544 
Saw-flies, Gall-flies, Ichneumons, 
first described as members of new genera. A flourishing Eciton colony 
may comprise several thousand individuals. 
Interesting and common Myrmicids are the little Cremastogasters, of 
which one of the most abundant Eastern species is C. lineolata , the shed- 
builder ant. It is a small black and yellowish-brown species, the workers, 
measuring from \ to T 3 g- inch in length, which usually lives in nests in 
decaying logs or stumps or in the ground under stones. But sometimes it 
builds a nest out of chewed wood, like a large rough gall attached to some 
bush above ground. Atkinson describes such a nest (Fig. 748) 18 inches long 
and 12 inches in circumference which contained adults, larvae, and pupae. 
In addition to these nest-sheds, small temporary sheds are sometimes built 
at some distance from the nest “over the herds of Aphids, or scale-insects, 
from which they obtain honey-dew.” 
Another interesting and abundant Myrmicid is the minute yellow “thief- 
ant, ” Solenopsis molesta. Although it sometimes lives in independent nests, 
more often by far it is to be found living in association with some larger ant 
species—it consorts with many different hosts—feeding almost exclusively 
on the live larvae and pupae of the host. The thief-ant is so small and obscurely 
colored that it seems to live in the nest of its host practically unperceived. 
The Solenopsis nest may be found by the side of the host-nest, around it, 
or partly in it, the tiny Solenopsis galleries ramifying through the nest-mass 
of the host, and often opening boldly into these larger galleries. Through 
their narrower passages, too narrow to be traversed by the hosts, the tiny 
thief-ants thread their way through the other nest in their burglarious excur¬ 
sions. 
As an example of Myrmicids which live in compound or mixed nests the 
species Myrmica brevinodes , a common red-brown ant that lives under stones 
in the East, and the smaller Leptothorax emersoni may be referred to. 
The interesting symbiotic life of these ants has been studied and carefully 
described by Wheeler (. American Naturalist , June, 1901). The little Lep¬ 
tothorax ants live in the Myrmica nests, building one or more chambers with 
entrances from the Myrmica galleries, so narrow that the larger Myrmicas 
cannot get through them. When needing food the Leptothorax workers 
come into the Myrmica galleries and chambers and, climbing on to the backs 
of the Myrmica workers, proceed to lick the face and the back of the head 
of each host. A Myrmica thus treated “paused,” says Wheeler, “as 
if spellbound by this shampooing and occasionally folded its antennae as if in 
sensuous enjoyment. The Leptothorax, after licking the Myrmica’s pate, 
moved its head around to the side and began to lick the cheeks, mandibles, 
and labium of the Myrmica. Such ardent osculation was not bestowed in 
vain, for a minute drop of liquid—evidently some of the recently imbibed 
sugar-water—appeared on the Myrmica’s lower lip and was promptly lapped. 
