Lasioglossum (Evylaeus) yonaguniense Murao

Murao, Ryuki, Tadauchi, Osamu, Goubara, Masashi & Maeta, Yasuo, 2010, Taxonomy of the carinaless group of Lasioglossum (Evylaeus) (Hymenoptera, Halictidae) from the Ryukyu Islands, Japan, with description of seven new species, Zootaxa 2669, pp. 1-33 : 23-26

Lasioglossum (Evylaeus) yonaguniense Murao sp. nov.

( Figs. 13 , 14 )

Description. Female. Body length 4.3–5.5 mm, wing length 4.0–5.0 mm (n= 6).

Color. Tegula brown translucent. Posterior margins of metasomal terga narrowly yellowish brown or reddish brown translucent.

Pilosity. T1 ( Fig. 14 C) medially with moderately dense simple and short hairs. Metasomal terga with neither basal hair bands nor apical fimbriae.

Structure. Head wider than long; head length/width ratio 0.90–0.92 (n= 7). Interocellar distance subequal to ocellocular distance. Frons and paraocular area dull, reticulate-punctate. Supraclypeal area ( Fig. 13 B) dull, with dense PP; IS with distinct tessellation. Clypeal length 1.2x distance between lower rim of antennal socket and upper margin of clypeus, with dense PP on upper half, and with sparse larger shallow PP on lower half; IS with distinct tessellation on upper half, and without tessellation on lower half. Basal area of labrum 2.7x as wide as long; lateral projections of distal process small; keel of distal process moderately broad, apically pointed in frontal view. Scape length 0.6–0.7 mm (n= 6). Mesoscutum ( Fig. 13 C, D) dull, with dense PP and IS with distinct tessellation on the entire surface. Mesoscutellal IS with very weak tessellation or smooth on the entire surface, other sculpture similar to mesoscutum. Mesepisternum ( Fig. 13 F) shiny, with moderately dense PP and IS smooth on upper area, and with coarse rugulae on lower area. Propodeal dorsum ( Fig. 13 O) 0.7x mesoscutellum, and as long as metanotum, with longitudinal ridges on the entire surface, but sometimes with irregular sinuate ridges only on dorsomedial area; dorsomedial ridges long, attaining to posterior margin; propodeal side with weak rugulae; shield with distinct tessellation. Inner hind tibial spur ( Fig. 13 P) with 3–4 teeth (n= 7). T1 ( Fig. 14 C) without lineolation on the entire surface, and medially with moderately dense obscure PP. T2 basally and posteriorly with weak lineolation, medially without lineolation. T3–T4 similar lineolation with T2 on the entire surface.

Male. As in female except as follows. Body length 4.8–5.9 mm, wing length 4.1–4.4 mm (n= 3).

Color. Tegula yellowish brown translucent.

Pilosity. T1 ( Fig. 14 D) medially with moderately dense simple and short hairs. S4–S5 posterolaterally with fine branched hairs, moderately dense and long (as in Fig. 6 B).

Structure. Head length/width ratio 0.87–0.91 (n= 5). Clypeal length 1.7x distance between lower rim of antennal socket and upper margin of clypeus; with moderately dense shallow PP on the entire surface. IS nearly smooth on the entire surface. Basal area of labrum 3.4x as wide as long; basal elevation slightly developed; distal process absent. Scape length 0.4–0.5 mm (n= 4). Mesoscutal IS smooth on the entire surface. Mesepisternum with sparse PP on upper area, moderately dense shallow PP on lower area. Propodeal dorsum ( Fig. 13 M) 0.8x mesoscutellum, and 1.4x metanotum; dorsomedially with ridges on basal half, and nearly smooth apical half; lateral slope and shield smooth. Basitibial plate of hind legs without carina marginally. T2 posteriorly with very weak lineolation or without lineolation on the entire surface. T3–T4 similar lineolation with T2 on the entire surface. S7–S8 ( Fig. 14 H): S7 with narrow median process; S8 without median process. Genitalia as in Fig. 14 E–G. Gonobasal ventral arm ring-shaped, and not connected to each other at apical ends; bottom nearly flat. Gonocoxite smooth in dorsal view. Gonostylus truncate apically in lateral view, with sparse and short hairs on outer margin on dorsal view. Retrorse lobe ( Fig. 14 G) long, rounded apically, and with moderately dense short hairs on its surface.

Remarks. Within the sexstrigatum -group, this new species is similar to Lasioglossum (Evylaeus) donanense sp. nov. from the southern Ryukyus and L. (E.) urumaense sp. nov. from the central Ryukyus. For the differences among the species, see the key. So far as the first author surveyed the type locality, this species was found in the same habitat as L. (E.) donanense .

Etymology. The specific name is derived from the type locality, the Yonaguni-jima.

Distribution. Japan (southern Ryukyus: Yonaguni-jima).

Flight records. Female: March to May. Male: April to May.

Flower records. Rosaceae : Rhaphiolepis indica var. umbellate .

Type material. Holotype (Type No. ELKU 3309): female, Mantabaru, Yonaguni-jima, Okinawa Pref., Ryukyus, JAPAN, 20. iii. 2005 (R. Murao leg., RMPC). Paratypes: [Ryukyus: JAPAN] Yonaguni-jima, Okinawa Pref.: 4 females, same locality as the holotype, 20. iii. 2005 (R. Murao, RMPC), 21. iii. 2005 (R. Murao, RMPC); 1 female, Mt. Urabu-dake, 20. iii. 2005 (R. Murao, RMPC); 1 female and 1 male, 30. v. 2003 (T. Mita, RMPC); 1 male, same locality as the holotype, 29. iv. 2004 (T. Mita, RMPC); 1 male, Mt. Kurabudake, 31. v. 2003 (T. Mita, RMPC); 2 males, Sonai, 27. v. 1983 (Y. Haneda, SCMH), 31. v. 2003 (T. Mita, RMPC).

Type depository. The type series are deposited in ELKU.

Figures

FIGURE 6. Lasioglossum (Evylaeus) canaliculatum Murao, sp. nov. A, C: holotype, female. B, D, E – H: paratype, male. A: head in frontal view. B: metasomal sterna. C, D: first metasomal tergum (left half, sculpture; right half, hair pattern). E – G: male genitalia (E: left, ventral view; right, dorsal view. F: lateral view. G: retrorse lobe). H: seventh and eighth metasomal sterna. Scale bars: A, B, C, D, 1 mm; E, F, H, 0.2 mm; G, 0.1 mm.

FIGURE 13. Lasioglossum (Evylaeus) yonaguniense Murao, sp. nov. A – F: holotype, female. N – P: paratype, female. G – M, Q: male, paratype. A, G: lateral habitus. B, H: lower face. C, I: mesoscutum. D, J: sculpture on mesoscutum. E, K: mesoscutellum. F, L: mesepisternum. M, O: propodeal dorsum. N, Q: labrum. P: inner hind tibial spur. Scale bars: O, 0.5 mm; N, 0.25 mm; P, Q, 0.2 mm.

FIGURE 14. Lasioglossum (Evylaeus) yonaguniense Murao, sp. nov. A, C: holotype, female. B, D, E – H: paratype, male. A, B: head in frontal view (stippled area: yellow coloration). C, D: first metasomal tergum (left half, sculpture; right half, hair pattern). E – G: male genitalia (E: left, ventral view; right, dorsal view. F: lateral view. G: retrorse lobe). H: seventh and eighth metasomal sterna. Scale bars: A – D, 1 mm; E, F, H, 0.2 mm; G, 0.1 mm.