Lasioglossum (Hemihalictus) sexstrigatus
Creators: name: Murao, Ryuki
Publisher: name: Zenodo
Year: 2021
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Hymenoptera
Halictidae
Lasioglossum
Lasioglossum sexstrigatus

description: Key to species of the Lasioglossum (Hemihalictus) sexstrigatus group in Japan
Females
1. Metasoma generally reddish over entire surface (Fig. 12A) ............................................................... ....................................... Lasioglossum (Hemihalictus) sphecodicolor Sakagami & Tadauchi, 1995
– Metasoma generally black over entire surface .................................................................................. 2
2. Disc of T1 with lineolation (e.g., Fig. 15A–B).................................................................................. 3
– Disc of T1 without lineolation (e.g., Fig. 15C)................................................................................ 12
3. Lineolation of T1 nearly over entire surface (Fig. 15A, D–F) .......................................................... 4
– Lineolation of T1 over part of surface (Figs 15B, 16A–C, E)........................................................... 7
4. Ridges of metapostnotum short, reaching anterior half (Fig. 9F) (distribution: northern to central Ryukyus)......................................................................... L. (H.) smilodon Ebmer & Sakagami, 1994
– Ridges of metapostnotum long, reaching posterior margin (Figs 4F, 7F, 8F) ................................... 5
5. IS of mesoscutum nearly smooth on posterior margin; T1 with silky dull luster................................ .......................................................................................... L. (H.) ohei Hirashima & Sakagami, 1966
– IS of mesoscutum with distinct tessellation over entire surface; T1 with enamel-like luster ........... 6
6. Head longer than wide or slightly longer than wide (HL/HW ratio= 1.02–1.07, n =5) (restricted to coastal sand dunes) ......................................................... L. (H.) frigidum Sakagami & Ebmer, 1996
– Head wider than long or nearly as long as wide (HL/ HW raito= 0.94–1.0, n =5) (distribution: Izushotô Islands) .............................................................................. L. (H.) simplicior (Cockerell, 1931)
7. Ridges of metapostnotum short, reaching anterior half (Fig. 5F) (distribution: Ryukyus) ............... 8
– Ridges of metapostnotum long, reaching posterior margin or anterior ⅔ (Figs 10F, 11E, 13E)..... 10
8. Disc of T1 with sparse short hairs (Murao 2012: fig. 7)....... L. (H.) tadauchii Murao, 2012 (in part)
– Disc of T1 withtout distinct hairs (Fig. 15B)..................................................................................... 9
9. Disc of T1 with very weak lineolation on only basally ....................................................................... ...................................................................... L. (H.) amamiense Ebmer & Sakagami, 1994 (in part)
– Disc of T1 with very weak lineolation interrupted on medial area (Fig. 15B).................................... ......................................................................................................... L. (H.) ikudomei Murao sp. nov.
10. IS of mesoscutum medially to posteriorly smooth (Fig. 11D)............................................................. ................................................................................................. L. (H.) speculinum (Cockerell, 1925)
– IS of mesoscutum medially to posteriorly tessellate (Figs 10E, 13D) .............................................11
11. Metapostnotum dimly shiny, with distinct tessellation among ridges (Fig. 10F)................................ ..................................................................................................................... L. (H.) spectrum sp. nov.
– Metapostnotum shinier, without distinct tessellation among ridges (Fig. 13E) .................................. .............................................................................................................. L. (H.) subsimplicior sp. nov.
12. Disc of T1 with distinct hairs and PP (Fig. 15C)............................................................................. 13
– Disc of T1 without hairs and PP (Fig. 16F)..................................................................................... 14
13. IS of mesoscutum medially to posteriorly nearly smooth (Fig. 6D) ................................................... ................................................................................................ L. (H.) kiautschouense (Strand, 1910)
– IS of mesoscutum medially to posteriorly distinctly tessellate (Murao 2012: fig. 3) (distribution: central Ryukyus) ................................................................... L. (H.) tadauchii Murao, 2012 (in part)
14. Distal process of labrum with horn-like lateral projection (Fig. 14D) ................................................ .................................................................................................... L. (H.) taeniolellum (Vachal, 1903)
– Distal process of labrum without lateral projection (e.g., Fig. 4D) ................................................. 15
15. Ridges of metapostnotum short, reaching anterior half (Murao et al. 2010: fig. 1N) (distribution: central Ryukyus) ........................................... L. (H.) amamiense Ebmer & Sakagami, 1994 (in part)
– Ridges of metapostnotum long, reaching posterior margin................................................. L. (H.) sp.
Males
1. Metasoma generally reddish over entire surface as in female (Fig. 12A)........................................... ....................................... Lasioglossum (Hemihalictus) sphecodicolor Sakagami & Tadauchi, 1995
– Metasoma generally black over entire surface .................................................................................. 2
2. Clypeus nearly black, without distinct yellow spot on lower half (Figs 5C, 9C).............................. 3
– Clypeus with a distinct yellow spot on lower half (Figs 4C, 7C, 8C, 10C, 14C).............................. 4
3. F2 long, over 1.5× F1.................................................................................. L. (H.) ikudomei sp. nov.
– F2 short, under 1.5× F1....................................................... L. (H.) amamiense Ebmer & Sakagami, 1994 and L. (H.) smilodon Ebmer & Sakagami, 1994 (species with allopatric distributions)
4. F2 long, over 1.5× F1........................................................................................................................ 5
– F2 short, approximately or under 1.5× F1......................................................................................... 6
5. Head wider than long, HL/ HW ratio 0.90–0.96......................... L. (H.) taeniolellum (Vachal, 1903)
– Head longer than wide, HL/ HW ratio 1.04–1.07 (restricted to coastal sand dunes) .......................... ........................................................................................ L. (H.) frigidum Sakagami & Ebmer, 1996
6. F2 nearly as long as F1; labrum without basal elevation..................................................................... .......................................................................................... L. (H.) ohei Hirashima & Sakagami, 1966
– F2 1.4–1.5 × F1; labrum with a distinct basal elevation (Fig. 2B) ...................................................... ............................... L. (H.) simplicior (Cockerell, 1931), L. (H.) spectrum sp. nov., and L. (H.) sp.
description: Published as part of Murao, Ryuki, 2021, Redefinition of the sexstrigatus group of Lasioglossum (Hemihalictus) Cockerell, 1897 (Hymenoptera, Apoidea, Halictidae), with a revision of Japanese species, pp. 1-74 in European Journal of Taxonomy 763 on pages 59-60, DOI: 10.5852/ejt.2021.763.1463, http://zenodo.org/record/5235968