1918.] ' 129 



Those who wish to know some of the histological details of Stylops 



would do well to study the paper by Geoffrey Smith and A. H. Hamm, 



that I have frequently referred to. The first-named able zooloj^ist is one 



of those whose loss at the front we have to dej^lore, he having been 



killed by shell-fire in 1916. 



Park Hill House, Paignton. 

 A2vdni]u 1918. 



THE ASSEMBLING AND PAIKING OF STYLOPS. 

 BY K. C. L. PERKINS, M.A., D.Sc., F.Z.S. 



On April 21st I picked up two or three stylo^ized An di^e a a trtm- 

 merana, one of which contained an unhatched 6 puparium, as well as a 

 mature $ . Early next morning, on placing the bee in bright sunshine, 

 the 6 Stylojjs aterrima emerged and soon afterwards paired with the 

 female in the same host. I was able to kill this pair while still attached 

 and make a camera lucida sketch, showing the aedeagus to be inserted 

 into the opening of the brood chamber. When the bee and Stt/Iojys were 

 both dry, the (S of the latter became detached, owing to the slight jerk 

 caused in removing the insects to another box. 



A da}' or two later, an assembly of d Stylops was noticed settled 

 on and hovering round a gorse-bush in the same spot, where the A. trim- 

 nierana had been taken. Several were secured at a single stroke, though 

 some were able to escape through the rather coarse mesh of the net. 

 Supposing at the time that these males also belonged to S. aterrima, 

 one was placed in a glass-topped box with A. trimmerana containing $ 

 Stylops. As no pairing took place, this 6 was removed to another box 

 containing A. wilkella stylopized, this bee having been found at the 

 same time in this condition. Pairing was seen to take place between 

 the 6 and $ Stylops, but they became separated before the means to 

 kill them in situ could be obtained. 



On April 27th three instances of assembling of S Stylops wilkellae 

 were observed in the fiield. One of these assemblies was very remark- 

 able, the individuals covering several inches of a stout, bare thorn -branch, 

 so that it appeared quite white from the wings of the small creatures. 

 Owing to the very thorny nature of the place chosen for assembling, 

 only seven males were secured at the stroke, but not less than fifty must 

 have been present in the cluster, man}'' of which escaped tln-ough the 

 opening and torn side of the net. 



One lot of Stylops was attracted by the aid of a female in the middle 

 of the same field, seven being secured, while others were carried oft" by 



