Halictus plumbeus Halictus plumbeus Halictus (Chloralictus) plumbeus Dialictus plumbeus Lasioglossum plumbeum Habralictus and Lasioglossum of Saint Lucia and Saint Vincent and the Grenadines, Lesser Antilles (Hymenoptera, Apoidea, Halictidae) Gibbs, Jason Bass, Amber Morgan, Katherine ZooKeys 2022 2022-03-18 1089 125 167 6P2KK (Ashmead 1900) Ashmead 1900 Insecta Halictidae Lasioglossum CoL Animalia Lasioglossum (Dialictus) plumbeum Hymenoptera 0 125 Arthropoda species plumbeum Dialictus   Figs 14 , 15 , 16   Halictus plumbeus Ashmead (1900: 218, 220). Saint Vincent. Syntype males and females (NHMUK, USNM; Fig. 14). Examined.  Halictus plumbeus: Ashmead (1900: 304) checklist; Friese (1909: 37) catalogue; Cockerell (1915: 9) taxonomic note; Cockerell (1938: 280, 281) taxonomic notes.  Halictus (Chloralictus) plumbeus: Sandhouse (1924: 4) identification key; Cockerell (1937: 113) taxonomic notes.  Dialictus plumbeus: Moure and Hurd (1987: 124) catalogue; Moure (2007: 853) catalogue.  Lasioglossum plumbeum: Gibbs (2016: 6, 15) taxonomic notes.  Material examined.  SVG •  Saint Vincent• St. Vincent, leg. H.H. Smith(  Halictus plumbeus syntypes 1 ♀NHMUK, 1 ♀USNM) • St. Vincent( Windwardside), leg. H.H. Smith( 2 ♀USNM) •  Charlotte Parish• Belair Mespo Peruvian Vale Rd., 13.173417 -61.151111,  71 m, 13.V.2016, leg. Miklasevskajaand Ferrari( 1 ♂WRME) • Fancy,  1 kmS of Windwardhwy. 13.380122 -61.170588,  55 m, 18.V.2016, leg. Miklasevskajaand Ferrari( 1 ♂WRME) • Greiggs, CharlotteMtn., 13.222417 -61.173361,  478 m, 14.V.2016, leg. Miklasevskajaand Ferrari( 1 ♂WRME) •  St. Andrew Parish• Vermont Trail Rd., 13.201639 -61.241333,  114 m, 15.V.2016, leg. Miklasevskajaand Ferrari( 1 ♀WRME) •  St.  David Parish• Cumberland Way, 19.IX.1991, leg. R.E. Woodruff, near beach ( 1 ♀ 1 ♂FSCA) • Wallilabou, 14.X.1991, leg. R.E. Woodruff, day catch ( 10 ♀ 2 ♂)•   St. George Parish• Cane Hall, 22.IX.1991, leg. R.E. Woodruff, sweeping ( 4 ♀ 9 ♂FSCA) • Cane Hall,  Rick'sApts., 17.IX.1991, leg. R.E. Woodruff, vacant lot ( 1 ♀FSCA) • Rivulet Agr. Sta. 10-15.X.1991, leg. R.E. Woodruff, Malaisetrap ( 3 ♀FSCA); 27-30.IX.1991, leg. R.E. Woodruff, Malaisetrap ( 1 ♀ 1 ♂FSCA) • Majorca Mts., Riley Rd., 13.180694 -61.193556,  366 m, 13.V.2016, leg. Miklasevskajaand Ferrari( 1 ♀WRME) •  St. Patrick Parish• Cumberland Valley, 17, VI.1977, leg. E.E. Grissell( 11 ♀ 21 ♂FSCA) • Hermitage Forestry Cottage, 11-13.X.1991, leg. R.E. Woodruff, day catch ( 2 ♀ 1 ♂FSCA) • Rutland Vale, 1 kmN on Leeward Hwy., 13.218727 -61.270954,  60 m, 19.V.2016, leg. Miklasevskajaand Ferrari( 1 ♀WRME)•   Grenadines• Bequia, Industry, 24.IX.1991, leg. R.E. Woodruff( 1 ♂FSCA).   Figure 14. Lasioglossum (Dialictus) plumbeum(Ashmead), syntypefemale of  Halictus plumbeusAshmead Adorsal habitus Bhead, frontal view Clateral habitus. Images courtesy of the National Museum of Natural History, Smithsonian Institution. https://collections.nmnh.si.edu/search/ento/  Notes.   Lasioglossum sanctivincentiis quite similar to  L. plumbeum. The most striking difference is the darker blue colour of the head and mesosoma of  L. plumbeum.  Lasioglossum sanctivincentihas a shorter head (face length/head width ratio = 0.82 SD 0.02) than  L. plumbeum(0.86 SD 0.01). Mesoscutal puncture density is subtly different between the two species. In  L. sanctivincentipunctures laterad of the parapsidal line are dense, but distinctly separated. These are nearly reticulate in  L. plumbeum, without clear interspaces. Immediately mesad of the parapsidal line,  L. sanctivincentihas distinctly separated punctures (IS ≤ 1 PD), but these are denser in  L. plumbeum(IS ≤ 0.5 PD).  Ashmead's(1900)original measurements suggest that  L. santivincentiis larger (4-5.5 mm) than  L. plumbeum(3.5-4.5 mm). In  Sandhouse's(1924)key, they separate at couplet 43 based on size and Cockerell (1938)also refers to the smaller size of  L. plumbeum. However, this may be an artefact of H.H. Smith'soriginal sample as more recently collected specimens of  L. plumbeuminclude a large size range (> 5 mm) overlapping with that of  L. sanctivincenti. The size variation in  L. plumbeummay be an indication of weakly defined social castes in  L. plumbeum, which is a common feature of eusocial halictines ( Michener 1990).   Figure 15. Lasioglossum (Dialictus) plumbeum(Ashmead), female Adorsal habitus Bhead, frontal view Clateral habitus.   Figure 16. Lasioglossum (Dialictus) plumbeum(Ashmead), male Adorsal habitus Bhead, frontal view Clateral habitus. 2016-05-13 2016-05-18 2016-05-13 H. H. Smith, Miklasevskaja, Ferrari Saint Vincent Windward 71 13.222417 Fancy 1 -61.173363 Belair Mespo Peruvian Vale Rd. 6 4 2 Charlotte Parish syntypes 2016-05-15 Miklasevskaja, Ferrari Saint Vincent and the Grenadines 114 13.201639 St 1 -61.241333 Vermont Trail Rd. 2 1 1 St. Andrew Parish syntype 1991-09-19 1991-10-14 1991-09-19 Parish, Cumberland Way, R. E. Woodruff Saint Vincent and the Grenadines Wallilabou 14 11 3 David syntype 1991-09-17 2016-05-13 1991-09-17 Cane Hall, R. E. Woodruff, Malaise Saint Vincent and the Grenadines Cane Hall 366 13.180694 Rivulet Agr. Sta. 1 -61.193558 Rick's Apts. 19 9 10 St. George Parish syntype 1977-06 2016-05-19 1977-06 Miklasevskaja, Ferrari, E. E. Grissell, R. E. Woodruff Saint Vincent and the Grenadines Parish 60 13.218727 Hermitage Forestry Cottage 1 -61.270954 Cumberland Valley 37 15 22 St. Patrick syntype 1991-09-24 R. E. Woodruff Grenadines Industry Bequia 1 1 Saint Patrick syntype