III. BEMBEX TEXANUS CB. AND MICROBEMBEX MONO- 
DONTA, SAY. 
Microb emb ex and Bembex (Fig. 2) are both common in the 
sandy woods, where they often form large mixed colonies, build- 
ing their nests side by side in great numbers. When a novice first 
comes upon one of these populous colonies on mid-day, when busi- 
ness is at its height, he is bewildered by the great number of wasps 
engageddn the general hubbub around the many holes that riddle 
the ground (Fig. 24). What confuses him more than anything 
else is the presence of the two kinds of wasps that look and act so 
much alike. Gradually, however, he becomes accustomed to the 
sight and soon begins to be able to distinguish easily the two species 
as they rest on the ground. 
Microb emb ex monodonta is somewhat smaller and more slender 
than Bembex Tex. and the stripes across her abdomen are greenish 
yellow, while those of Bembex are yellowish blue. With practice 
one soon learns to distinguish the two species at a glance, by their 
actions as well as appearance. The manner of flight is charaeter- 
istive in each case. Bembex, as she flies around, is always in a 
hurry, flying in a zigzag course and giving a buzz at each sudden 
turn like a blue-bottle fly. Microb emb ex is calmer in her move- 
ments, she never seems in a hurry but flies gracefully about like a 
bird skimming the water. Particularly on the hunt, as will be 
pointed out below, is the diffeffrence very marked. Often while 
digging in front of the nest the wasps will rise and leave their work 
for a moment, especially if disturbed by idlers flitting leisurely 
about. Bembex Tex. usually settles immediately to resume work, 
but Microb &mbex considers the interruption an opportunity to take 
a few moments of well-earned rest and bask a while in the sun- 
light. 
Both of the species under consideration go through about the 
same actions in digging at their nests, the only difference being 
the quicker and more nervous ways of the smaller species. Here 
we notice the manner of digging in general characteristic of all 
the Bembecids. The body of the wasp, balanced, as it were, on 
the middle pair of legs, represents a teeter-totter in miniature. 
Eiach time the head goes down, the tail bobs up and a stream of 
sand pours out from under the wasp, propelled by several smart 
