92 SPOLIA ZEYLANICA. 



ON A REMARKABLE MIMETIC SPIDER. 



By E. E. Green. 

 (With one Plate.) 



"TNSTANCES of protective mimicry are by no means confined to 

 -L the true {i.e. , hexapod) insects. We find the same phenomenon 

 strongly developed amongst spiders. There is, in Ceylon, a well- 

 marked group of hunting spiders (Attidce) that have acquired an 

 extraordinary resemblance to ants. This is not merely a general 

 resemblance, but the form and colour pattern of each spider can be 

 closely matched by particular species of ants. At first sight it might 

 be supposed that the mimicry was of an aggressive nature, and that 

 such spiders would habitually prey upon the ants, utilizing their 

 resemblance to approach the insects without alarming them. But 

 such is not the case ; and it is improbable that the closest superficial 

 similarity would deceive an ant which recognizes its friends and 

 foes by some other sense than that of sight. Though these spiders 

 may catch and eat an occasional ant, it is probable that the chief 

 value of the resemblance is of a protective nature. The particular 

 ants that are the subjects of the imitation are all of species that 

 have either formidable jaws and an aggressive habit {e.g. , CEcophylla) , 

 or species that are armed with a powerful sting, such as Odonto- 

 gnathus , Lohoioelta , 8ima , &c . One of these soft-bodied Attid spiders 

 would stand a poor chance in a contest with ants of the species 

 which they most resemble. 



But the object of this Note is to draw attention to a different kind 

 of spider (though also one of the Attidce) which bears the most 

 remarkable likeness, not to an ant, but to the apterous forms of 

 wasps of the family Mutillidce. 



The accompanying plate shows this similarity very clearly. The 

 spider (Figs. 5 and 6) is Cosnoptychus pulchellus of Simon, who has 

 already recorded its resemblance to a Mutilla. This resemblance is 

 so real that I was completely deceived by the first example that I 

 found. Believing it to be a Mutilla — an insect whose painful sting 

 I have personally experienced — I picked it up very carefully with a 

 pair of forceps. It was only after it had been subjected to the 

 killing bottle that I recognized its true character. Mr. Oswin 

 Wickwar tells me that he was similarly deceived by a specimen of 

 the same spider that he found at Anuradhapura, together with a 

 number of the Mutillids. He writes : " I caught one spider 

 thinking it to be a Mutillid, as it ran over the ground just like one." 



