i H.\l\ XXI. 



BENEFK I \l [MSB! rS 



i<>; 



and store up caterpillars as food for their young. Of this latter 

 i lass the large long-waisted spe< ies ol Eumenes are common visi- 

 tors to almost every bungalow, building neat mud-cells, provided 

 with a regular neck and lip like a water-jar, in which caterpillars 

 tored, the egg deposited, and the coll scaled and left. It is 

 remarkable with what regularity and consistency the wasp hunts 

 tor and succeeds in capturing caterpillars of the same species and 

 size, and it seem-- probable in some cases that all the caterpillars 

 brought and stored are members of one brood which have been 

 systematically hunted down and destroyed ; so that the good 

 accomplished bj these wasps is tar greater than is generally 



Fli in va 



extracted IV a mud-cell of 



Eumenes conica, (< original.) 



Eumenes conica, a 

 i immon Cell-building Wasp. 

 a Iriginal.) 



realized. The caterpillars are stung before they are placed in the 

 cell and as a result they remain practically helpless, alive but 

 incapable of co-ordinated motion. A great deal has been written 

 regarding the " wonderful instinct which always impels the wasp 

 to deliv er its sting in one and the same and most effective portion of 

 the nervous system of the caterpillar," but this is largely an effort 

 of the imagination, and ever) gradation can be found in stung 

 larva; between complete paralysis anil ineffective and transient 

 results; sometimes, indeed, the caterpillar may even pupate and 

 as a moth. The wasp's egg is suspended from the top ol 

 the cell by a slender filament, so that it , s less exposed to danger 

 bj any convulsive movements of the stored caterpillars; on hatching 

 it devours these, still living, until they are all eaten, when it 

 pupates in the cell and ultimately emerges. The number oi cater- 

 pillars stored depends upon their size ; in the case of moderate- 

 sized "ins {e.g., Pllisia) about seven are stored in each cell as a rule 

 wasp may build and store eight or ten cells in one cluster 

 and probably builds and stores several clusters. So it will be seen 

 that every single one of these wasps may be c alculated as a poten- 

 tial destroyer of at least one hundred Caterpillars, and SUCh wasps 

 should, therefore, be protected and encouraged as much as possible. 

 Wasps are peaceable creatures if they are left undisturbed and 



