242 ANIMAL COLORATION. 



belonging to the genus Sest". 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 Sesiidse superficially 

 imitate. Several of the smaller species for example, S. tip til i- 

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

 the sun upon the leaf of a currant bush, S. tipuliformis, might 

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

 as a flv. This would seem decidedlv disadvantageous to the 



v . O 



moth, or, at least, not positively advantageous. 



The curious likeness which certain " water flies " show to 

 moths is, if anything, probably disadvantageous to them r 

 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 Sestet 

 fuel for mi 8 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 

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

 Odynerus. Rogenhofer has, however, lately (VerTiand-L Zool. Bot- 

 Gesellschqft, Wien, Bd. xxv.) stated that Sesia tabaniformis mimics a 

 fly, Ceri a conoj>oides, which is found about the same time on trunks of: 

 poplar. 



