1915] The Ottawa Naturalist. 75 



tion, will lie prone on its side; moths, too, will mimic death by 

 lying on their backs. Beetles will feign death in the same way. 



Battle within battle must, Darwin says, throughout nature, 

 be continually recurring with varying success. The weak suffer 

 at the hands of the stronger, and they, having no other means of 

 protection against a stronger enemy, have recourse to various 

 strategies. If the caterpillar does not exhibit the protective re- 

 semblance, it may be it is unnecessary, that there are other means 

 of protection existing. There are, for instance, many caterpillars 

 that may be said to be quite conspicuous by their brilliant colour- 

 ing. But no bird will touch them. Their safeguard, no doubt, 

 is that they taste nasty, and their bright colours thus serve to 

 protect them. Other forms of insect life escape elimination 

 through the development of offensive weapons, such as the sting 

 of wasps and bees. Animals which prey upon these forms learn 

 to avoid them, and thus it becomes an advantage to other insects 

 not possessing such means of protection to mimic them. And 

 so we have that venomous-looking insect the great Sirex gigas, 

 and the clear-wing hornet moth, Sphecia apiformis, with its abdo- 

 men arrayed in the bright colours of the hornet, and its sting-hke 

 projection and ovipositor. Yet this is a quite inoffensive and 

 harmless insect. 



As in the case of protective resemblance, so too, in its aggres- 

 sive correlative, the resemblance may be general or special, or 

 may reach the climax of mimicry. Hence, what may serve as 

 a protective resemblance, may also enable the prey to steal upon 

 its enemy. The ctickoo bee Psithyrus rttpestris, an idle queen, 

 who collects no pollen, and has no pollen baskets, steals into the 

 nest of the bumble bee and there lays her eggs. So great is the 

 resemblance here, that not only is the mother bee able to enter 

 the nest unchallenged, but the young bees when hatched are by 

 the same means enabled to escape. Our various bumble bees, 

 no doubt, find great advantage in so closely resembling one an- 

 other. Many other insects, too, find eqtially great advantage 

 in so closely resembling the bumble bees. Many common flies 

 mimic them, and each colour type of bumble bee has its appro- 

 priate mimic. Certain bees, called Apathi, are parasitic in the 

 nests of the bumble bees. They are indeed very much like real 

 bumble bees, from which they may be distinguished by the thin-^ 

 ness of their fur and the consequent shining appearance of their' 

 bodies. These very large bees have precisely the colouring of the 

 true bumble bees. Some are parasitic in the nests of those bees 

 which they resemble in colour, and it may be that this resemblance 

 assists them in entering the nests. Hence, it would seem that 

 the mimicry is not so much an aid to the imposition upon the 

 bumble bees, as a means of protecting the Apathi from the general 



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