PSYCHE. 



THE HABITS OF THE ACULEATE HYMENOPTERA.— H 



BY WILLIAM H. ASHMEAD, WASHINGTON, D. C. 



Mr. E. Buynes Reed, in "Notes on 

 Alegachile brevis Say" (Can. ent. v. 3, 

 1S71, p. 210) has figured this species 

 and records the following respecting it. 



While inspecting during tlie past summer, 

 the fruit orchard of a friend residing in this 

 neighborhood, my attention was attracted by 

 the peculiar appearance of the leaves of a 

 young plum tree. At the tirst glance, I 

 thought it might be affected by Aphides, but, 

 on closer examination, I found unmistakable 

 evidence of the work of a leaf-cutting bee, in 

 the circular holes in many of the leaves, and 

 on opening one of the coils of leaves, of 

 which there were four or five, I discovered 

 the curious chambers of the bee, each con- 

 taining a half grown grub comfortably 

 ensconced, with its modicum of food. I 

 took some of the coils home, but only suc- 

 ceeded in rearing two perfect insects. 



The genus Ost?iia, structurally, is 

 closely allied to Megachile, but the 

 species composing it construct nests 

 entirely different. The}' have received 

 the name of "mason-bees," from the 

 way they construct small earthen cells 

 under stones, in burrows excavated in 

 decaying wood, rotten posts and twigs, 

 in deserted snail-shells, in cynipidous 

 galls, or elsewhere. 



Very little seems to be known respect- 

 ing the habits of the North American 

 species, Dr. Packard, in his Guide, 

 being apparently the only author who 

 has written anything about them. From 

 his observations and those published 

 abroad, the species exhibit great diver- 



sity of habits and should be mr;re care- 

 fully studied, as this diversity of habits 

 will no doubt be found correlated with 

 structural differences that will justify 

 sub-generic divisions of this large genus. 



The cells are constructed of sand, 

 earth, or clay, agglutinated and mixed 

 with pebbles or the raspings of wood, 

 held together by a glutinous substance 

 secreted by the female ; internally the 

 cells are always smooth, but externall)- 

 they are rough in conformity with the 

 material used in their construction. 

 These cells vary in number in each nest, 

 usually from 10 to 20 being found 

 together. Each cell contains a deposit 

 of honey-paste for the subsistance of the 

 larva, only a single larva or egg being 

 found in each cell. Curtis found the 

 enormous number of 230 cells of the 

 European Osinia parietina attachetl to 

 the under side of a large flat stone. Mr. 

 L. O. Howard, in his article in the 

 Standard Natural History, calls atten- 

 tion to a remarkable case of retarded 

 development in this species observed by 

 Mr. Frederick Smith. "From a quan- 

 tity of cells collected in Scotland in 

 1S49, about one-third only had given 

 forth the adult bees. Some of the re- 

 mainder issued the following year, while 

 about thirty-five remained in the larva 

 state until May, 1851, when they trans- 

 formed and issued a month later." 



One of our largest species, Osrnia lig- 

 nivora Pack., according to Dr. Packard, 



