900 PEOCEEDIXGS OF THE THIRD ENTOMOLOGICAL MEETING 



clinging around the hole tlirough which the caterpillar had been dragged 

 and this accounted for the collection of debris seen in the previous shells. 

 This iacident was not an isolated one, for it was seen repeated on several 

 occasions and at other times spiders were detected in the act of devouring 

 larvae a few days old. The destruction of the Sphingid larvse therefore, 

 before even they leave the ova. works out at 86 per cent, and probably 

 another 10 per cent, are destroyed by the same agency in the first week 

 or two of larval life. I do not think the larger larvae suffer much from 

 the attacks of spiders but as their number is still further reduced by 

 preying Hymenoptera and birds, not much more than one or two per cent, 

 can come to maturity. The above-mentioned larvae are not the only 

 species which are attacked in the egg stage for I have noticed that 

 the Papilioninse are also checked in a similar way, P. jjolytes for instance. 

 For some time I was under the mistaken impression that the empty eggs 

 were sterile ones but the above observations furnished the key to the 

 truth. The deposition of sterile eggs in nature I imagine must be very 

 rare. 



It may be noted here that spjiders never attack those larvae which are 

 protected by ants and if one be placed on a bush inhabited by such, 

 it will beat a hasty and ignominious retreat, always provided that it is 

 able to escape the furious onslaught of the protecting hordes. 



59.— THE COMPARATIVE INVISIBILITY OF PAPILIO DEMO- 

 LEUS DURING FLIGHT. 



By E. H. HANKIN, M.A., Sc.D., Chemical Examiner to Government, 

 United Provinces. 



It is possible that the following remarks on the colouration of a butter- 

 fly, Papilio demoleus. may be of interest from the point of view of 

 the application of colours for use in camouflage, with especial reference 

 to the painting of military aeroplanes so as to secure invisibility when 

 seen from below. 



Since it was proved, some years ago, that the decoration of butter- 

 flies has nothing to do with sexual attraction, no satisfactory explanation 

 has been put forward as to its nature. In some cases there can be no 

 doubt that it serves the purpose of concealment. In other mstances 

 it warns enemies of the unpalatability of its possessor. Neither of these 

 exijlanations will apply to P. demoleus. 



This butterfly in size and colouring has a superficial resemblance to 

 the English Swallow-tail butterfly. In freshly-hatched specimens the 

 upper surface of the wing has a chequer pattern of black and primrose 



