BEES ANDRENIDES 



27 



Fig. 14. — D. hirtipes 9- Britain. 



Dasypoda hirtipes appears to be the n:iost higlily endowed of 

 the European Andrenides. The 

 Insects of the genus Dasypoda 

 are very like Andrcna, but 

 have only two in place of three 

 submarginal cells (just beneath 

 the stigma) on the front wing. 

 The female of D. hirtipes has a 

 very dense and elongate pubes- 

 cence on the posterior legs, and 

 carries loads of pollen,each about 

 half its own weight, to its nest. 

 The habits of this insect have been described by Hermann 

 ]\Iitller.-' It forms burrows in the ground after the fashion of 

 Andrena ; this task is accomplished by excavating with the 

 mandibles ; when it has detached a certain quantity of the earth 

 it brings this to the surface by moving backwards, and then dis- 

 tributes the loose soil over a considerable area. It accomplishes 

 this in a most beautiful manner by means of the combined action 

 of all the legs, each pair of these limbs performing its share of 

 the function in a different manner ; the front legs acting with 

 great rapidity — making four movements in a second — push the 

 sand backwards under the body, the bee moving itself at the 

 same time in this direction by means of the middle pair of legs ; 

 simultaneously, but with a much slower movement, the hind legs 

 are stretched and moved outwards, in oar-like fashion, from the 

 body, and thus sweep away the earth and distribute it towards 

 each side. This being done the bee returns quickly into the hole, 

 excavates some more earth, brings it up and distributes it. Each 

 operation of excavation takes a minute or two, the distribution 

 on the surface only about fifteen seconds. The burrow extends 

 to the length of one or two feet, so that a considerable amount of 

 earth has to be brouglit up ; and when the Insect has covered one 

 part of the circumference of the mouth of the hole with loose 

 earth, it makes another patch, or walk, by the side of the first. 

 The main burrow being completed, the Insect then commences 

 the formation of brood-chambers in connection with it. Three to 

 six such chambers are formed in connection with a burrow ; the 

 lower one is first made and is provisioned by the bee : for this 

 1 Ferh. Vcr. Rhcinland, xli. 1884, p. 1. 



