EXPEKLMEXT STATION. [Jan. 



TESTS OF INSECTICIDES. 



n. T. FERNALD. 



It has not been the policy of the department of entomology 

 of this station to condnet tests of the different insecticides on 

 the market, the department having no trees under its control 

 upon which tD make the tests. In a few cases, hojvever, special 

 reasons have led to a departure from this rule, and the results 

 of a few trials of such materials are given here. !N^o attempt 

 is made to draw final conclusions in any case, those given being 

 only such as the tests themselves indicated. It is recognized 

 that farther trials of these materials in other localities, or per- 

 haps under different climatic conditions, might give different 

 results, but as such are not available only those actually ob- 

 tained here are recorded. 



Entomoid. — Manufactured by Frank M. Hale, Woonsocket, 

 R. I. This material was tested in 1911, and the results are 

 given in the last annual report. Entomoid is claimed to be a 

 combination of lime-sulfur and a miscible oil, and should pos- 

 sess the good qualities of both of these materials. The manu- 

 facturer believed that a modification of the formula used in 

 1011 would be an improvement, and it was this modification 

 wliich was used in 1912. Several apple, pear and plum trees 

 and currant l)nshes considerably infested with San Jose scale 

 were sprayed with it, following directions supplied by the 

 manufacturer to dilute 1 part of the Entomoid with 50 parts 

 of water. On two trees a dilution with 40 parts of water was 

 used instead, in order to determine any possible injury by a 

 stronger solution or possibly a greater effectiveness. The treat- 

 ment was applied April 17, the day being calm, cloudy and 

 with a temperature of 05° to 70° during the treatment. The 

 material mixed easily with water and sjU'ayed well and was 

 dry within a short time. There was quite a heavy rain that 

 night and also some the next day. 



