MIMICRY IN INSECT LIFE, . 91 



that had once been stung by a wasp would instinctively avoid 

 another insect similarly coloured. We consequently find that many 

 harmless insects have acquired this type of marking, and so escape 

 molestation by their resemblance to their self-protected models. 

 Thus, there are certain moths and flies with banded bodies, and 

 beetles in which the same pattern is produced on tlie closed wing 

 cases. Even members of the spider tribe have found the advantage 

 offmimicking better protected insects. That very pugnacious 

 insect, the "red ant" ((E'copAyZZa), is naturally protected not only by 

 its powerful jaws, but by the copious secretion of pungent formic 

 acid, which renders it obnoxious to most insectivorous creatures. 

 It is imitated both in form and colour by several other insects, more 

 especially by a slender " hunting-spider." So close is this resem- 

 blance that most persons to whom I have pointed out the spider 

 have declared unhesitatingly that it was verily tlie red ant itself. 

 We have in Ceylon a whole series of such ant-hke spiders, each 

 apparently modelled upon some particular species of ant. Spiders 

 are possessed of eight legs, while ants have only six apiece ; but this 

 does not interfere with the resemblance, for the first pair of the 

 limbs of the spider take the place of the antennae of the ant. The 

 deception is only noticeable when the sjaider becomes alarmed by a 

 close inspection and lets itself down by a silken thread — a feat that 

 is impossible to any kind of ant. 



While on a recent tour in the neighbourhood of Trincomalee I 

 saw^on the ground what I supposed to be a species of Mutilla — a 

 peculiar genus of wasp, the females of which are apterous and 

 brilliantly coloured. Knowing that these insects are armed with a 

 powerful sting, I was careful to pick it up with a pair of forceps, and 

 it was not until I had bottled it that I realized that my capture was 

 of much greater interest, it was a species of spider that had adopted 

 the characteristic form and colouriag of a Mutilla. I subsequently 

 captured a second specimen, of the opposite sex, which apparently 

 mimicked yet another species of Mviilla. 



Large groups of insects, containing many widely distinct species, 

 genera, and even families, are sometimes found to have acquired 

 a type of coloration and pattern common to all of them. Such an 

 association is distinguished by the term " Miillerian," after the 

 famous naturalist (Fritz Miiller) who first drew attention to the 

 phenomenon. Each individual of such a group is usually itself 

 protected by some disagreeable property, but by their common 

 likeness to each other it is supposed that they contribute to the 

 safety of the other members. This may require a little explanation. 

 Every animal has to learn for itself what is good, wholesome food, 

 and what is injurious or distasteful. An inexperienced young bird 

 or lizard would not know that a certain gaudily coloured insect 

 had an unpleasant taste until it had discovered the fact by actual 

 experiment. But once learned, the lesson is never forgotten. The 



