THE STINGING HABIT IN WASPS. 225 



her young. * * * A millimeter upward kills, a millimeter 

 downward paralyzes on this slight inclination depends the race 

 of Scolia." 



As a striking example of the wonderful precision and discrim- 

 ination practiced by wasps in stinging their prey Fabre cites 

 Philanthus apivorus which, by a single stroke in the cervical 

 ganglion, inflicts death so suddenly that every muscle is relaxed. 

 If this manoeuvre were not performed with accuracy the wasp 

 would be unable to suck the honey from the dead bee; and if 

 the honey were left in the bee it would harm the larva for which 

 the victim is destined. The utility of the whole performance 

 rests upon the pernicious action of honey as food for young 

 wasps, and Fabre has done what he can to test this point by feed- 

 ing the larvae upon bees from which the honey was not removed, 

 as well as upon honey alone, with the result that when thus 

 treated they invariably died. But larvse under artificial condi- 

 tions die from all sorts of causes and we cannot but feel that he 

 has been too ready to draw his conclusions when we find that 

 the young of Cerceris ornata, observed by Marchal, thrive upon 

 bees from which the honey has not been removed. 



The sting in both bees and wasps, was originally an ovipos- 

 itor and even today, in the egg bearers, its most important uss 

 is to direct and place the newly laid ovum. There can be little 

 doubt that its character as a weapon of offense and defense has 

 been added later to its primary use. In the social wasps as well 

 as in the social and solitary bees, its use is confined to defensive 

 operations, even such genera as Polistes and Vespa, that feed 

 their young on animal food, not bringing it into play to aid 

 them in the capture of prey, since they have sufficient weapons 

 in their strong mandibles. Moreover, it is probable that there 

 are many solitary wasps that never sting their victims. If, in 

 the nest of Bembex, flies are found that have survived the 

 squeezing of the thorax, no one suggests that there is anything 

 mysterious or remarkable in the matter, but let another wasp 

 subdue its victim by means of the sting instead of the mandi- 

 bles and we overlook the explanation, so near at hand, that all 

 15 



