Wasps, Bees, and Ants 
545 
up by the Leptothorax. The latter then dismounted, ran to another Myrmica, 
climbed onto its back, and repeated the very same performance. Again it 
took toll and passed on to still another Myrmica. On looking about in 
the nest I observed that nearly all the Leptothorax workers were similarly 
employed.” Wheeler believes that the Leptothorax get food only in this 
way; they feed their queen and larvae by regurgitation. The Myrmicas 
seem not to resent at all the presence of the Leptothorax guests, and indeed 
may derive some benefit from the constant 
cleansing licking of their bodies by the sham- 
pooers. But the Leptothorax workers are careful 
to keep their queen and young in a separate cham¬ 
ber, not accessible to their hosts. This is prob¬ 
ably the part of wisdom, as the thoughtless 
habit of eating any conveniently accessible pupae 
of another species is wide-spread among ants. 
The third family, Camponotidae, a large one, 
includes a majority of the familiar ants of 
eastern North America. The large black car¬ 
penter-ant, Camponotus pennsylvanicus (Fig. 
749), which builds extensive nests in logs, 
stumps, building timbers, and even living trees; 
the large black-and-red mound-builder, For¬ 
mica exsectoides , whose ant-hills are from five to 
ten feet in diameter; and Lasius brunneus , the 
little brown ant “ whose nests abound along the 
borders of roads, in pastures, and in meadows,” 
are all familiar Camponotid species. The last- 
named one is known in the middle states as the 
corn-louse ant because of its interesting associa¬ 
tion with the wide-spread corn-root louse, A phis 
maidi-radicis. In the Mississippi valley this 
aphid deposits in autumn its eggs in the ground 
in corn-fields, often in the galleries of the little brown ant. The following 
spring, before the corn is planted, these eggs hatch. Now the little brown 
ant is especially fond of the honey-dew secreted by the corn-root lice. So when 
the latter hatch in the spring, before there are corn-roots for them to feed 
on, the ants with great solicitude carefully place them on the roots of cer¬ 
tain kinds of knotweed (Setaria and Polygonum) which grow in the field, 
and there protect them until the corn germinates. They are then removed 
to the roots of the corn. 
A curious Camponotid is the honey-ant, Myrmecocystus melliger , found 
in the southwestern semi-arid states. McCook studied these ants in the 
Fig. 749. —Galleries and cham¬ 
bers in wood of the Eastern 
large black carpenter-ant, 
Camponotus pennsylvanicus. 
(After McCook.) 
