of winged adults, the presence of shelter tubes over foundation 
walls, or the sudden collapse of the surface of infested wood. 
The principal food of subterranean termites is cellulose which 
they obtain from wood and other plant tissues. As a result, these 
termites are not only destructive to the woodwork of buildings, 
telegraph poles, fence posts, and other wood products, but also 
to paper, fiberboard, and various types of fabrics derived from 
cotton and other plants. Shrubs, nursery stock, ornamental plants 
and many kinds of shade trees are damaged occasionally. Trees 
killed by other insects, fire, or disease, particularly in the South, 
are attacked and the timber rendered unmerchantable unless it is 
utilized shortly after being killed. 
In attacking wood, subterranean termites feed on the soft spring 
wood only. As a result their galleries run parallel with the grain. 
These galleries are characteristically stained on the inside with 
grayish specks of excrement and earth but are free of pellets like 
those found in the galleries of nonsubterranean termites. 
Subterannean termites occur throughout most of the United 
States and in southern Canada. They are common throughout most 
of the eastern half of the United States and along the Pacific 
Coast. It is considered likely that the native species have occu- 
pied their present ranges for millions of years. In recent years, 
however, there seems to have been an increase in their de- 
structiveness northward. This has probably resulted from the 
general adoption of central heating plants in structures, from 
changes in building practices, the wider use of termite suscep- 
tible wood in construction, and from the tremendous expansion 
of suburban homes into forested areas. 
The eastern subterranean termite, Reticulitermes flavipes (Kol- 
lar) (fig. 6), one of the most destructive subterranean termites 
in eastern America, is widely distributed, occurring from the 
Gulf of Mexico north to Ontario, and from the East Coast to the 
Great Plains. Infestations normally occur in the forest where the 
dead wood of practically all species of trees is attacked. Infesta- 
tions also occur in the woodwork of buildings, in cellulose mate- 
rials stored therein, in poles and posts, and occasionally in living 
trees, shrubbery, flowers, and crop plants. 
Each colony of the eastern subterranean termite comprises 
three castes: reproductives or adults, workers, and soldiers. The 
reproductives (fig. 6A) are soft-bodied and brown or black, have 
two pairs of long, whitish opaque wings of equal size, and are 
10 to 12 mm. long. Workers, (fig 6B) are soft-bodied, grayish- 
white, and slightly less than 6 mm. long. Soldiers (fig. 6C) are 
similar to the workers except for their much larger, longer heads, 
their longer and more formidable mandibles, and their slightly 
greater length. Winged reproductives are often mistakenly iden- 
tified as flying ants. They differ from ants, however, in having 
the abdomen broadly joined to the thorax. The abdomen of an 
ant is reduced to threadlike proportions where it joins the thorax. 
The wings of ants are also transparent, and the two pairs are of 
unequal size. 
Colonizing flights occur most frequently after the first warm 
days of spring, often following a warm rain. They may also occur 
during the remainder of the warm season and sometimes even 
48 
