Key to the Halictidae of Dominica

1. Head and mesosoma lacking metallic reflections; female without scopa ………………………2 – Head and mesosoma with metallic reflections; female with scopa ……………………………4

2. Legs entirely orange-testaceous (Figs 15B, 16B); mesepisternum reddish to testaceous; marginal cell with basal fourth or less subtended by submarginal cells; metapostnotum completely covered in reticulate rugae (Figs 15C, 16C) ……………… Microsphecodes dominicanus (Stage, 1972)

– Legs mostly dark brown (Figs 9B, 10B, 11B, 12B); mesepisternum black; marginal cell with basal third or more subtended by submarginal cells; metapostnotum with longitudinal carinulae restricted to basal portion (Figs 9C, 10C, 11C, 12C) ………………………………3

3. Male face mostly bare (Fig. 9A); female metasoma red on T1–T4 (Fig. 10B); both sexes with mesepisternum below scrobe with smooth triangular posterior area (Fig. 13A) …………………… ……………………………………………………………………... Sphecodes diablotinus sp. nov.

– Male face covered in white pubescence (Fig. 11A); female metasoma red on T1–T3 (Fig. 12B); both sexes with mesepisternum below scrobe with narrow smooth posterior margin (Fig. 13B) ………………………………………………………………………… Sphecodes albifacies sp. nov.

4. Metallic red colouration extending over entire body, distinctive on metasomal terga (Fig. 22B); female T5 with median longitudinal specialized area divided; male T7 without preapical carina forming false apex ……………………………… Augochlora ignifera Crawford, 1914

– Metallic colouration limited to head and mesosoma; female T5 with median longitudinal specialized area not divided (may be absent); male T7 with preapical carina forming false apex ……………………………………………………………………………………………………5

5. Head and mesosoma with granular microsculpture, mesoscutal punctation sparse and often obscure; metapostnotum without distinct rugae or carinulae covering most of the surface; female without T1 appressed setose fan …………………………………………………………6

– Head and mesosoma with imbricate microsculpture; mesoscutal punctation dense at least laterally and distinct; metapostnotum with distinct rugae or carinulae covering most of the surface; female with T1 appressed setose fan ……………………………………………………9

6. Two submarginal cells (Fig. 8B); mesoscutal punctation sparse, but distinct; male unknown ………………………………………………………………… Lasioglossum roseauense sp. nov. – Three submarginal cells; mesoscutal punctation obscure …………………………………………7

7. Second and third submarginal cells weak; head longer than wide (length/width ratio = 1.02; Fig. 7A); male unknown (antenna unlikely to be clavate) …………………………………………… ……………………………………………………… Lasioglossum punctifrons (Crawford, 1914)

– Second and third submarginal cells strong; head usually wider than long (length/width ratio = 0.84–0.97); male with clavate antenna, slender T1–T2 (Figs 18B, 21 B–C) ………………...8

8. Clypeal yellow or dark brown distal maculation narrow (1/5 longitudinal distance in male, ¼ longitudinal distance in female) (Figs 17A, 18A); metapostnotum longitudinal length greater than apical width (Figs 17B, 18B); male head distinctly wider than long (length/width ratio = 0.84–0.85) (Fig. 18A) ………………………………………… Habralictus antillarus sp. nov.

– Clypeal yellow or dark brown distal maculation broad (¼ longitudinal distance in male, ½ longitudinal distance in female) (Figs 20A, 21A); metapostnotum longitudinal length subequal to apical width (Figs 20B, 21B); male head narrower (length/width ratio = 0.95–0.96) (Fig. 21A) ………………………………………………………………… Habralictus gonzalezi Gibbs, 2012

9. Hypoepimeral area finely rugulose, without distinct punctures; mesepisternum below scrobe reticulate-rugulose; mesoscutal setae a mix of brown and dull white; male unknown ……………… ……………………………………………………………………… Lasioglossum kalinago sp. nov.

– Hypoepimeral area smooth, with distinct punctures; mesepisternum below scrobe punctate; mesoscutal setae dull white ………………………………………………………………………10

10. Head short (length/width ratio = 0.9; Figs 2A, 3A); smaller in size (body length ~ 4 mm) …… ………………………………………………………………… Lasioglossum dominicense sp. nov.

– Head longer (length/width ratio = 1.0; Figs 5A, 6A); larger in size (body length ~ 5 mm) …… ………………………………………………………………… Lasioglossum kilpatrickae sp. nov .