TRACHEATA 38 
Go 
males, females, and workers; the last-named are females which 
sometimes produce parthenogenetic eggs. These colonies are 
Fic, 216.—Nest of Vespa sylvestris. 
annual, existing for the summer only. In the autumn all die, 
with the exception of a few fertilised females, which creep into 
crevices of trees or under stones, 
and hibernate through the winter. 
In the spring the female emerges 
and commences to build a nest; 
this is constructed of fragments of 
wood gnawed up and mixed with 
saliva, the whole making a papery 
substance. As soon as two or 
three cells are finished the female Bias ole Vesparuja. 
lays an egg in each, and when the 
white apodal grubs hatch out they have to be fed, whilst at 
the same time the mother is widening and deepening their 
cells and adding others. 
The larval stage lasts about two weeks, and then the grubs 
