150 A BOOK OF INSECTS 



bylans, appears regularly each year in two forms, one 

 black and red, the other black and yellow, each form 

 bearing a close resemblance to a distinct species of humble- 

 bee. Again, the familiar bee-flies (Bombijlhts) are verit- 

 able " doubles " of small brown humble-bees, while the 

 so-called drone-fly (JEristaUs tenax) is a creditable replica 

 of the hive-bee. All these examples of mimicry, and 

 many others, may be observed within the confines of the 

 British Islands. The case of the drone-fly and the hive- 

 bee is in some ways unique, because the latter is among 

 the very few protected insects that are not strikingly 

 coloured. We must not forget, however, that the hive- 

 bee is supremely successful and self-assertive, while its 

 sting is even more deadly than the wasp's. Thus, it is 

 not surprising that the bee is recognised and avoided, its 

 sober livery notwithstanding, or that it has become a 

 model for mimicry. Professor Lloyd Morgan found that 

 young birds, having tasted worker hive-bees and rejected 

 them with disgust, subsequently refused to touch not 

 only drones, which have no stings, but also the mimetic 

 drone-flies. 



Bees and wasps are also mimicked by beetles. A 

 curious species called Emus hirtus, which is allied to the 

 familiar " devil's coach-horse," is thickly clothed with 

 long, yellowish hairs, and looks exactly like a humble-bee 

 when on the wing. Like its model, it loves to fly in the 

 hot sunshine, instead of skulking under stones and refuse 

 after the manner of its kith and kin. This beetle is very 

 rare in England, though common on the Continent ; but 

 we have our own wasp beetle (Clytus arietis) which is 

 very abundant in flowers during the early summer. It is 

 a member of the great " long-horn " family (Cerambycidcs), 

 and some of its tropical cousins are among the most 

 remarkable mimics known. Like the clear-wing moths, 



