1929] 
Biology of Mining Bees 
167 
Strasburg takes two years to accomplish the life cycle of 
one generation. “Some of the species make burrows in cliffs 
and form large colonies which are continued for many years 
in the same locality.” 
Say, in referring to the habits of European A. parietina, 
says that this species digs a hole in a clay bank and that the 
entrance consists of a cylinder extending downward more 
than an inch in length and made of small pellets of earth 
compacted together, rough on the exterior and smooth 
within. 
Hungerford and Williams 1 made note of the nesting 
habits of A. occidentals, which they call the “larger 
tube-building cliff bee.” The method of nest-building 
is very similar to that described for A. abrupta, for they 
say: “Their tunnels are % inch in diameter and extend 
into the bank about eight inches where they end in several 
cells. The cells . . are so made that when dug out they 
come from the gallery as separated urn-shaped nodules of 
uniform size. The entrance of the tunnel is protected by a 
curved tube from % to 2 inches in length. The tubes bend 
downwards and very often the top or outer curve is split 
longitudinally.” In view of the fact that Hornia minutifen- 
nis Riley was found to be parasitic on the members of the 
Wickes colony, it is interesting to learn that these students 
discovered a new species of beetle, Hornia gigantea, para- 
sitic upon A. occidentalis. 
Frison has discovered a colony of A. abrupta near Oak- 
wood, Illinois, and in an interesting paper 2 gives many 
details of the life history of this species. He finds them nest- 
ing in a clay bank, carrying water for mining operations, 
and on the whole conducting themselves in every way like 
the bees at our clay bank. His paper includes a valuable 
review of the American species of Anthophora. 
Walsh found this species making burrows in the mortar 
in brick work, and also in the face of a precipitous clay 
bank. In California, A. stanfordiana shows a similar 
preference for nesting in a steeply inclined surface. They 
build chimneys over the entrances of their burrows. 
1 Ent. News. 23:258 1912. 
2 Trans. Amer. Ent. Soc. 48: 137-156. 1922. 
