- 10 - 
assumed to contain approximately l/2 pound of powdered dcrris root and 
6 pounds of soap per gallon. This dorris-soap mixture was used at the 
rate of 10 pounds to 100 gallons of water. Applied at the rate of 13-1/3 
gallons per tree, the derris-soap mixture killed 99.2 percent of the 
insects. This same mixture, in three different tests, injured 6, 6.3, 
and 14.1 percent of the apples, the average being 13.2 percent. Derris 
and tobacco dust, applied erthcr in dry state or with lime-sulfur, dis- 
played high toxicity against redbugs, Kopp (_5£) in 1924, in a review of 
the insecticidal uses of dcrris, referred to the above report. 
The New York County Agents' Training School (67) held at Ithaca 
on December 19, 1938, heard reports on rctenone products as follows: 
A spray of 3 pounds of cube plus wcttablc sulfur gave a control of 73.7 
percent of the bright apple redbug on Mcintosh apples. Nicotine sulfate 
at 1:800 plus lime-sulfur gave the best control, namely, 93.9 percent. 
Ly gu.s api cal is Fieb. 
Smith, Clark, and Scales (80) at Tallulah, La,, in 1934 compared 
the ef feet iven ess of derris, cube, and other insecticides against L, 
apicali" in cages and in the field. Both derris and cube contained 4 
percenx r.f rotenone. The insecticides were applied as dusts, according 
to the i ■"■-.! t "ocedure for field dusting, with a small hand dust gun. 
The results were as folio 1 / s: 
Treatment : Mor tali ty of 
: Adult'-; M;~:, ; ~ 3 
Percent Percent 
Cube only 41.5 44.8 
Derris only ----- 51.8 41,1 
Derris + sulfur(l+7)- 68.6 71.6 
Calcium arsenate- - - 33,3 58,6 
Check 18.8 15.7 
As shown in the table, cube was not equal to derris of equal 
rctenone content. The highest kill of both adults and nymphs was ob- 
tained with the derris-sulfur dust of highest sulfur content. 
Lygus campestris (L.) 
A ground mixture of 2.5 parts of Derris elliptica root, 7,5 parts 
of sab l.la ■ ieds, and 90 parts of talcum proved useful in exterminating 
these b ;, Instead of the drugs, their effective extracts or the al- 
kali .-covered therefrom may be used; for instance, by mixing 0,2 
pen i roi none, 0.3 percent of veratrin, and 99,5 percent of kaolin. — 
Scfc ' i. and CoYnitz (76) in 1935. 
Lygus h ■ = rus Knight 
In 1936 Cassidy and Barber, in a quarterly report to the Division 
of Cotton Insect Investigations of the Bureau, stated that in plat tests 
cube was less effective (45.2-pe rcent control) than derris '( 52. 8-percent 
control) against L. hesperus. 
