90 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 1 



We find insecticides recommended against this insect in the works 

 of Dr. Cyrus Thomas, formerly state entomologist of Illinois, and pub- 

 lished in the transactions of the Illinois State Horticultural Society 

 for 1876. Townsend observed the insect in New Mexico upon peaches 

 and recommended contact sprays against it in Bulletin No. 3, New 

 Mexico Agricultural Experiment Station, June, 1891. Saunders, 

 Weed and many others have also suggested treatments. Washes of 

 strong soap-suds, tobacco-water, kerosene emulsion and many other 

 contact insecticides commonly used against sucking insects were ad- 

 vised. 



From the experience of the writer, it has seemed that time and man- 

 ner of application has had much to do with successful results. I have 

 conducted experimental spraying against this insect near St. Louis, 

 Missouri, in a peach orchard of about one hundred and thirty medium 

 aged trees, the spraying being done oh November 16. In Colorado a 

 commercial peach orchard at Palisade was carefully selected and 

 treated on March 16, 1907, when the stem-mothers were thickly cover- 

 ing the outside of the peach bud. The peach buds were swollen and 

 ready to burst into bloom. The first new-born of the second genera- 

 tion were appearing, but neither these tiny green lice nor the larger 

 pink-bodied stem-mothers had gained entrance into the blossoms be- 

 yond the reach of contact sprays. At that date practically all of the 

 eggs had been hatched. 



An orchard of about one hundred peach trees at Grand Junction 

 was chosen in which no spraying was given up to April 16, when por- 

 tions were given a thorough treatment with different contact sprays. 

 At the time this spraying Avas done, the leaves of the trees were badly 

 infested and the lice concealed to a large extent within the folds. 



In both of the orchards a thorough spraying was given, but it was* 

 plainly apparent that the orchard first mentioned — the one sprayed 

 late in the spring, but immediately preceding the opening of the 

 buds — was the one in which the better results were secured. In the 

 one sprayed after the leaves had become curled, it was found almost 

 impossible to reach the bodies of the lice. Some of course were killed 

 when a strong stream of spray was forced into the branches under a 

 high pressure, but it was manifestly too late to expect the best re- 

 sults. 



Among the most promising insecticides used in the experiments and 

 by orchardists who sprayed last spring for this pest in Colorado were 

 kerosene emulsion, containing 5% oil, Scalecide diluted 1 part to 20 

 parts cold water, tobacco decoction made by steeping for an hour 1 

 pound of leaf tobacco or 2 pounds strong tobacco dust or stems in 



