54i 
Wasps, Bees, and Ants 
Fig. 744. —A Ponerine ant, Leptogenys 
elongata. (After Wheeler; enlarged.) 
to quantity and time. If the regulation by the workers of the kind and 
quantity of food given the larva is the cause or one of several influencing 
factors in determining the caste or kind of individual into which the larva 
shall develop, as is believed by most 
students of social insects, then the 
unmanipulated food of the Ponerine 
larvae and the inequality of its con¬ 
trol as to quantity and time of feed¬ 
ing may explain how it is that the 
caste distinctions are so much less 
marked in this primitive ant family 
than in the Myrmicidae and Campo- 
notidae, where, as we shall see, the 
character and amount of the food 
given the larvae is carefully controlled 
by the workers. 
The family Myrmicidae includes a 
large number of our most interesting 
ants; almost all are stingers, and all are readily distinguished from members 
of either of the other families by having the basal two abdominal segments 
knot-like, and forming the peduncle. Some of the Myrmicids are well 
known because of their abundance, wide distribution, and troublesome ten¬ 
dency to invade our houses, like the common little red ant, Monomorium 
pharaonis , while others are familiar through the accounts which have been 
written by various authors of their specialized 
habits. Among the latter are the harvesting or 
agricultural ants (Pogonomyrmex), a single species 
of which, the large harvester of Texas, P. barbatus 
var. molijaciens , has had a three-hundred-page 
book devoted to it, and the fierce marauding ants 
of the genera Eciton and Atta best known through 
certain famous tropic kinds, but represented in this 
country by several thoroughly interesting and char¬ 
acteristic species. 
Nine species of harvesters (Pogonomyrmex) (Fig. 
745) occur in this country (in the southern, south¬ 
western, and Pacific coast states) all (except one 
small retiring species) as far as known forming small or large communities 
in nests partly underground and partly heaped up in conspicuous mounds 
(Figs. 746 and 747) in open, sunny, and usually grassy places. They live 
specially abundantly in the great western plains and indeed in nearly desert 
regions. Into the nest they bring great stores of seeds and grains, gathered 
Fig. 745. —An agricultural- 
ant worker, Pogonomyr¬ 
mex imberbicolus. (After 
Wheeler; much enlarged.) 
