Key to Chinese species of Anthidiellum

1. Flagellum 11-segmented, male........................................................................... 2

-. Flagellum 10-segmented, female......................................................................... 6

2. S5 without comb of black teeth.......................................................................... 3

-. S5 with comb of black teeth (Figs. 8 g, 11g)................................................................. 5

3. Omaular carina with a shallow concavity on upper margin (Figs. 2 f, 3f); scutellum with posterior margin distinctly angled inward to midpoint (Fig. 3 d); paraocular area with yellow maculation extending above antennal socket (Fig. 3 b).......... 4

-. Omaular carina straight, without a shallow concavity on upper margin (Fig. 5 f); scutellum with posterior margin broadly rounded outward except for narrow, shallow notch medially (Fig. 5 d); paraocular area with yellow maculation not extending above antennal socket (Fig. 5 b).................................. Anthidiellum (Anthidiellum) yunnanense (Wu, 1962)

4. Apical margin of T6 with well-developed lateral lobe in addition to medial spike (Fig. 3 g); T2 coarsely punctate (Fig. 3 e)............................................................... Anthidiellum (Anthidiellum) scutellatum Wu, 2004

-. Apical margin of T6 with medial spike but without lateral lobe; T2 finely punctate (Fig. 2 e).......................................................................................... Anthidiellum (Anthidiellum) boreale Wu, 2004

5. Hind tibia with longitudinal carina on outer face; T2 black, without yellow maculation laterally (Fig. 8 e); axilla yellow (Fig. 8 d)....................................................... Anthidiellum (Pycnanthidium) carinatum (Wu, 1962)

-. Hind tibia without longitudinal carina on outer face; T2 with yellow maculation laterally (Fig. 11 e); axilla black (Fig. 11 d).......................................................... Anthidiellum (Pycnanthidium) latipes (Bingham, 1897)

6. Hind tibia and hind basitarsus each with a longitudinal carina on outer face (Fig. 7 f); mandible with three teeth (Fig. 7 c).............................................................. Anthidiellum (Pycnanthidium) carinatum (Wu, 1962)

-. Hind tibia and hind basitarsus both without a longitudinal carina on outer face (Figs. 4 f, 9f); mandible with four teeth, though third tooth sometimes very small (Figs. 1 c, 4c, 6c, 9c)........................................................ 7

7. Hind basitarsus stout (Figs. 9 f, 10f), width as wide as greatest width of hind tibia.................................. 8

-. Hind basitarsus slender (Fig. 6 a), width much less than greatest width of hind tibia................................. 9

8. Posterior margin of scutellum black (Fig. 10 d).................... Anthidiellum (Pycnanthidium) latipes (Bingham, 1897)

-. Posterior margin of scutellum yellow, with two yellow markings (Fig. 9 d).................................................................................................... Anthidiellum (Pycnanthidium) coronum (Wu, 2004)

9. Forewing with veins bicolored, basally dark and distally yellow including stigma (Fig. 6 e); mandible much broader apically than basally (Fig. 6 c); T1-T3 black, without yellow maculation (Fig. 6 e).. Anthidiellum (Clypanthidium) popovii (Wu, 1962)

-. Forewing with veins all dark (Fig. 1 a); mandible scarcely broader apically than basally; at least T2-T3 with yellow maculations laterally (Fig. 1 e, 4e)................................................................................. 10

10. Omaular carina with shallow concavity on upper margin (Fig.1 f); scutellum with posterior margin distinctly angled inward to midpoint (Fig. 1 d); paraocular area with yellow maculation (Fig. 1 b)....... Anthidiellum (Anthidiellum) boreale Wu, 2004

-. Omaular carina straight, without a shallow concavity on upper margin (Fig. 4 f); scutellum with posterior margin broadly rounded outward except for narrow, shallow notch medially (Fig. 4 d); paraocular area black, without yellow maculation (Fig. 4 b)........................................................ Anthidiellum (Anthidiellum) yunnanense (Wu, 1962)