-73- 
Tests in Wisconsin indicated that dust mixtures containing 0,1 
to 0.25 percent of rotenone, and 2 percent of Lethane 60 or 1 to 2 
percent of Loro were comparable with dust mixtures containing 0.75 
percent of rotenone and 1 percent of SAE 10 lubricating oil. Oil 
added to rotenone dusts, when stored for some time, may cause a re- 
duction in toxicity, but such dusts can be reconditioned with the 
addition of 1 percent of oil. A summary of greenhouse tests with 
rotenone dusts showed that the aphid control was significantly im- 
proved by increasing the oil content of the dust mixture from 2 per- 
cent to 4 percent.— Wilson and Campau (686 , 687 ) . 
A rotenone-nicotine blend recommended for the pea aphid con- 
tains: Rotenone 0.375 percent, nicotine alkaloid 1.7 percent, sul- 
fur 10 percent, hygroscopic agent 1 to 2 percent, and the remainder 
pyrophyllite or a satisfactory talc. Both field and laboratory 
trials showed that 0.5 percent of rotenone will gi"ve almost as good 
control as the 0.75-percent product which formerly was the standard, 
when both are used with oil and a suitable diluent.— Wisconsin 
Agricultural Experiment Station (697 , p. 47). 
Macrosiphum solanifolii (Ashm.), the potato aphid 
Rotenone is more effective than nicotine against this aphid on 
potatoes. It was recommended in February 1942 that a 0.75-percent 
rotenone dust be substituted for the 1-percent rotenone dust former- 
ly used.— U. S. Bureau of Entomology and Plant Quarantine (626 ) . 
The general use of pyrethrum-sulfur or rotenone-sulfur com- 
binations on potatoes may be limited by their failure to prevent late 
blight and by their higher costs.— Daines and coworkers (134 ) . 
Cube dusts (0.75 percent of rotenone) were effective, but py- 
rethrum dust gave erratic results and were definitely less efficient. 
The use of pyrethrum and rotenone dusts instead of bordeaux mixture 
for control of potato insect pests has been recommended because 
bordeaux, in many years, has decreased yields.— Rawlins and ooworkers 
(493). 
Myzus persicae (Sule.), the green peach aphid, spinach aphid, or to- 
bacco aphid" 
Calcium arsenate undiluted was used alone and in combination 
with derris (0.5 percent of rotenone in mixture) • The derris had 
some effect in retarding aphid increase on peppers in California, but 
not enough to prevent serious aphid infestations.— Blmore and Campbell 
(163). 
