Insects. 737 



Descriptions of the British Mason-bees fyc. (genus Osmia of Panzer), 

 being a section of the Dasygastres, or hairy -bellied Bees of La- 

 treille: with details of their Economy. By Frederick Smith, 

 Esq., Curator to the Entomological Society. 



Perhaps the economy of no genus of bees has afforded more ample 

 details than the present. We find in Reaumur a minute and inte- 

 resting account of one of the species, which constructs its nest of ag- 

 glutinated sand, fixing it on the sides of walls &c, or availing itself 

 of some cavity or suitable projection for that purpose. This species 

 constructs six or eight cells, placed in irregular proximity ; and the 

 female, having deposited an egg, with a suitable supply of pollen and 

 honey in each, makes a common covering to the whole, filling up 

 the spaces between the cells. This is done with the same material as 

 that of which the cells are composed ; and having completed her task, 

 its appearance is that of a dab of mud, which accident might have 

 placed there. A curious account is also recorded by Spinola, of a 

 species which constructs its cells in the abandoned galls of the oak, 

 and to which he has given the name of Osmia gallarum. Several 

 species select the deserted shells of snails, in the spiral tubes of which 

 they construct their nests. I believe Huber's is the earliest account 

 of this peculiar habit ; it is recorded in the second volume of the 

 c Memoires de la Societe de Physique de Geneve.' The species ob- 

 served was the Apis aurulenta of Panzer, which is synonymous with 

 the Apis tunensis of Fabricius. A species having similar habits has 

 been since described by M. Robineau des Voidy, and named Osmia 

 helicicola, which, as well as O. bicolor, was reared by that author from 

 the deserted shells of Helix nemoralis and H. pomatia. He states 

 that the latter insect lays two eggs in each shell, in separate cells ; 

 and above these she constructs three or four cells of sand, separated 

 by a membranous partition ; he also states that the female egg is al- 

 ways uppermost. This statement I have no doubt is the result of li- 

 mited experience in breeding the insect, it being directly at variance, 

 not only with my own experience, but also with the repeated obser- 

 vations of friends of mine, who have bred this species in numbers ; 

 for not only did the males appear first, in the instances under their 

 notice, but in a state of nature they may be observed some days be- 

 fore any of the females are to be found. The males of the mo it abun- 

 dant species, Osmia bicornis, appear at least a fortnight before the 

 females. It is very probable that in the cases recorded by Des Voidy, 

 some parasite had escaped from the empty cells which he observed, 

 ii 2g 



