Imported fire ant mounds are found in almost all kinds of soil, 
but most commonly in open areas. Few if any are ever found in 
heavily timbered areas, especially in hardwood stands. An average 
mound is about 1 foot high and 2 feet across; some are up to 3 
feet tall. The larger ones are usually dome-shaped or conical, and 
may contain more than 100,000 ants. In heavily infested areas 
there may be more than 60 nests per acre. Nests also are found 
in rotting logs, around tree trunks, and occasionally under build- 
ings. Green (312) discussed the biology of this species. 
For more comprehensive treatments of ants, the reader is re- 
ferred to publications by Wheeler (759), Smith (659), and 
Creighton (174). 
SUPERFAMILY VESPOIDEA 
This superfamily is comprised of two families, the Vespidae and 
the Pompilidae. Many species are social in habit and live together 
in colonies; others are solitary and live alone. The adults gener- 
ally feed on nectar, sap, or similar materials, whereas the larvae 
feed on other insects or spiders. A few species are of some impor- 
tance as pests of forest or shade trees; quite a number of others 
may create problems when they occur in abundance in picnicking 
areas, campgrounds, or other recreational areas. 
FAMILY VESPIDAE 
HORNETS, YELLOW JACKETS, AND POTTER WASPS 
The family Vespidae contains the well known stinging wasps, 
hornets, and yellow jackets. More than 350 species have been re- 
corded in North America north of Mexico, about one-third of 
which occur in eastern United States. Considered as a whole, 
these insects are not very important as forest pests since very 
few of them are capable of inflicting serious injury to trees. 
Adults of the family differ considerably in size and appearance, 
but all are distinguished by the very long discoidal cell in the 
forewing, and by their common habit of folding their wings 
longitudinally while at rest. Some of the more common species 
live in nests or colonies containing a few to several hundreds or 
thousands of individuals. Bohart (87) published a synoptic cata- 
log of species occurring in America north of Mexico. 
Social species construct nests out of papery material consisting 
of wood or foliage chewed up and elaborated by the insect. Hornet 
nests contain several to many tiers of hexagonal cells enclosed in 
a papery envelope and are usually attached to the limbs of bushes 
or trees or to the eaves of buildings. They are roughly spherical 
in shape and are often quite large, measuring several inches in 
diameter. Yellow jackets also construct nests of papery material, 
but these are usually placed out of sight in the ground, in stumps, 
or under objects. An exit hole leads to the outside. Wasp nests 
usually consist of a single horizontal comb or layer of cells at- 
tached to a support by a slender stalk. They may be found in all 
sorts of places such as under the eaves of roofs, under porches, in 
493 
