BEES OF GREAT BRITAIN. 1 73 



Genus 8. MEGACHILE. 



Apis, pt., Linn. Faun. Suec. p. 419 (1687). 

 entris, pt., Fabr. Syst. Piez. p. 354 (1804). 

 Anthidium, pt., Fabr. Syst. Piez. p. 364. 

 Anthophora, pt., Fabr. Syst. Piez. p. 372. 

 Megachile, pt., Latr. Hist. Nat. xiv. 51 (1805). 

 Trachusa, pt., Jurine, Hym. (1808). 



Labial palpi four-jointed, the two basal joints elongate, of 

 about equal length, attenuated, the second joint having the 

 apex acute ; the third and fourth joints minute, clavate, placed 

 at the side and near the apex of the second joint ; the palpi about 

 the same length as the labium, which is cylindric and longitu- 

 dinally channeled and pubescent. The maxillary palpi two- 

 jointed, the basal joint very short, stout and subglobose, the se- 

 cond joint slender and eylindric ; the apical lobe of the maxilla? 

 elongate, lanceolate and curved. The superior wings have one 

 marginal and two submarginal cells, the second submarginal re- 

 ceiving the two recurrent nervures. The head is usually as wide 

 as the thorax ; the mandibles are very stout ; the ocelli are placed 

 in a triangle on the vertex ; the females have a dense pollen- 

 brush on the under side of the abdomen. In some species the 

 males have the apical joint of the antennse compressed and di- 

 lated, and some have dilated anterior tarsi. 



The bees included in the genus Megachile are popularly 

 called Leaf-cutters, from the circumstance of their cutting off 

 pieces of the leaves of various trees, for the purpose of forming 

 the cells in which they store up the food for their larvae ; they 

 appear to prefer the Rose and Laburnum. Many very interest- 

 ing accounts of their habits have been written ; some of 

 the species select decaying trees, posts and rails, in which 

 to form their tunnels ; this habit I have observed in M. Wil- 

 lughbiella and ligniseca, which never appear to choose any other 

 material: I have seen M. maritima burrowing in decaying 

 wood, but in Sandown Bay, Isle of Wight, where the species 

 is abundant, it burrows in the cliffs : M. centuncularis at one 

 time chooses an old post or decaying tree, at another the soft 

 mortar of an old wall, and sometimes burrows in the ground ; 

 J have bred this insect from cells obtained from each of the above 



