12 THE DENIZENS OF AN OLD CHERRY TREE. 



says : — " How A. furcata came to exist as a single female in the 

 stump is curious. One would have thought that more examples 

 would have been in the same burrow ; possibly, however, these 

 died." After all the specimens of C. vagus had appeared, we 

 carefully examined the pieces of cherry wood in which it had 

 burrowed, but no other example of the bee in any stage could be 

 found. The gallery of the burrow from which the bee had 

 emerged had been much enlarged, and contained some wood 

 debris, of much finer particles than that in the other portions of the 

 Crabro burrow, from which we infer that the parent bee had 

 cleaned out, enlarged, and utilised for its nidus, a portion of the 

 Crabro home. 



We now come to the most numerous, but one of the varied, 

 inhabitants of the stump, viz., Crabro chrysostof?ws {¥\g. 4, PI. I.), 

 where a female is drawn natural size with three of the vandyke- 

 brown cocoons in situ in the burrows, with their anal ends resting 

 on and partially, attached to the larder remains, which appear to 

 be chiefly specimens of the genus Platychirus. An untouched 

 larder in a portion of wood, consisting of several borings, with 

 cocoons of this Crabro, contained eight specimens of Platychirus 

 fulviventris. Of this interesting fossore we bred sixty-four males 

 and twelve females during May and June. The males, when 

 handled or touched, exhale a rich odour. The female can emit 

 the scent, but in a much less degree. This agreeable perfume we 

 have noticed when examining certain species of bees {Halicti), 

 but have not met with it in connection with other species of 

 Crabro. C chrysostomus is subject to the attacks of the parasitic 

 hymenopteron Pteromalus apum, mentioned previously in connec- 

 tion with C. leucostomus. 



The last inmate of our stump to notice is Crabro cephalotes 

 (Fig. 6, Plate II.), the finest fossore of our series, and of which ten 

 males and four females made their exit from the cocoons. The 

 cocoon is shaped like C chrysostofuus, and of the same colour, but 

 rather larger. Fig. 4, PI. II., shows a pupa removed from its cocoon. 

 The burrows of this species contain the remains, and sometimes 

 whole specimens of the largest dipterous prey found in the stump. 

 In one nidus we found three whole specimens of Rhirigia rostrata^ 

 and in another burrow were examples of Syrphus ribesii, insects 



