- 79 - 
Foliafume (a pyrethrum-derris spray rath spreader) at 1:400 killed 
85 percent in 48 hours,,— -Penick and Conp'any (25jf, in 1936. 
Devris or rotenone suspensions vrere Ineffective,— DeBussy et al. 
(J52) in 1935, (31) in 1936, 
Not affected by derris, — Van der Laan (17?) in 1951; DeBussy et al. 
(31) 
Pul Tr inaria vitis (L. ), the cottony maple scale 
Hamilton (153) in 1938 reported cube and derris poivders (4 percent 
rotenone and IS to 13 percent total extractives) applied as a spray at 
rate of 4 pounds per 100 gallons vith the addition of 4 pounds of rcsin- 
residue er.ulsicn to be a fair contact poison against this insect on maple 
tree.:. nicotine is totter. 
Saissctia h emispha erica (Targ. ), the herd spherical scale 
Rotenone in oil vas highly effective. — Turner ( 271 ) in 1932. 
Saissetia oleac (Eern,), the black scale 
The Bureau of Post -Control of the California Fruit Growers' 
Exchange, in the November 1935 issue of their Post Control Circular (54) 
reported results of tests v/ith nex; citrus sprays against uniformly sseall 
black scales, as follovra: 
Average 
Material and dosage Amoun t of oil added mortality 
Percent 
Ortho Derris, 4-5 lb. 0.5 pet, light-medium to 
per 100 gal. 0.S7 pet. medium 99,06 
Regular oil spray 1,67 pet. soluble or 2 
pet. emulsion • 99.7 
Ortho Derris, sold by the California Spray Chemical Company, uus 
the nest - 1; used spray of the nonoil materials during the regular black 
scale s . A considerable number of groves i.-ere treated -huh satis- 
factory results; although, as shov.u in the last column of the table, it u-as 
someurhat less effective than the regular oil sprays, ho date no injury by 
this sg-- ' has been observed en either or ripe fruit, or or foliage, 
Tox-X (2 b .: percent rotenone) at 1 pound per 100 gal n u s >lus 0,5 to 0.37 
percent light-medium or medium oil killed £9,1 percent of small black 
scale. Against black scale Tox-h vjas equal tc Ortho Derris but not guite 
so effective as regular oil sprays. 
In ist 1936 issue sf Pest Ocntfol Circular (35) re r lug 
so-called nonoil sprays, it is stated that Crtho Derris -' are 
composed of a poudered insecticide coni ; derrii - ' ' losage 
of light medium oil, usually 0.5 to 0.67 perc . Largel; 
