Lasioglossum (Dialictus) viridellum (Cockerell, 1931)

Murao, Ryuki, Tadauchi, Osamu & Lee, Heung-Sik, 2015, Synopsis of Lasioglossum (Dialictus) Robertson, 1902 (Hymenoptera, Apoidea, Halictidae) in Japan, the Korean Peninsula and Taiwan, European Journal of Taxonomy 137, pp. 1-50 : 9-10

Lasioglossum (Dialictus) viridellum (Cockerell, 1931)

Figs 1 , 2 A–E, 3B

Halictus (Chloralictus) viridellus Cockerell, 1931: 14 (holotype: American Museum of Natural History, New York, USA, ♀; type locality: Shanghai, China).

Halictus (Chloralictus) viridellus – Hirashima 1957: 24. Lasioglossum (Evylaeus) viridellum – Ebmer 1978: 312–313 (♂). — Ebmer 1996: 283–284. — Ebmer 2006: 568.

Evylaeus (Aerathalictus) viridellus – Pesenko, 2007a: 27. — Pesenko 2007b: 85 (in key), 97 (in key), 114.

Diagnosis

This species is closely similar to Lasioglossum angaricum (Cockerell, 1937) and L. pseudannulipes (Blüthgen, 1925) , as stated above. It is separated from L. angaricum by the disc of male sterna having sparse and uniform hairs. In contrast, in L. angaricum , the male S3–S5 are medially bare, laterally with tufts of long dense erect hairs ( Pesenko 2007b).

Material examined

SOUTH KOREA: Gangwon-do: 2 ♀♀, 2 ♂♂, Hong Cheon, 5–6 Jun. 1984 (K. Morimoto, ELKU); Jejudo, Jeju Is.: 11 ♀♀, Sanisu-dong Namjeju-gun, 23 Apr. 1997 (O. Tadauchi, ELKU); 1 ♀, Pijarim Forests Pukcheju-gun, 24 Apr. 1997 (O. Tadauchi, ELKU); 2 ♀♀, Kwangpyong-ri Namjeju-gun, 23 Apr. 1997 (O. Tadauchi, ELKU).

RUSSIA: 1 ♂, Primorsky Cray, 20 km SE of Spassk forest (label in Russian), 17 Jul. 1995 (Belokobylsky leg., ZISP).

Additional description

LABRUM ( Fig. 1 C–D). Basal area approximately 2.0 × as wide as long in female; basal elevation moderately developed in both sexes, depressed centrally in male; distal process of female slender, nearly as long as basal area, and without lateral projection, that of male absent; keel of distal process narrow, apically pointed; labral fimbria acutely pointed at apex in both sexes. S7–S8 ( Fig. 2E ): S7 with moderately long, apex exceeding S8; S8 without median process.

MALE GENITALIA ( Fig. 2 A–D). Gonobase flat at bottom, ventral arms connected with each other at upper ends; gonocoxite smooth, gently sloped in lateral view, inner and outer dorsal margins nearly parallel; gonostylus truncate apically in lateral view, located at top of gonocoxite, with sparse short hairs; ventral retrorse lobe long, reaching gonobase, with long and dense stetae apically (remaining parts with sparse short hairs) and distinct lineolation; penis valve higher than gonocoxite, without cleft on top.

Distribution

Russian Far East (Siberia, Khabarovsk, and Primorsky), China (Heilongjiang Prov., Shanghai), the Korean Peninsula (north, new record for south).

Flight records

Female: April to September.

Male: July to September.

Flower records

In South Korea, it was collected on the flowers of Potentilla hebiichigo Yonek. & H. Ohashi (Rosaceae) and Brassica sp. ( Brassicaceae ).

Comments

Male specimens from Primorsky and South Korea are studied in the present paper, including characters of the labrum and genitalia. Through this examination, we have concluded that the males of both this species and L. pseudannulipes cannot be clearly separated. A female specimen of this species examined in this study shows weak lineolation on T1 basally (female T1 basally usually with strong lineolation of L. pseudannulipes (see the description of Murao et al. 2009a). Lasioglossum viridellum and L. pseudannulipes could possibly represent the same species. It is difficult to resolve this, because we could not examine enough material of L. viridellum in this study. This problem needs to be addressed by including DNA analysis in a future study.

Figures

Fig. 1. A–E. Lasioglossum (Dialictus) viridellum (Cockerell, 1931). A–B. Head in frontal view. C–D. Labrum. E. Mesepisternum. A, C. ♀. B, D–E. ♂.

Fig. 2. — A–E. Lasioglossum (Dialictus) viridellum (Cockerell, 1931), ♂. — F. L. (D.) aeratum (Kirby, 1802), ♂. — G. L. (D.) aligrum (Blüthgen, 1923), ♂. — H. L. (D.) annulipes (Morawitz, 1876), ♂. — I. L. (D.) leucopus (Kirby, 1802), ♂. A. Genitalia in ventral view. B. Genitalia in dorsal view. C. Genitalia in lateral view. D, F–I. Ventral retrorse lobe of genitalia. E. S7–S8. Scale bars: A–C, E = 0.2 mm, D, F–I = 0.1 mm.