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ENTOMOLOGY 



from attack by being mistaken for its unpalatable model. The common 

 drone-fly ; Eristalis tenax (Fig. 248, B) mimics a honey bee in form, size, 

 coloration and the manner in which it buzzes about flowers, in company 

 with its model; it does not deceive the kingbird and the flicker, however. 

 Some Asilidae (robber flies) are remarkably like bumblebees in superfi- 

 cial appearance and certain Syrphus flies (flower flies) mimic wasps 

 with more or less success. The beetle Casnonia bears a remarkable 

 resemblance to the ants with which it lives. 



The classic cases are those of the Amazonian Heliconiidae and 

 Pieridae, in which mimicry was first detected by Bates. The Heli- 

 coniidae are abundant, vividly colored and eminently free from the 

 attacks of birds and other enemies of butterflies, on account of their 



.,4 



PIG. 248. Protective mimicry. ' A, drone bee, A pis mellifera; B, drone fly, Eristalis tenax. 



Natural size. 



disagreeable odor and taste. Some of the Pieridae a family funda- 

 mentally different from Heliconiidae imitate the protected Heliconiidae 

 so successfully, in coloration, form and flight, that while other Pieridae 

 are preyed upon by many foes, the mimicking species tend to escape 

 attack. 



The family Heliconiidae, referred to by Bates, comprised what are 

 now known as the subfamilies Heliconiinae, Ithomiinae and Danainae; 

 similarly, Pieridae and Papilionidae are now often termed respectively 

 Pierinae and Papilioninae. Ithomiinae are mimicked also by Papilio- 

 ninae and by moths of the families Castniidae and Pericopidae. 



The discoveries of Bates in tropical South America were paralleled 

 and supported by those of Wallace in India and the Malay Archipelago 

 (where Danainae are the chief " models"), and of Trimen in South Africa 

 (where Acraeinae and Danainae serve as models). Trimen discovered a 

 most remarkable case, in which three species of Danais are mimicked, 

 each by a distinct variety of the female of Papilio cenea (merope). 



