PKOTBCTIVB MIMICEY. 225 



resemblance between the two creatures is simply and wholly 

 accidental." 



Mimicry of Hymenoptera by Volucella is Difficult to Account for. 



One of the most singular cases of apparent mimicry among- 

 British insects is that of the flies belonging to the genus Volu- 

 cella and humble bees or wasps. They were first studied by 

 Reaumur, who spoke of them as "Z>es mouches <l deux ailes qui 

 ont Vair cVabeilles^'' Mr. Lloyd Morgan, in his recently published 

 volume, "Animal Life and Intelligence," gives illustrations of 

 the two insects side by side, which show this resemblance very 

 well. I have also had reproduced upon plate IV. a group of bees- 

 and Volucellce in the Natural History Museum. It is a long- 

 time since this case of mimicry was first pointed out. Kirby 

 and Spence * remark upon the probable advantage which the 

 flies get by being able to deposit their eggs in the nest of the 

 humble bee without arousing the suspicions of their involuntary 

 hosts. " Did these intruders venture themselves amongst the 

 humble bees in a less kindred form, their lives would probably 

 pay the forfeit of their presumption." 



The example of mimicry afforded by these VolucellcB is one 

 of the strongest that has been put on record ; it would be 

 more remarkable still were some others of the hive parasites 

 protected in a similar way. The two moths Galleria cerella 

 and Aphomia sociella, which also lay their eggs in hives, are 

 not in the least degree like the insects which they attempt to 

 rob : but it may be urged, perhaps, that the disguise is not so 

 necessary in their case, because they enter under cover of the 

 twilight. 



This moth is by no means confined to English bees ; Messrs. 

 Home and Smith t describe the occurrence of a Galleria in 



* "Introduction to Entomology." t Trans. Zool. Soc. ,Yo\.i\. 



15 



