THE CUCKOO BEES 15 



with, and are never found except with that 

 species. There are, however, cases of cuckoos 

 which visit the nests of more than one host, and 

 cases of hosts which are visited by several kinds 

 of cuckoos. In the short-tongued bees, with the 

 exception of Hcdictus and Sphecodes, the cuckoos 

 are quite unlike their hosts both in form and 

 colour. In the Andrenas (the lawn bee being 

 one of them) the hosts are clothed with reddish, 

 or brown and black, hairs, and are of a more 

 or less stout build (pi. B, 15, 16). The cuckoos 

 are elegant in shape, almost devoid of hairs, and 

 most of them are striped with yellow or brown 

 across the body so that they present a wasp-like 

 appearance (pi. B, 18). Species more unlike one 

 another than host and cuckoo one could hardly 

 imagine ; still this stranger seems to get access 

 to the nest of its host without opposition. In 

 a colony of Andrena one may see the cuckoos 

 (which rejoice in the name of Nomada or 

 wanderers) flying about among the females of 

 the industrious bee, and no alarm or concern 

 appears to be felt by the latter. As we go up in the 

 scale of bees, i.e. towards the more specialized, 

 and arrive at those with longer tongues, the 



