- 21 - 
Cinara sa'oinae (G-illett* ft Palmer), a red cedar aphid 
IlcDaniel (187) in 193^- reported that this red aphid can "be controlled 
"by derris strays used according to the directions of the maker. 
Eriosoma lanigeru m (Hausm.), the woolly apple aphid 
The derris preparations Contraphin and Katakilla were useless 
against this insect. — Wahl and Muller (29U) in 1915. Gimlette (120) in 
1923 reported work that H. E. Durham did with derris in 1903- Derris 
had no effect as a contact poison on the woolly apple aphid. Tattersfield 
and Roach (2oU) in 1923 also referred to unpublished results of work "by 
Durham, who found the woolly aphid resistant to the wet application of 
derris. Durham (91) in 1926 gave an interesting account of his early work 
with derri?, which started in the Malay States in 1902 and continued in 
Sngla.nd in 190^-. An extensive series of trials on the woolly aphid were 
carried on throughout the summer, "both with spraying and with careful use 
of a camel ' s-hair brush so as to get thorough wetting of the patches, 
which had a milky appearance '-'hen treated. The woolly aphid is difficult 
to wet, but in no case was there any appreciable diminution. Durham ex- 
pressed the opinion that, whether or not there may be a contact effect, 
the :nain utility of the drug must be as a stomach -ooison. 
-Teoton 375 g^- "l^lus 1,125 gm. of soap in Uo imperial gallons of 
water killed 100 percent. — Institute of Physical and Chemical Research 
( 162 ) in 1927. 
DeOng (75) in 1930 used this as a test insect in determining the 
insecticidal value of four species of derris (pondered stems applied as 
dust). The results after 7 :0 days' exposure were as follows: 
Derris species 
Mortality 
Percent 
D. elli-otica 
D. trif oliata 
D. heptaohylla 
D. pol y a.ntha 
Check (no treatment) 
100 
ICO 
55 
Us 
The TT andelsmuseum of the Koloniaal Instituut of Amsterdam (8) in 
1930 reported that derris was an exceptional material for control of 
aphids on flowers and fruits in the greenhouse, but that the woolly aphid 
was protected by its covering. 
Overley and Overholser ( 218 ) in 1932 reported that apple trees in 
Washington that had been sprayed with rotenone were free from woolly 
aphids, whereas on other plots there was a general infestation. Rotenone 
in oil (1:25,000) was highly effective in laboratory tests. — Turner 
( 271 ) in 1932. Derris or rotenone suspensions at a concentration of 
1:5,000 or 1:6,250 were effective. — DeBussy et al. (32) in 1935. 
Rotenone and dihydrorotenone were about eoually toxic to this 
species on apples, when used as a spray containing 0.1 to 0.5 percent 
of Agrai. At 1:5,000 r?teno-.e killed from 80 to 90 percent and at the 
