Insects. 1663 



larger or more gaily coloured species of bees. As far as I have ob- 

 served the habits of this genus, I have found them to be burrowers in 

 the ground, the species differing in the choice of their situations : 

 some prefering sloping banks of light earth, as A. bicolor, nigro-senea, 

 tibialis, &c. ; others, as A. Rosae, fulvescens, albicrus, &c, choosing 

 hard-trodden sandy path-ways. Their burrows are usually from six 

 to ten inches in depth : having stored up a sufficient supply of pollen 

 and honey for one grub, the bee deposits an egg and closes up the 

 cell ; this she repeats until the necessary number of cells are stored ; 

 when, her task being completed, she carefully closes up the mouth of 

 the cell. 



Notwithstanding all the care and assiduity with which these bees 

 protect and provision their nests, they are subject to the parasitic in- 

 trusion of various insects ; thus, the Genus Noniada are almost exclu- 

 sively parasitic upon these bees, some indeed, appear to attach them- 

 selves to particular species ; thus, Nomada ferruginata 1 never found 

 frequenting any other nests than those of A. fulvescens, — Nomada 

 baccata, those of A. argentipes, &c. : to some extent these connexions 

 appear constant, but occasional deviations from the force of circum- 

 stances will no doubt be met with. A wide field for investigation yet 

 remains unexplored as to the true nature of the connexion between 

 the industrious bee and its parasite. I have found the Nomada sex- 

 fasciata in the cells of Eucera longicornis, — and here I may observe 

 another instance of admirable foresight, a beautiful adaptation of eco- 

 nomy to circumstances — Eucera longicornis being a much larger in- 

 sect than its parasite, of course stores up double the quantity of food 

 required by one larva of the Nomada, two eggs are consequently de- 

 posited ; whether this is always the case I do not know, but having 

 in two instances found it so, we may reasonably draw this conclusion. 

 Independently of the attacks of parasitic bees upon the food of the 

 larva, the bodies of the perfect insects are infested by various species 

 of Stylops : in my own collection I have about twenty different spe- 

 cies thus attacked. The orange-coloured larva of Meloe is also found 

 upon various species, as well as a larger black larva, named by Mr. 

 Kirby, Pediculus Melittae ; what this is really the larva of, has not 

 been correctly ascertained. I have also occasionally found a minute 

 species of Acarus infesting them. 



The sexes of many of the species are so very dissimilar, that it is 

 only by close attention to their habits they can ever be correctly 

 united ; many are still unknown, but several have been ascertained 

 since the publication of Mr. Kirby's Monograph; the following spe- 



