94 COLOUR SENSE IN A KEYHOLE WASP. 



indeed of any of the solitary species of wasps and bees, so that 

 this observation of Major Platt's seems to be unique, and is of 

 extreme interest. The late Lord Avebury, when Sir John 

 Lubbock, made most careful experiments on the colour sense 

 of bees and gregarious wasps, and came to the conclusion that 

 bees possessed more than wasps, and had a decided preference 

 for blue. Of wasps (i.e. gregarious wasps, Vespa) he says, 

 " I satisfied myself that wasps are capable of distinguishing 

 colour, though they do not seem so much guided by it as bees 

 are." ["Ants, Bees and Wasps," Lubbock, 1882, p. 316]. 

 Full details of these interesting experiments are given in this 

 work. The fact that blue appeared to be the bees' favourite 

 colour supports the conclusion that the keyhole wasp or wasps 

 there is no evidence to shew whether more than one 

 individual was concerned chose the three light blue reels 

 because of a colour preference, and not from some peculiar 

 smell of the light blue dye, or by some accidental coincidence. 

 It would be worth while making a more extensive experiment 

 by exposing a larger number of reels painted with different 

 colours several of each on the chance of attracting these 

 keyhole wasps, and noting the result. Dr. Haines, of Ower- 

 moigne, to whom I wrote on the subject of the specific identity 

 of this wasp, tells me that he has found 13 out of the 17 British 

 species of Odynerus in Dorset, most of them commonly; 

 and that four of these build in similar positions to the present 

 one (0. parietwn, L., pictus, Curt., parietinus, L., and antilope, 

 Panz., a large species). The identity of the present species 

 cannot therefore be stated with certainty until the perfect 

 insect emerges, which it will probably do in the early summer. 



NOTE. August, 1920. 



Major Platt very kindly gave me one of the reels of light 

 blue cotton containing cells of Odynerus, and from this I bred 

 on July 18th and 19th, 1920, two female wasps, which Dr. 

 Haines pronounces to be Odynerus parietinus, Linn., thus fixing 

 the species which was the subject of this interesting observation. 

 In another reel, which Major Platt presented to the Dorset 

 County Museum, Dr. Haines found a dead male wasp of the 

 same species, the other cell in this reel being empty. 



