888 Revort OF THE DEPARTMENT OF ENTOMOLOGY OF THD 
Ill. OTHER PROMISING INSECTICIDES. 
The economic importance of scale insects as a group has re- 
sulted in unusual efforts being made to develop methods for 
their control. Ags a result various compounds are being devised 
and tested from time to time with the hope of finding a cheaper 
and more effectual way of combating these insects than any that 
has yet been devised. Among the compounds that give promise 
of success are the following: | | 
Whale oil soap and crude petroleum compound.—Both whale oil 
soap and crude petroleum are known to have great insecticidal 
value and hence it would be supposed that a combination of the 
two would give highly satisfactory results. The experiments 
thus far, however, that have come to the writer’s knowledge, 
have not given altogether satisfactory results. A series of 
experiments by Felt, gave no better results than he had ob- 
tained with a plain 20 per ct. emulsion with water. In these 
experiments, however, the emulsion was not used very strong 
as but one pound of soap was used to each four gallons of water. 
This was emulsified in a “kerowater” pump with a small 
amount of oil, the pump being set to discharge but 10 per ct. of 
crude petroleum. 
This compound is undoubtedly worthy of further experiment. 
It is not improbable that a stronger emulsion would prove more 
effectual. 
Lime, sulphur and salt wash—This compound has been used 
extensively and with much success in California. The prolonged 
periods of dry weather characteristic of that country are espe- 
cially favorable to the use of compounds of this kind. Experi- 
ments with this insecticide in the East have not given very satis- 
factory results as arule. A prominent exception, however, is a 
series of experiments by Marlatt, conducted at Washington, and 
published in Bul. 30, N. 8., U. S. Dept. Agr., Div. of Entomology, 
pp. 34-36, which gave very promising results. In explanation 
of the unusual success of the treatment Dr. Marlatt states 

*Bulletin N, Y. State Museum, No. 46, Vol. 9, p. 337. 
