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Zoology of Colorado 



A parasitic bee. Bom- 

 bomelecta johnsoni Ckll. 

 Type. Evelyn Moore del. 



(9) Triepeolus is richly represented by 

 30 species, all parasitic, probably without 

 exception in nests of Anthophoridae. 

 These bees are elegantly marked with light 

 bands and spots, which appear at first to 

 be on the actual surface, as in Anthidium. 

 Closer inspection shows that they are due 

 to a minute felt-like tomentum, which can 

 be readily scraped off. The maxillary palpi 

 have three joints, but in the closely related 

 Epeolus there are only two joints. There 

 are in Colorado several other related genera of parasitic bees, 

 which we will not attempt to describe in this place. A very 

 peculiar one (Neolarra) was originally described as a wasp. 



(10) Nomada is another parasitic genus, the species prettily 

 marked on the actual surface with yellow, whitish or ferruginous 

 red. They look like small wasps, and are often regarded as such. 

 The maxillary palpi are six-jointed, instead of being highly mod- 

 ified as in Triepeolus. We have 74 species in Colorado, but very 

 little is known about their habits. It is probable that nearly all 

 infest the species of Andrena, which may be found nesting in the 

 ground. 



(11) Panurginus consists of small black bees with only two 

 cubital cells, and the marginal cell truncate (as though amputated) 

 at the end. The males have conspicuous light face markings. 

 We have 22 species known at the present time, some of them quite 

 common in the mountains. The related Spinoliella differs 

 principally by the light markings of the abdomen. The genus 

 Perdita, already mentioned above, differs from these by the much 

 shorter marginal cell. Most of the species are gaily marked in 

 wasp-like fashion, but very small. 



(12) Halictus is found all over the world, wherever bees can 

 live. Hundreds of species are known, of which 79 have been 

 reported from Colorado. While many species are black, many 

 show green or bluish colors, especially on the head and thorax. 

 The genus may be recognized as a rule by the pointed marginal 

 cell, three cubital cells, and the basal nervure (which extends 

 downward obliquely from the corner of the first cubital cell) 

 strongly arched or curved. They nest in the ground. The two 



