40 BEES AND WASPS [CH. 



caterpillars, for they still retain some power of move- 

 ment they can use their mandibles and " kick " with 

 the hinder part of their body. Hence it is to the 

 advantage of the grub to retain its hold upon the 

 egg-shell and make its first meals from above, safely 

 out of reach of any too vigorous protest on the part 

 of its victims. To enable the little larva to reach 

 caterpillars rather further away than the first de- 

 voured, the egg-shell splits up to a sort of ribbon, 

 and thus increases the length of the suspensory 

 thread of which it forms a continuation. By the 

 time that the larva has eaten all the caterpillars 

 within reach of its lengthened tether it has so in- 

 creased in size and strength that it can now venture 

 to loose its hold on its safety rope and boldly eat its 

 way forward among the steadily decreasing mass of 

 caterpillars. Eventually it pupates and completes 

 its metamorphosis. 



The species of Odynerus are very subject to the 

 attacks of " cuckoos " belonging to the Chrysididae, 

 the jewel- or ruby- wasps as they are popularly 

 termed ; and also of certain dipterous flies of similar 

 habits. The careless manner in which all the Ody- 

 neri leave the mouth of their cell or burrow wide 

 open during their excursions in search of mud or 

 of caterpillars renders them easy victims to this 

 imposition. 



Our social-wasps, including the hornet, number 



