THE EUMENIDAE 



327 



The question arises apropos of this ; does the acid of the 

 sting serve in any way as a preserving fluid to keep the 

 flesh in good condition? For certainly if we were to gather 

 these caterpillars and shut them up without food they would 

 starve to death and putrefy long before the length o-f time 

 noted above had elapsed. 



The delicate little egg is suspended by a short silken 

 thread from the top or wall of the cell. Fabre would have 

 us believe that this ingenious contrivance saves the egg from 

 being crushed among the mass of heavy, writhing cater- 

 pillars in the lower part of the nest. This explanation ap- 

 pears very plausible, but we have found repeatedly that this 

 protection is not absolutely necessary, for we have reck- 

 lessly removed the egg from the cell and dropped it into 

 a mass of squirming caterpillars in a vial; these eggs have 

 always hatched and made thrifty larvae, often growing to 

 adulthood. Although the tiny thread appears very delicate, 

 it is astonishingly strong. 



* * 



FIG. 64. After the feast. Empty heads of Pholisora catullus cater- 

 pillarsall that the Odynerus infant leaves. 



By the day following oviposition, the egg has enlarged to 

 twice its size and is of a golden yellow color, and usually it 

 hatches on the second day. The little larva is then about 

 10 mm. in length, with transparent body walls and clear pale 

 green contents, a very pretty little organism. It drops down 

 upon the caterpillars and greedily devours them, one after 



