Megachile (Litomegachile) snowi Mitchell, 1927

Bzdyk, Emily L., 2012, A revision of the Megachile subgenus Litomegachile Mitchell with an illustrated key and description of a new species (Hymenoptera, Megachilidae, Megachilini), ZooKeys 221, pp. 31-61 : 49-50

Megachile (Litomegachile) snowi Mitchell, 1927 stat. n.

Megachile mendica snowi Mitchell, 1927:113 Holotype female, USA: Arizona (MCZ).

Diagnosis.

Megachile snowi is distinguished from Megachile mendica in males by the presence of a complete apical fringe of white hair on T5. Megachile mendica has little or no apical fringe of white hair on T5. Female Megachile snowi have white appressed pubescence on T6, and the few black scopal setae of S6 are only found apically. Megachile mendica has brown pubescence on T6, and S6 has more black setae.

Female. Body length 11-13 mm. Mandible 4-toothed, with surface between teeth 3 and 4 angulate (Figure 4B). T2-4 with shallow transverse basal groove. T1-5 with apical fringes of white hair covering marginal zone; T1-2 with medially interrupted fringes of white hair. T1-2 with white discal pubescence; T3-5 with black discal pubescence. T6 straight in profile and slightly concave laterally in dorsal view; without erect setae, with white appressed pubescence. S1-5 with yellow setae; S6 with yellow setae and few black setae apically (Figure 5H).

Male. Body length 8-10 mm. Mandible 3-toothed.Ocellocular distance less than ocelloccipital distance (Figure 4C). Mesosoma with white pubescence. T1-3 with white discal pubescence; T4-5 with white pubescence basally, black apically. T2 with thin apical fringe of white hair. T5 with complete apical fringe of white hair covering marginal zone. T6 with tomentum (Figure 6E);transverse carina with a distinct medial notch; true apical margin with submedial teeth closer to each other than to lateral teeth, or distances equal (Figure 6A). Genitalia and hidden sterna shown in Figures 7F1-F4.

Distribution of material examined.

USA: Arizona: Cochise County (Aug.-Sep.); California: Mariposa County (May); Colorado: Boulder County (May-Jun.); New Mexico: Catron County (Jul.); Utah: Cache, Garfield, Kane and Salt Lake Counties (May-Aug.); MEXICO: Zacatecas.17 females, 35 males.

Flower records.

Cirsium sp. ( Asteraceae ), Helianthus sp. ( Asteraceae ), Melilotus alba ( Fabaceae ).

Comments.

This species was originally described as a subspecies of Megachile mendica (Mitchell, 1935). It is raised to species level herein, based on reliable morphological characters distinguishing it from Megachile mendica , and an overlapping range with the latter (Figures 12, 16). Mitchell (1935) found a male Megachile cleomis cotype to be misidentified, and previously synonymized it under Megachile mendica snowi .See Megachile texana comments. Megachile snowi is a southwestern North America species (Figure 16).