104 
A. williamsi builds a several-cell nest on small plant stems (Fig. 
50a). under a clod of earth,-ete) " As im the) first species mtmese 
are about 11-13 mm. long and more or less cylindrical. 
Both species pursue their spid- 
ers quite fearlessly and bite some 
or all the legs off before dragging 
them, beneath their body, to the 
nest. I once came across a small 
Ageniella | excitedly chasing a 
ground spider; she finally stung 
it, bit off some of the legs and 
proceeded to carry it away, wher 
I caught a glimpse of a larger 
spider dashing toward it, and then 
our wasp appeared burdenless a 
; : foot or so away. Thus the larger 
Hig. 0a. Wour-cell nest of Age. spiders do mot fear he «smaller 
niella williamsi. About natural - : 
siie. wasps, and rob them of their prey. 
So also will a larger Ageniella of 
the same species take over the pursuit and possible capture of a 
flushed spider, driving the rightful huntress away, who looks on 
while the chase is resumed. The cells of these wasps are much 
infested by an ichneumonid. 

Ageniella banoensis Rohwer. 
Length 13 mm.; grey-black, a fuscous spot on fore wing. 
Except for her double size, A. banoensis is much the counter- 
part of the two preceding species. Not so common, she has 
rather different nesting habits than either, for although a true 
architect, she builds her mud cells in a hole in the ground, thus 
perhaps doubly insuring her brood. 
On capturing a spider: she has the most exasperating way of 
lugging it about and of making lengthy stops, thus taxing one’s 
time and patience. Once, when under the shelter of a_ big 
mango tree, I noticed one of these wasps searching about a lim- 
ited space of ground; it was evident that she had already flushed 
a spider and was now trying to find the fugitive. After circling 
over the ground for some time she aroused a rather long-legged 
but small-bodied spider, which she overhauled in an open place. 
The spider was courageous, however, and showing fight, tried to 
embrace her more agile foe and to leap upon her back. This 
ageniella frustrated, and in a skirmish crippled the spider with 
a sting; then she pounced upon its back and completely quieted it 
