368 



NATURAL HISTORY. 



Closing our account of the Scopulipede Bees with this brilliant foreigner, we must now proceed 

 to notice a few types of another group, to which the name of Dasygastres has been given, in allusion to 

 their having the lower sin-face of the abdomen densely clothed with hairs, upon which they collect and 

 convey home the pollen for the supply of their young. These Bees, represented in Britain chiefly by 

 the genera Osmia and Megachile, present a most interesting variety of habits, and, in fact, examples 

 of all the peculiarities already mentioned, modified in various ways, may be observed among them. 

 Of the first of these genera, Mr. Frederick Smith, in his " Catalogue of British Bees," says : " If I 

 were asked which genus of Bees would afford the most abundant materials for an essay on the diversity 

 of instinct, I should without hesitation point out the genus Osmia." A species described by Reaumur 



under the name of the 

 MASON BEE (Chalico- 

 doma muraria), nearly 

 allied to Osmia, builds 

 its nest, composed of fine 

 sand-grains very firmly 

 united by a salivary 

 secretion, upon the sur- 

 face of walls, selecting, 

 in the first place, some 

 small cavity or hollow 

 which may help to give 

 a firm foundation. Here 

 the insect builds a cell 

 somewhat resembling a 

 small finger-stall, with 

 the opening upwards, 

 smooth on the inside, 

 rough outwardly. When 

 nearly completed this 

 cell is furnished with a 

 supply of food, and an 

 egg is laid in it ; then 



the top is closed, and the industrious mother sets to work to build another cell, and this process is 

 repeated until circumstances induce the female to seek another place. The cells are placed without 

 any particular order, and Dr. Taschenberg says he has never seen more than ten together. This 

 Mason Bee has not hitherto been found in Britain. 



The most abundant British Osmia is the Horned Bee (Osmia bicornis), of which the female is 

 remarkable for having two little horns projecting from the front of her head. This species usually 

 burrows in sandy banks and cliffs, but when living in clayey districts chooses decaying trees, 

 especially willows, for its nests. Another species (Osmia leucomelana) selects for its breeding-places 

 the dead branches of the common bramble, the pith of which it scoops out to a depth of several 

 inches, and then deposits its eggs, with a supply of food, in a series of cells separated by partitions 

 formed of masticated vegetable matter. This Bee shows great ingenuity, for it does not remove the 

 whole of the pith, but leaves portions projecting in the form of rings, which help to make the 

 partitions between the cells. Osmia kirta and some other species burrow into wood; whilst two 

 British species (0. auruknta and bicolor) select ready-made nests in the shells of the common snails 

 (Helix hortensis and H. nemoralis), within the whorls of which they build their cells of gnawed 

 vegetable materials. 



The nearly-allied Bees of the genus Megachile are commonly known as Leaf-cutters, from the 

 habit they have of cutting portions of the leaves of trees and plants for the purpose of lining their 

 nests. The pieces of leaf are cut by the mandibles with the utmost neatness, and when detached are 

 carefully rolled up, tucked between the legs, and flown away with to the nest. The rose, laburnum, 

 and garden acacia seem to be the favourite trees with these insects, which form their nests in 



OSMIA LEUCOMELANA AND ITS NEST. 



