- 5 - 
immediately planted. Two hundred pounds of tobacco dust, to which 0.25 
percent of rotenone from derris powder had "been added, was used per acre. 
The tobacco-derris plot came up to a good stand. In the third series of 
tests 1.6 -oounds of derris was mixed with 100 pounds of cotton seed just 
"before planting. The seed treated with derris germinated more ouickly 
and was up 2^ hours earlier than the checks. There was very little re- 
duction in the number of aphid colonies. 
Anuraphir. oersica.e-niger (Smith), the black peach aphid 
In the field the mortality of this species when sprayed with a 
suspension of pure rotenone in water, 1:1+0,000, was So.J> percent. 
Davidson (6j0 in 1930. 
Anura.vhi^ roseus Baker, the rosy apple aphid 
The ITew York Agricultural Experiment Station ( 211 ) in 1928 reported 
that rosy aphid infestation of a'ople trees was noticeably reduced by Der- 
risol. Van Surer. ( 307 ) in 1323 reported Derrisol to be effective. Farrott 
got about 8 percent of the rosy aphids on Rome tree<= when Derrisol a.t 
1:200 was used, as compared with a little less than 1 percent on plats 
sprayed with lime-sulfur and nicotine sulfate. In thr field the mortality 
of this insect ^hen sprayed with a suspension of pure rotenone in '-'ater 
was 96.3 percent at a concentration of l:Uo,000 and 90.2 percent at a 
concentration of 1:60,000. —Davidson (63) in 1930. 
Parrott and Glasgow ( 220 ) in 1930 reported trials of different in- 
secticides against the rosy aphid in ?.7ew York. The results with the derris 
preparation, Derrisol, were as follows: 
Insecticide Aphid-attacked apples per tree 
Percent 
Lime- sulphur 1:^0 + Derrisol 1:300 22.17 
Lime- sulphur l:Uo + Derrisol l:l600 
+ nicotine sulphate l:l600 7-39 
Bordeaux U-U-50 + Derrisol 1:800 U3.90 
Check plot • 51.65 
In ~>ast seasons sampled of Derrisol, although consistently inferior 
to nicotine sprays, greatly reduced the aphid population. 
Both rotenone and derris extract proved much more toxic than pyre- 
thrum extract to this species (cf. Aphi s ^cmi Deg.). The tests were ma.de 
dipping apple twigs infested with these aphids in solutions of various 
concentrations. — Oinsburg and Schmitt ( 125 ) in 1932. 
Anuraphis tulipae (Fonsc), the tulip bulb aphid 
Dusting the bulbs with derris is effective in controlling infesta- 
tions of the tulip aphid. --Wilson ( 309 ) in 1938. 
Aphis gcssypii C-lov. , the cotton aphid, or melon aphid 
Mclndoo et al. (139) in 1?19 reported that the alcoholic extract 
