ADAPTIVE COLORATION. 235 



FIG. 246. 



Aggressive mimicry. On the left, a bee, Bombus mastrucatus; on the right, a fly, 

 Volucella bombylans. Natural size. 



Aggressive Resemblances. The resemblance of a car- 

 nivorous animal to its surroundings may not only be protec- 

 tive but may also enable it to approach its prey undetected, as 

 in the case of the polar bear or the tiger. Among insects, 

 however, the occurrence of aggressive resemblance is rather 

 doubtful, even in the case of the leaf-like mantids, 



Aggressive Mimicry. Under this head are placed those 

 cases in which one species mimics another to which it is hostile. 

 The best known instance is furnished by European flies of the 

 genus Volucella, whose larvae feed upon those of bumble bees 

 and wasps. The flies bear a close resemblance to the bees, 

 owing to which it is supposed that the former are able to enter 

 the nests of the latter and lay their eggs. 



Alluring Coloration. The best example of this phenom- 

 enon is afforded by an Indian mantid, Gongylus gongyloides, 

 which resembles so perfectly the brightly colored flowers 

 among which it hides that insects actually fly straight into its 

 clutches. 



Recognition Markings. Though these are apparently im- 

 portant among mammals and birds, as enabling individuals of 

 the same species quickly to recognize and follow one another, 

 no special markings for this purpose are known to occur among 

 insects, not excepting the gregarious migrant species, such as 

 Anosia plexippus and the Rocky Mountain locust. 



Epigamic Colors. Among birds, frequently, the bright col- 

 ors of the male are displayed during courtship, and their evo- 



