New York Agricultural Experiment Station. 409 



states that the large growers in that country will not use tarred 

 disks, but the liquid soil insecticides have been used with good 

 results. 



The above discussion deals only with some of the references to 

 carbolic-acid emulsion that occur in the literature of the cabbage 

 maggot. These references show, however, that the material has 

 been regarded by entomologists as a strong larvicide; that it will 

 injure plant growth when not sufficiently diluted, and that it may 

 have some effect as a repellent. The experiments recorded by 

 Washburn suggest that, even when used at a dilution of 0.37 per ct., 

 the carbolic acid may have a retarding effect upon the growth of 

 the cabbage. 



Laboratory tests to determine the effects of carbolic-acid emulsion 

 on the eggs of the cabbage maggot: Test No. 1. — Three lots of 

 eggs were placed in clay saucers and immersed for five minutes in 

 carbolic-acid emulsion containing 1| per ct., 0.66 per ct. and 0.33 

 per ct. crude acid, while other eggs were left untreated as a check. 

 Apparently the carbolic acid had no effect on the time of hatching 

 or the percentage of eggs hatched. 



Test No. 2. — In this experiment eggs were placed between moist 

 filter papers which were then slightly covered with sandy soil, similar 

 to that occurring in fields in which early cabbage is grown. The 

 liquid insecticide was then applied to the soil as if the eggs were 

 about cabbage plants. The results were as follows: 



1 .33 per ct. acid 15 eggs hatched. 



.66 per ct. acid 15 eggs 5 hatched. 10 not hatched. 



.33 per ct. acid 15 eggs hatched. 



Check 15 eggs 15 hatched. 



Test No 3. — This is a repetition of Test No. 2. The results are as 

 follows : 



Results. — Attention is called to the results of tests Nos. 2 and 3 

 in which eggs remained in contact with the soil that had been wet 

 with the liquid insecticide, until the surplus liquid evaporated, as 

 would occur when plants are treated in the field. In these tests 

 the carbolic acid functioned as an ovicide, and mixtures as weak 



