THE STINGING HABIT IN WASPS. 22a 



Crabronidae the two species with which we are familiar almost 

 invariably store up flies that are killed before they are brought 

 into the nest; our common Diodontus, as well as our Stigmus, 

 stores up dead aphides; Rhopalum stores dead gnats; Oxybelus 

 and Bembett kill their flies; nearly all of the beetles taken by 

 our Cerceris were dead, there being in all these cases an occa- 

 sional exception, one out of twenty-five or thirty being left alive. 

 Astata 'bicolor kills at least half of her bugs before storing 

 them. Turning to the spider hunterd the French Pelopaei are 

 always obliged, according to Fabre, to content themselves with 

 cadavers, while ours killed most of their spiders in stinging 

 them and packing them away, and so many more died shortly 

 after the nest was sealed that by the time the egg hatched not 

 more than a third were still alive. It has been supposed that 

 with these Pelopaei, the wasp mother protected her nurslings- 

 from the evils of unwholesome diet by laying up large numbers 

 of small spiders instead of a few large ones, the process of de- 

 composition being hastened after a break has been made in the 

 skin. Agenia bombycina deliberately breaks the skin of the 

 one large spider which she places in her cell, by cutting off all 

 the legs to make it fit better. Her young are certainly fed 

 upon dead matter since even if the spider survived her sting it 

 would die under this severe operation. Our little friend, the 

 tornado wasp, gives her offspring but one spider, and this at 

 the moment of its entombment is quite as often dead as alive. 

 Pompilus marginatus uses the same method, killing as fre- 

 quently as not, and with both of the spiders that we saw taken 

 by Salius the sting proved fatal. As has been said Ammophila^ 

 the most skillful operator of all, stings her caterpillars in so un- 

 certain and variable a manner that many of them die before 

 they are attacked by the larva. It must be acknowledged that 

 if the wasps are really aiming to produce a state of paralysis, 

 and especially if they are trying for even results, they are one 

 and all of them in the novitiate state, and are not as yet entitled 

 to rank as masters in the art. However this inference as to 

 what they are striving for is purely gratuitous since there is 



