208 



JOURNAL OF ECONOMIC ENTOMOLOGY 



[Vol. 14 



terminal growth of many of the trees was damaged. In Plat I ten 

 Greening trees were dusted with a preparation containing 0.5 percent. 

 nicotine. A little more than fifty pounds of dust were applied and one 

 tree (Tree 1) was ver>' thoroughly dusted. In Plat II seventeen Green- 

 ing trees were dusted, using from eighty-five to ninety pounds of material. 

 One Greening tree (Tree 2) was given an application of two and one-half 

 gallons of lime-sulfur diluted with one hundred gallons of water to which 

 was added one pint of nicotine sulfate. To insure thorough treatment, 

 twenty-three gallons of the mixture were applied. In the treatment 

 of the individual trees much care was exercised to make thorough 

 applications without any attempt to economize on materials. Fumiga- 

 tion sheets were spread on the ground beneath each tree in order that 

 the redbugs could be collected as they fell. After the first count the 

 trees were shaken quite violently at repeated intervals and after each 

 operation the condition of the insects, whether dead or alive, recorded. 

 The effectiveness of the different treatments is indicated in Tables I and 

 II. 



Table I — Effects of Dusting on Redbugs 



Condition of Insects 



Tree 1 

 Dusted 



Tree 2 



L. S. ard 



Nicotine Sulfate 



Tree 4 

 Check 



Dead . . 



Living . 



Total 



437 

 132 

 569 



594 



36 



630 



Percent. li\ing. 



14 

 317 

 .331 



96.7 



Redbugs proved very sensitive to nicotine, dusting preparations 

 carrying this ingredient producing almost instant paralysis upon coming 

 in contact with the insects. No difference in rapidity of action or in 

 effectiveness was discerned between the dusting preparations which 

 contained respectively 0.5 and 1.0 percent, nicotine. 



The Apple Aphids 

 The conditions under which the experiments with aphids were carried 

 •out may be briefly described as follows : Apple buds infested with newly 

 hatched n^inphs of avence, pcmi and sorbi, principally the former species, 



