VARIOUS MIMICS OF WASPS 251 



A superficial resemblance to stinging Hymenoptera is 

 probably more general and is brought about by smaller 

 changes in Diptera than in any other Order of insects. 

 A fly which gains alternate black and yellow rings on its 

 body is at once suggestive of an appearance presented by 

 many common wasps. In more extreme cases, the body 

 gains a constriction presenting a strong likeness to the 

 slender petiole of the wasp's abdomen, there are changes 

 in the manner of folding and sometimes in the colour of 

 the wings, in the buzz, in the movements of the body 

 (the latter being such as to suggest the power of stinging), 

 and (when the humble-bees are mimicked) in the acquisition 

 of an abundant hairy covering. 



A Hemipterous insect or bug requires the most pro- 

 found modification in the shape of its flattened un-wasp- 

 like body, and in the display and characteristics of its 

 wings. Corresponding to these much greater initial 

 differences, the resemblance is rarer than in Diptera. 



A Lepidopterous insect requires above all to gain 

 transparent wings, and this in the most striking cases 

 that have been studied is produced by the loose attach- 

 ment of the scales, so that they easily and rapidly fall ofl' 

 and leave the wing bare except for a marginal line and 

 along the veins {Heniaris, Trochilhnii). In other cases 

 again (certain Sesiidae) the scales may remain on the wing, 

 but themselves become transparent. In the numerous 

 more perfect instances the body is banded, and may gain 

 a marked 'waist', while the scales upon it may be lost or 

 modified, so that the appearance of the hard shining body 

 of the model is suggested with extraordinary exactness. 



The means adopted among Coleoptera, even in closely 

 related genera, are so curiously different that a longer 

 description is necessary. 



The following examples are all selected from the 

 Longicorns. The simplest resemblance to a wasp is that 

 attained by the common beetles of the genus Clytits, such 

 as the British C. arietis, the 'Wasp-beetle'. In these 

 cases there is nothing visible to represent the wings of 

 a wasp ; but the elytra and thorax are black banded with 

 yellow^, there is a far more pronounced ' waist ' than is 



