December, '08] JOURNAL OF economic entomology 349 



exit of each burrow and filled with the poison. The whole ground 

 was gone over in this manner. An examination was made the next 

 day and resulted in finding less than twenty-five live ants on all the 

 ground treated. In and around some of the pits were heaps of dead 

 ants which apparently had been carried out by such members of the 

 colony as escaped destruction. A second treatment of these colonies 

 usually reached what still remained alive. Where no dead ants had 

 been brought out, probably the entire colony was destroyed. One 

 of these burrows was opened up with the result of finding pockets 

 filled with dead ants as much as one and one half feet below the sur- 

 face. A few days after using this insecticide the pits were refilled 

 and the ground leveled. Ten days later an examination showed about 

 a dozen fresh burrows of apparently very weak colonies. A second 

 yard was treated after the same manner with almost complete eradi- 

 cation. 



Our success with this cyanide solution in almost freeing ground of 

 ants by the use of one, or a partial second, application leads us to 

 believe that under favorable conditions ants (at least some species) 

 can be entirely eradicated from a piece of ground by repeated appli- 

 cations. The poisonous gas from this solution must penetrate deep 

 into the ground. A strong odor of the gas was evident in a burrow 

 opened up two days after the solution was applied. It is entirely 

 possible that this solution will prove of some value against the ground 

 colonies of the Argentine ant. 



The success obtained against the ground form of ants suggested that 

 the insecticide might be put to some use against various ground forms 

 of insects as woolly-aphis, thrips, etc. To determine this point it was 

 first necessary to learn if the solution was injurious to plant life. 

 Two gallons were poured around the base of a large orange tree; 

 Jerusalem cherry bushes and nursery trees of the orange and peach 

 were treated with from one to two quarts of the solution. The orange 

 tree was severely injured, some of the nursery stock was killed while 

 the Jerusalem cherry bushes were injured more or less. This result 

 would appear to demonstrate that the solution is injurious to plant 

 life, which fact would place a limit upon its usage. The cost of the 

 solution is from Ij^a to 2 cents per gallon. 



The use of potassium in powdered form for the destruction of ants 

 was recommended in 1904 by Prof. H. A. Gossard in Bulletin 76, 

 Florida Agricultural Experiment Station, pages 215-16. The trial 

 of this substance against white ants is suggested in 1905 by the same 



