Numbers
>530 spp. in 16 subgenera in our area, 635 spp. in 17 subgenera total
(1)
One of the most speciose bee genera. There are 17 subgenera
(2), 629 described spp. and 125 subspecies, some of which deserve to be elevated to species; numerous species remain undescribed.
(3)
Subgenera not yet in the guide:
Allomacrotera: 2 spp., both in our area
(1)
Alloperdita: 7 spp., all in our area
(1)
Epimacrotera: 15 spp. in our area, 24 spp. total
(1)
Glossoperdita: 3 spp., all in our area
(1)
Hesperoperdita: 2 spp., both in our area
(1)
Heteroperdita: 14 spp., all in our area
(1)
Hexaperdita: 23 spp. in our area, 29 spp. total
(1)
Pentaperdita: 12 spp. in our area, 16 spp. total
(1)
Procockerellia: 4 spp., all in our area
(1)
Pseudomacrotera: monotypic subgenus
(1)
Xeromacrotera: monotypic subgenus
(1)
Xerophasma: 5 spp., all in our area
(1)
Identification
Scopal hairs in females are often quite sparse, so sparse that they would be considered indicative of a male in other species. Females appear to always have a relatively long
scape, similar to Lasioglossum and the males with a quite short scape.
Males have yellow maculations of T5.
Range
Canada to Costa Rica + misc. records in S. America (
map)
(1); diversity is concentrated in deserts (e.g., the Mojave Desert is home to at least 193 taxa, 19 of them undescribed)
(3)Remarks
Females have short scopal hairs because they use moisture to stick the large pollen load to the hind tibia; males have yellow maculations of T5. Some species are active at dawn or dusk. Some members of this genus are the smallest bees in the world.
