The Resin-bees 



the Snail-shell would know how to enforce her 

 rights as the first occupant. 



For the summer Resin-bee, Atith'idium belli- 

 cosum, the conditions are very different. At 

 the moment when the Osmia is building, she is 

 still in the larval, or at most in the nymphal 

 stage. Her abode, which would not be more 

 absolutely silent if deserted, her shell, with its 

 vast untenanted porch, will not tempt the 

 more forward Resin-bee, who herself wants 

 apartments right at the far end of the spiral, 

 but it might suit the Osmia, who knows how 

 to fill the shell with cells up to the mouth. 

 The last whorl left vacant by the Resin-bee is 

 a magnificent lodging which nothing prevents 

 the mason from occupying. The Osmia 

 seizes upon it, in fact, and does so too often 

 for the welfare of the unfortunate late-comer. 

 The final resin lid takes the place, for the 

 Osmia, of the mud stopper with which she 

 cuts off at the back the portion of the spiral 

 too narrow for her labours. Upon this lid 

 she builds her mass of cells in so many storeys, 

 after which she covers the whole with a thick 

 defensive plug. In short, the work is C(jn- 

 ducted as though the Snail-shell contained 

 nothing. 



317 



