INSECT ENEMIES OF EASTERN FORESTS 627 
Jesion appears superficially like a fungus canker. He believes the 
trees are killed to prevent shade from falling on the mound, and this 
often seems to be the case. Andrews (2) and others, however, believe 
that the ants use less discrimination, often killing trees that do not 
and probably wouid not shade the nest. 
To destroy these ants in plantations, MacAloney and Hosley (287) 
recommend either carbon disulfide or ethylene dichloride as a fumi- 
gant. A dosage of 1 pound (approximately 1 pint) is sufficient for a 
small mound less than 18 inches in diameter. For a medium-sized 
mound less than 21% feet in diameter 2 pounds should be used, and a 
larger mound may need 2 or more applications of 2 pounds each. 
Fumigation should be done late in the fall, after seasonal activity has 
ceased, or early in the spring. Several inches of the top material 
should be removed from the mound and a deep hole should be punched 
in the center and several holes on the periphery. The lquid should 
then be poured in the holes, and the top material should be replaced 
and tamped down firmly. (See Caution, p. 23.) 
The Argentine ant (/77domyrmex humilis (Mayr) ) became estab- 
lished in this country in Louisiana sometime prior to 1891 and has 
spread over a large part of the Southern States, as well as over a con- 
siderable area in California. It has proved to be probably the most 
annoying of the economic ants and a pest of considerable importance. 
Although especially obnoxious to housekeepers, it also causes serious 
losses to orchardists, planters, beekeepers, and others. Out of doors 
the ants feed on the honeydew produced by scale insects, mealybugs, 
and aphids, and do direct damage to vegetation by fostering these 
insects. ‘They also steal seeds from seedbeds and feed on the sap or 
fruit juices from certain trees and plants, particularly citrus. — 
It is possible to eradicate Argentine ants by timely and thorough 
campaigns repeated for several consecutive years. The infested area 
is first delimited by careful survey, and the fact that the Argentine 
ant destroys all native ants within the infested area is helpful in this 
part of the campaign. Poisoned sirup containing sodium arsenite, 
now known as “Standard Government-formula Argentine ant poison,” 
is put out in paperoid cups 20 to 25 feet apart throughout the area. 
(See Caution, p. 23.) The best time to conduct a campaign is in the 
fall or winter since little honeydew is produced at this time of year, 
and the ants will eat the poisoned sirup greedily. Considerable lit- 
erature is available regarding this species. Its life history was pub- 
lished by Newell and Barber (320), and suggestions for control and 
eradication were given by Smith (585). 
 Superrammry VESPOIDEA 
The superfamily Vespoidea includes the true social and solitary 
wasps, as well as a number of families showing great diversity of habit. 
Some are true parasites, some are inquilines, while the true wasps are 
essentially predaceous and insectivorous. The pronotum extends back 
to the tegulae, trochanters are almost always single-jointed, and the 
petiole of the abdomen is without a scale or node. 
As a whole, the Vespoidea are relatively unimportant from the 
standpoint of economic damage done to the forests, so only the larger 
families will be discussed very briefly. 
