April, ’24] 
SULLIVAN: CALCIUM CYANIDE FOR FLEAS 
231 
give practically 100% kill in closed buildings. Eight ounces to 100 sq. ft., in open 
buildings will give the same results. 
Calcium cyanide dust was successfully used for controlling blister beetles ( Epi- 
cauta vittata Fab.), in gardens. 
Used at the rate of one ounce to 1500 cu. ft., of space, calcium cyanide dust gave a 
95% kill of white fly (Aleurodes vaporariorum Westw.) in greenhouses without any 
injury ,to plants. 
Calcium cyanide dust gave fair results when used at the rate of one ounce to 25 
cu. ft., one ounce to 50 cu. ft., and one ounce to 100 cu. ft., for periods varying from 
45 minutes to one hour, for the control of San Jose scale (Aspidiotus perniciosus 
Comst.) on mirser}^ stock, apple and peach. 
During the past year calcium cyanide has been used at the Missouri 
Agricultural Experiment Station for the control of a number of different 
insect pests. Due to the fact that Calcium cyanide is a new product 
most of the work with it up to the present time has been purely experi¬ 
mental. However, in a number of cases it has been used with very 
great success in a practical way and on a large scale. The results which 
have so far been obtained lead us to believe that calcium cyanide has 
many possibilities and that in the future it can be safely and successfully 
used for the control of not only certain insect pests but also certain 
other types of animals such as rodents which destroy annually large 
quantities of agricultural products. It must be remembered, however, 
that its use as a remedy for controlling insects is still largely in the 
experimental stage. In most cases methods of application must be 
worked out and the dosage necessary to kill particular insects determined. 
In other words, from the standpoint of an entomologist there are many 
things which we do not know about calcium cyanide. Therefore, in 
this paper I shall attempt only to point out some of the possibilities of 
calcium cyanide when used for the control of fleas and other insects 
and give a brief resume of the results which have been obtained during 
only one seasons work. Additional work may, and I believe will, 
substantiate the results which have been obtained, but on the other 
hand further experiments should be carried out before definite con¬ 
clusions are drawn. 
Calcium cyanide being a material which gives off hydrocyanic acid 
gas, one naturally infers that it can be used for fumigating purposes. 
It may be obtained in three different forms—flakes, granules and dust. 
On coming in contact with moisture either from, the air or the soil the 
hydrocyanic acid gas is given off. All of the different forms are easy 
to handle and where it can be successfully used the process of fumigating 
is greatly simplified. In some instances it is more desirable to use the 
