242 ANIMAL COLOEATION. 



belonging to the genus Sesia. Not only are their wings 

 nearly bare of scales, which are so characteristic a feature of 

 the Lepidoptera, and from which indeed their very name has 

 been derived, but the colours of the body resemble those of 

 wasps, bees, and hornets. These stinging Hymenoptera are 

 not, however, the only insects which the Sesiidte superficially 

 imitate. Several of the smaller species — for example, S. tipuli- 

 formis * — are by no means unlike flies. When basking in 

 the sun upon the leaf of a currant bush, 8. fipuliformis, might 

 easily be passed over, even by a collector of little experience, 

 as a fly. This would seem decidedly disadvantageous to the 

 moth, or, at least, not positively advantageous. 



The curious likeness which certain " water flies " show to 

 moths is, if anything, probably disadvantageous to them, 

 though it is of course difficult to decide these matters offhand. 

 In any case, the brown opaque wings of the water fly must 

 render it more conspicuous than if the wings were transparent, 

 and the conspicuousness is not quite marked enough to allow 

 of the use of a_ theory of warning coloration. 



Mimicry not always Deceptive. 



Mr. Poulton found that the bee-like appearance of Sesia 

 fuciformis and S. bombyliformis did not in the least impose 

 upon a lizard, to which he offered one of these insects. It 

 was eaten " without hesitation or caution." These two insects 

 are sometimes removed from the other Clearwings and placed 



* Mr. Wallace has, however, pointed out that the resemblances of 

 Sesia tipuliformis are rather with a wasp, belonging to the genus 

 Odynems. Rogenhofer has, however, lately (Verhandl. Zool. Bot- 

 Geselhchaft, Wien, Bd. xxv.) stated that Sesia tabani/ormis mimics a 

 fly, Ceria conopoides, which is found about the same time on trunks of 

 poplar. 



