252 ENTOMOLOGICAL NEWS. [October, 



THE HABITS OF CALIFORNIAN BEES AND WASPS. 



Anthidium emarginatum, its Life-history and Parasites. 

 By ANSTRUTHER DAVIDSON, M. D. , Los Angeles, Cal. 



It is doubtful if they ever dig the hole wherein they nest. I 

 find them in so many different places that I incline to believe they 

 occupy whatsoever hole they find convenient. I have found 

 them most frequently in short tunnels in the bare adobe banks, 

 or in the soft sandstone rocks that form the walls of excavations 

 and cuttings. These tunnels were originally the nesting sites of 

 a species of Anthophora. While this may be considered the 

 normal nesting place of this species of Anthidium, they are dis- 

 posed to occupy any medium-sized hole, either in the ground or 

 in a hollow stem ; one built in the key-hole of a door. The hole 

 or tunnel chosen is lined with the wool gathered from the foliage 

 of Gnaphalium chilense, and G. microcephalum, our western 

 species of everlasting. In this the pollen mass and egg destined 

 to form each cell are deposited, the interval between each mass 

 being composed of the same woolly material firmly compacted. 

 The cells in each hole seem to be regulated solely by its depth 

 and vary accordingly from one to seven. Usually the holes are 

 not more than a few inches deep, but no matter what the depth 

 she almost invariably fills the cavity to the top with this floccu- 

 lent vegetable down, firmly compacted together. The object of 

 this is doubtless to prevent the rain soaking into the cavity and 

 endangering the vitality of the larvae, for which purpose it is 

 most admirably adapted being impervious to, and non-absorbent 

 of water. 



The eggs are deposited in the usual manner and the larvae 

 about the end of August spin their cocoons. These when 

 stripped of the woolly covering and the larval excrement adher- 

 ing to it, present a smooth chestnut-colored surface. They are 

 oblong in shape with blunt ends, and average 6 to 8 lines in 

 length and 3 to 4 in width. On the one end is a small mammil- 

 lary projection showing on the outside a hollow tip. The 

 cocoon on section appears to be slightly thinner towards the 

 mammillated end, and is smooth and glossy silvery internally 

 except opposite the tubercule, where the individual threads are 

 more distinct. The papilla on section shows the external part 

 hollow and coriaceous in texture, the internal lining is here less 



