INSECT ENEMIES OF EASTERN FORESTS 625 
ants will track through it and carry it to all parts of the nests, whereas 
the spread of liquids and gases is often blocked in the tortuous, partly 
frass-filled galleries. Friend and Carlson (170) recommended con- 
trolling colonies in telephone poles by injecting into the nests coal-tar 
creosote diluted with an equal volume of gasoline. This is accom- 
plished by boring a hole through the upper part of the nest and in- 
jecting the material with a grease gun. Not less than 1 pint should 
be injected into a cavity 4 feet or less in length and not less than 2 
pints into cavities 4 to 7 feet long. Downes (140) reported excellent 
results in controlling carpenter ants with derris powder (4 percent 
rotenone). No matter where the nest is located or how extensive the 
infestation, if the powder can be placed where the ants must walk 
through it and thus get some of it on their bodies, the colony may be 
exterminated rapidly. A valuable aid in obtaining a good distribu- 
tion of the dust is the use of an applicator consisting of a bulb (8- 
ounce capacity) having a cone-shaped metal nozzle. Such an appli- 
cator makes it possible to shoot the dust into small crevices. The dust 
is effective as long as it is dry. Where nests are inaccessible and 
difficult to find, poisoned-meat bait may be used as an effective means 
of control. If buildings are set upon stone or concrete foundations, 
the timbers will usually be kept so dry that they will not provide 
favorable nesting places. In the forest the ants gain entrance to the 
trees only through injuries. Fire scars, axe marks, and other surface 
injuries should be prevented as far as possible, to avoid the entrance 
of ants and also of wood rots. 
The Texas leaf-cutting ant (Atta texana Buckley) has long been 
known as a defoliator of plants in Texas and Louisiana. Walter, 
Seaton, and Mathewson (424) gave an account of its life history and 
control. These ants have the habit of cutting leaves from a great 
variety of plants and carrying them to their nests. Each leaf is 
finely divided and made into small pellets within the nest. The small 
masses are placed upon a so-called fungus garden, where they supply 
a medium for the growth of a fungus, which furnishes the colony with 
food. As the supply of fungus is consumed the ants add leaf pellets 
to the old mass. Evidently the ants exercise great care in preventing 
the contamination of the fungus garden by any other species of fungus. 
In many cases the attack is concentrated on one tree, which may be 
entirely defoliated in a single night. The nest consists of under- 
ground chambers with many openings or craters. The surplus open- 
ings seem to be provided for the purpose of ventilating the under- 
ground passages. The ants seem to prefer to construct their nests 
in sandy soil, but. nests are by no means restricted to this type. Many 
of them are constructed near the base of a tree, so that roots help sup- 
port the soil over the galleries. 
In 1934 these ants were recognized as serious pests of young pines 
on the Kisatchie National Forest, in Louisiana. Smith * gave an 
account of the control work conducted there. The ants attack young 
planted pine late in the fall and early in the spring, when there is a 
3% SmitH, M. R. THE TEXAS LEAF-CUTTING ANT (ATTA TEXANA BUCKLEY) AND ITS 
CONTROL IN THE KISATCHIE NATIONAL FOREST OF LOUISIANA. So. Forest Expt. Sta., 
Occasional Paper 84,11 pp. [Processed.] 
