ii6 



INSECTS 



alyzed by stinging the nerve-centres and then retain 

 life enough to remain without decaying until the wasp 

 larva has reached maturity. One of the commonest 

 examples of this sort is seen in the shapeless cell made 

 by our blue mud-wasps under porches, between the 

 slats of shutters, under the eaves or even in garrets. 

 If we open one of these cells in summer we find it stored 

 with small motionless caterpillars or spiders, and either 

 an egg or an actively feeding wasp larva among them. 





Fig. 56. — A potter-wasp, Eumcnes fratcrna, at a. its cell b broken open at c, to 

 show stored caterpillars. 



On the same order, but much more neatly built, are 

 the mud cells of the potter- wasps, which we find fre- 

 quently attached to low bushes. These are usually 

 filled with small caterpillars, all very much of a size, 

 and so closely packed as to fill the cell completely. 

 As every one of these cells requires from ten to twenty 

 larvae to fill it and a single wasp makes a dozen or more 

 cells, the number of specimens thus used up becomes 

 quite a factor. Not all wasps feed on caterpillars; in- 

 deed, there is scarcely an order that is not fed upon. 

 Some digger-wasps fill their cells with grasshoppers; 

 others, that make their cells in the hollow shoots of 



