4 TWO DESTEUCTIVE ANTS. 



which this conclusion is based. He used 98 per cent potassium 

 cyanid at the rate of 1 ounce to 1 quart of water. After careful 

 mixing this liquid was poured into each of the openings in several 

 nests, a quart tO' each opening. In every case it was found that the 

 destruction of the colony followed after one or two applications. 

 The cost of this method is small, but of course will assume consider- 

 able proportions in areas where the ants are very numerous. Even 

 under such conditions it will undoubtedly well pay for the expense 

 and is advised above all methods that can be followed. 



The use of carbon bisulphid is not practical on account of the very 

 extensive excavations the ants make in the sand. Some may be killed, 

 but effective Avork can not be done unless the insecticide is forced into 

 the earth by pressure, and this requires special apparatus. Moreover, 

 the expense would be much greater than in the case of the cyanid 

 method just described. 



Some years ago certain persons in southern Texas followed the 

 destruction of this ant as a regular business. They used sulphur and 

 a special apparatus for forcing the fumes into the nests. The ma- 

 chine consisted of an oven in which the sulphur was burned. The 

 fumes were passed through a pipe by forced draft, and the end of 

 this pipe was inserted into the ground in the middle of the colony. 

 Before the oven was started all of the openings of the nest were care- 

 fully closed. It is said that remarkable success accompanied this 

 method. It may be found to be advisable to use this method for 

 large areas of the infested lands or where several planters can 

 cooperate. 



Mr. C. L. Marlatt has described a method of destruction of ants 

 which is in use in Cuba : 



It consists in digging a bole C feet deep by 3 or 4 feet wide in tbe midst of 

 tbe colony. Tbis bole is filled witb dry brnsb and a roaring fire started. Into 

 tbis is tlien poured a bucketful of powdered sulpbur. Tbe opening is closefl 

 witb a large iron plate. Tbrougb a bole in tbe center of tbis plate air is 

 forcefl down into tbe burning mass witb a large bellows.^ 



THE AGRICULTURAL OR HILLOCK ANT. 



{Pofioiiomiiymcj: hitrhatiis ntolcfacictis Buckley.) 



The nests of the agricultural or hillock ant [Poc/onomyr'Tnex har- 

 hatus molefaciens Buckley) are conspicuous in the territory in which 

 they occur on account of the fact that the ants do not allow any 

 vegetation to grow in a circular area about them. The mounds are 

 15 inches or more in diameter and are frequently covered with parti- 

 cles of earth or sand from beneath the surface which contrast strongly 

 Avith the surrounding soil. The bare areas around the mound may 

 be 10 feet or more in diameter. 



1 See W. M. Wheeler: Ants, their structure, etc., i). 577, 1910. 



