Transactions Texas Academy of Science. 
83 
As regards the feeding habits among solitary wasps two types may 
be recognized: first that in which the growing larva is fed by the 
mother from day to day until the larval or eating stage has passed 
and the larva has spun its cocoon and become quiescent; and sec- 
ond, the type in which the store of food is provided once for all, the 
egg laid among the provisions, the nest closed over the egg and the 
larva left to its fate. 
The Peckhams consider the habit of feeding the larva from day to 
day as the most primitive. They say : “It may be possible then that 
all wasps originally fed their young as Bembex now does and that 
while the instinct of storing the whole supply of food once for all 
was working itself out among solitary wasps, the instincts of life 
in a true society developed into those of our wasp communities.” 
Prom this point of view, Microbembex on the one hand and the 
social wasps on the other show the habit in its most primitive form 
since they not only feed their larvae until these pupate, but they 
gather almost any kind of insect food they find. The first step 
in the development among the Digger-wasps would then be the 
specialization shown in all other wasps of confining themselves to 
one kind of prey (flies, bugs, caterpillars, as the case may be). In 
this Bembex and some species of Monedula are most primitive, since 
they continue to feed their larvae from day to day. Finally comes 
the habit which obtains in nearly all solitary wasps of provisioning 
the nests once for all. This is shown in its highest form in the 
Ammophiles and Pompilides, which paralyze the caterpillars and 
spiders, store them in the nest and lay the egg upon them. In 
these cases the nest is closed long before the egg is hatched and the 
mother wasp never sees the larva. There are however, transitional 
cases between the habits of Bembex and that of Ammophila. Thus 
Monedula Carolina , the big fly catcher, closes her nest several days 
before the larva spins its cocoon, after first supplying the larva with 
a sufficient supply of food. The little bug-catcher Bembidula parata 
shows a somewhat greater difference, for while she stores her nest as 
fast as she can with very small bugs, the work is not finished until 
the larva is at least half-grown. Another instance, showing a still 
greater step in the direction indicated, is shown by an Ammophila 
urnaria described by the Peckhams. This species lays the egg on 
the first caterpillar brought in and stores the other or others as 1 soon 
as she can. In one case, the mother wasp on her return with the 
second caterpillar found a larva a day old feasting on the caterpillar 
already provided. 
It is interesting to note that, parallel with the working out of 
