MIMICRY IN INSECT LIKE. 87 



MIMICRY IN INSECT LIFE, AS EXEMPLIFIED 

 BY CEYLON INSECTS."^ 



By E. Ernest Green, F.E.S., Governiuent Entomologist, 

 Royal Botanic Gardens, Peradeniya. 



With Illustrations. 



T^EFORE describing some of the more interesting instances of 

 -L^ so-called mimicry in insect life, I must ask you to disabuse 

 your minds of the idea that such mimicry is in any way conscious. 

 One frequently hears the epithets " wise," " clever," and " ingen- 

 ious " employed in connection with some particularly successful 

 case of adaptation, and it is often difficult to avoid such misleading 

 terms in ordinary conversation. 



As a matter of fact it is probable that these wonderful arrange- 

 ments of form and colour are the result of natural selection uncon- 

 sciously working upon accidental variations or mutations through 

 countless generations, those favourable to the organism having the 

 better chance of being perpetuated and accentuated. 



The word " mimicry " itself is unscientific in this connection, but 

 is the term that has been generally adopted for the phenomena 

 in question. 



In studjong animal mimicry, two main classes or purposes may be 

 at once distinguished, ■protective and aggressive, though the latter 

 may — and often does — serve both purposes. Protection may again 

 be subdivided into 'protective resemblance, where the insect simulates 

 some inanimate object, and protective mimicry proper, in which the 

 insect assumes the appearance of some other species that is naturally 

 protected either by some weapon, such as a poisonous sting, or by 

 some unpleasant taste or odour. Of the former class — protective 

 resemblance — we have abundant beautiful instances in Ceylon. 

 The best known is that of the leaf insects. 



[Fig. 1.) Our more common Ceylon species {PulchriphylUum 

 crurijolium) carries its disguise throughout every stage of its 

 existence. The eggs are remarkably like the seed of some plants, 

 and they are shed upon the ground, and lie amongst the dead leaves 

 just as might the seeds of any tree. I must confess that I have 

 never found the particular seed that matches them, but I am con- 

 fident that such exists. If I were to send a packet of these eggs to 



* This article is the substance of a lecture delivered by the author in 

 Kandy in 1907. 



