Lasioglossum (Dialictus) submandibulare Niu 2020, sp. nov.
Creators: name: Niu, Zeqing
name: Zhang, Dan
name: Zhu, Chaodong
Publisher: name: Zenodo
Year: 2020
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Hymenoptera
Halictidae
Lasioglossum
Lasioglossum submandibulare

description: Lasioglossum (Dialictus) submandibulare Niu, sp. nov. (Figs 4–5)
Type material. Holotype, female, China, Sichuan, Mao Xian (31º43′N, 103º55′E), 25.V.2011, leg. Zeqing Niu.
Etymology. The specific name means the new species is very similar to Lasioglossum mandibulare (Morawitz, 1866).
Diagnosis. According to the current subgeneric classification of the genus Lasioglossum (Gibbs, 2010), the new species belongs to the subgenus Dialictus. The extraordinary and amazing characters of the new species is its elongated mandible (Fig. 4C) and strongly raised pronotum (Fig. 4G). The new species is very similar to L. mandibulare (Morawitz, 1866) by its elongated mandible. Comparing with the type species of L. mandibulare (Morawitz, 1866) (Astafurova & Proshchalykin, 2018), the species has following characters: head and mesosoma with blue-green metallic reflections; antennal flagellum blackish-brown (Fig. 4A); mandible dark brown (Fig. 4C); all tibiae and tarsi brown (Fig. 5A); punctures on clypeus and supraclypeal area sparser; the dorsolateral angle of pronotum triangle, right-angle apically (Fig. 4D); lateral slope of propodeum smooth, without fine striate (Fig. 4E). Meanwhile, L. mandibulare (Morawitz, 1866) is characterized by: head and mesosoma black, without metallic reflections; antennal flagellum yellowish-brown; mandible yellow; all tarsi yellowishbrown; lateral slope of propodeum with fine striae.
The new species is also similar to L. pronotale Ebmer, 2002 by the strongly raised pronotum, but has the head as broad as long, nearly quadrate in frontal view, while the head of L. pronotale is longer than broad, longitudinal rectangular in frontal view.
Description. Female. BL 7.0 mm (Fig. 5A); head quadrate in frontal view, nearly as broad as long, HW: HL = 48: 47 (Fig. 5B); vertex long, ocelloccipital distance long, about 4 times as long as the lateral ocellus diameter (Fig. 4A); gena obviously broader than eye, GW: EW = 19: 9 (Fig. 4B). Clypeus rectangle, nearly 3 times as broad as long, apical margin truncate (Fig. 4C); mandible elongate, with single preapical tooth (Fig. 4C); forewing with three submarginal cells, 1st equal in length to 2nd and 3rd combined, distal veins (1rs-m, 2rs-m, 2m-cu and distal abscissae of M) weak, marginal cell pointed on anterior margin of wing (Fig. 5B); dorsolateral angle of pronotum triangle, right-angle shaped apically (Fig. 4D), pronotum strongly convex toward to the dorsum (Fig. 4G); propodeal dorsum as long as scutellum, nearly flat, with very fine striae not reaching posterior margin of propodeal dorsum (Fig. 4E); lateral slope of propodeum smooth, without fine striae (Fig. 4E), posterior vertical surface of propodeum carinate along lateral margin, but the carina ill-developed, only up to 2/3 of the lateral margin, lateral carina and transverse carina absent (Fig. 4E); hind basitibial plate present, enclosed by carina; inner hind tibial spur pectinate with two large teeth (Fig. 4H). Clypeus nearly polished, only with a few scattered punctures (Fig. 4C); supraclypeal area very sparsely punctate, i=3–5d (Fig. 4C); paraocular area and frons very densely and finely punctate, i=0.2–1.0d (Fig. 4C); vertex very sparsely punctate, i=5–6d (Fig. 4A); scutellum sparsely punctate, i=1–3d (Fig. 4D); T 1 polished, without punctures (Fig. 4F). Head, mesosoma with blue-green metallic reflections, metasomal terga dull reddish-brown, without metallic reflections (Figs 4F, 5A); mandible dull reddish-brown (Fig. 4C); antenna blackishbrown except flagellum with ventral surface lighter, brown (Fig. 4A); forewing subhyaline with brownish-yellow veins and stigma except R vein brown (Fig. 5B); legs dark brown (Figs 4H, 5A). Clypeus, lower part of paraocular area, vertex, and mesosoma covered sparse dirty-yellowish pubescence. T 2– T 3 with basal whitish tomentum (Fig. 4F). Hind femur and tibia with yellowish plumose hairs forming the scopa (Fig. 4H).
Male. Unknown.
Distribution. China (Sichuan).
Floral association. No information.
Funding This work was financially supported mainly by the National Natural Science Foundation of China (31772487) to Zeqing Niu, the grant (Y229YX5105) from Key Laboratory of Zoological Systematics and Evolution, Chinese Academy of Sciences. Chaodong Zhu acknowledges the supports of the National Science Fund for Distinguished Young Scholars (31625024) and Singapore-China Joint Research Grant (41761144068).
Acknowledgements The authors would like to express their sincere thanks to Dr. Alain Pauly for his assistance in identification of Lasioglossum longirostre, also to Dr. Jason Gibbs, and two anonymous reviewers for their comments and suggestions to streamline and improve the earlier drafts of the manuscript.
description: Published as part of Niu, Zeqing, Zhang, Dan & Zhu, Chaodong, 2020, Extraordinary bees of the genus Lasioglossum Curtis, 1833 (Hymenoptera: Apoidea: Halictidae) from China, pp. 50-58 in Zoological Systematics 45 (1) on pages 54-56, DOI: 10.11865/zs.202005, http://zenodo.org/record/4617914