIT, T. Ishikawa leg. (ELKU); 1♂, same data, but 14.V.2014, T. Mita leg. (ELKU); 17♂, same data, but 24–26.VI.2016, YPT, K. Komeda leg. (ELKU); 1♀24♂, same data, but 22–25.VI.2016 (ELKU); 1♀, same data, but 4.VII.2017, T. Kawano leg. (ELKU); 1♀, same island, but Mt. Tedou, 3.X.2017, K. Narita leg. (ELKU).

Conspicuous species in the southern Ryukyus (Japan). The female is blackish and covered with long setae, the body length is 3.5–3.6 mm. The male has long antennae and reddish body, the body length is 3.2–3.8 mm.

Female. Body length 3.5–3.6 mm. Head (Fig. 10A–D) densely punctate except scapal basin, 0.65–0.70 × as long as wide in dorsal view, 0.95–1.00 × as wide as deep in frontal view; punctures 0.3 MOD, almost contiguous but part of frons 1.0 puncture diameter apart each; scapal basin weakly excavated, transversely costate by fine grooves, with median unsculptured line; interspaces among punctures smooth; malar sulcus present (Fig. 10D); narrowest width of frons 0.3 × head width; MS 0.3 × as long as eye height; ocellar triangle acute, OL 1.0–1.2, OPL 2.3, POL 0.8–0.9, OOL 0.4–0.5, MOD 0.5–0.7; occipital carina absent but posterior margin of vertex forming distinct corner behind ocellar triangle. Clypeus not distinctly thickened, with thin square transparent lobe. Mandible without inner tooth. Antenna stout, F2–F9 wider than long; length (width) of F1 to F4 following ratio: 2.6–2.7 (1.1–1.2): 1.0 (1.3–1.4): 1.0 (1.4–1.5): 1.0 (1.5–1.7).

Pronotum (Fig. 10E) covered with densely located punctures, punctures same with those on head in size but deeper, slightly smaller mesad, somewhat longitudinally contiguous; medial longitudinal groove present on posterior 1/3 but polished strip leaching ca. 2/3; length of pronotum mesad 0.7–0.8 × as long as wide, 1.1–1.3 × mesoscutum plus mesoscutellum. Mesoscutum roughly puncto-reticulate, punctures 0.7 × larger than those on pronotum; notauli complete, diverging anteriorly. Mesoscutellum punctate as mesoscutum, 0.5–0.6 × longer than mesoscutum. Mesopleuron densely punctate; punctures larger, 0.7 MOD. Metanotum triangular, 0.7–0.9 × mesoscutellum mesad, punctate by shallow punctures. Propodeum with dorsal, posterior and lateral surface transversely rugose by obscure striae; median longitudinal carina present; metapleural region polished, finely rugose behind meso-metapleural suture, carinated above metacoxa; postero-lateral corner forming dully angle.

Metasoma smooth, sparsely covered with long setae; setae 3 × longer than MOD.

Color. Head, mesosoma and metasoma black but lateral surface of T1 brown, S1 dark brown. Antenna black but scape dark brown, pedicel and F1 brown. Mandible pale brown with apex black. Maxillary and labial palpi brown. Tegula and wings dark brown. Coxae and trochanters testaceous; remainder of fore and middle legs brown; remainder of hind leg dark brown.

Male. Body length 3.6–3.7 mm. Head (Fig. 11A–C) densely punctate except scapal basin, 0.59–0.66 × as long as wide in dorsal view, 1.14–1.21 × as wide as deep in frontal view; punctures 0.2–0.3 MOD, interspaces ca. 0.3–1.0 puncture diameter; scapal basin faintly excavated, transversely rugose with median unsculptured line; MS 0.4–0.5 × as long as eye height; narrowest width of frons 0.63–0.76 × head width; ocellar triangle obtuse, OL 0.8–1.0, OPL 2.3–3.0, POL 1.3–1.5, OOL 0.05, MOD 0.8; occipital carina absent but posterior corner of vertex forming distinct corner behind ocellar triangle, occasionally trace of occipital carina present on upper gena. Clypeus thin. Mandible distally truncate. Antenna cylindrical, flagellum densely covered with long setae; length of setae ca. 0.8 × flagellomere diameter; length (width) of F1 to F4 following ratio: 4.3–4.7 (0.7–1.0): 3.0 (0.7–1.0): 3.0 (0.7–0.8): 2.8–3.0 (0.7–0.8).

Pronotum (Fig. 11E) punctate as vertex; medial longitudinal groove variable, present posterior 1/3 to reaching anterior margin of disc; length of pronotum mesad 0.7–0.8 × as long as wide, 0.9–1.1 × mesoscutum. Mesoscutum punctate as head, but punctures slightly smaller than those on vertex, 0.2–0.5 puncture diameter apart; notauli complete, diverging anteriorly. Mesoscutellum scattered with shallow punctures with polished interspace, 0.50–0.58 × longer than mesoscutum. Mesopleuron punctate with polished interspace; punctures slightly larger than those on pronotum, 0.3–1.0 puncture diameter apart; subalar fossa indicated by continuous row of punctures or groove, rarely absent; usually surface near pleural suture polished, without punctures. Metanotum 0.48–0.60 × mesoscutellum, punctate as mesoscutellum. Propodeum (Fig. 11E) postero-laterally forming dull corner; dorsal surface reticulate-rugose with median and usually two pairs of longitudinal carinae present; transverse carina present between dorsal and posterior surface; posterior and lateral surface reticulate-rugose; median longitudinal carina present on posterior surface; metapleural region polished, more or less rugose and longitudinally excavated behind meso-metapleural suture, carinated above hind coxa. Pterostigma narrow, with linear extension of R1 indicated, long (Fig. 11D, arrow); Rs extended by weakly curved dark streak; medial vein arising before cu-a. Hind coxa with dorsobasal carina; tarsal claws without inner tooth.

Color. Head black. Antenna dark brown, rarely blackish. Mandible testaceous with apex dark brown. Maxillary and labial palpus testaceous. Mesosoma mostly reddish to dark reddish except mesoscutum black, tegula brown, propodeum with posterior surface darker, rarely entirely blackish; rarely dorsum of mesosoma blackish. Wings faintly tinged with brown; veins brown, rarely dark brown. Legs testaceous. Metasoma blackish except anterior polished surface of T1 brownish.

Japan: Yaeyama Islands, Southern Ryukyus (Ishigaki Isl., Iriomote Isl.)

No species in Baeosega-related genera are known from Ishigaki-jima and Iriomote-jima except for the male of Okinawasega eguchii Terayama. The newly found female was clearly related to Baeosega, and was therefore assigned to Okinawasega. Compared to males, females are seldom collected. The females actively walk on the ground surface and sometimes leap a small distance.