- 26 - 
Tests were in8.de v;ith nicotine-lime dust, nicotine s-ilj'hate, calcivun 
cyanide, and derris, ?ive percent extract of derris, 1 to oCO and 1 to 
600, plus soap, ? pcijjtids of £0 gallons, .^sjva satisfactory control, "but was 
slov/ in its effective work. ' The fernery \^ras free fron leafhoppers for 
13 days after the spraying with derris. The roinf ostation occurred from 
eggs dopositod licforc the application of the spray, A second application 
of ...icotinc sulphate ^^-avo 75 to 80 percent control, whereas 5 percent ox- 
tract of derris gave 9R to 99 percent, A snail amount of injury v/as c"bscrvc( 
on all the sprayed plots. It was thoug"ht to "be a mechanical injury cjid not 
considered of any comrnorcial importance. 
Miles (70) in 1925 reported £ood control of the pea inoth Laspoyrosia 
nigricana Stoph. v;ith the use of a derris spray, 20 pou-nds of pov/dercd 
derris to 100 imperial gallons of v.'ator. This spray produced the lov/cst 
percentage of dar.age (15 percent) in the thrcsned peas. The percentages of 
danaged peas harvested from plots tsprayed with derris or nicotine nhow little 
difference from those observed when the green peas were cxariiined; it vrould 
seen, therefore, V.vxt these sprays have a permanent effect. 
ITozu and Son.:yn.r.a (72) in 1926 rccomnended sproying v;ith dorris 
mixtures for the control of the chiysomelid Phaedon incort-gn Baly. 
The Deli Froef station at Medon (22) in 1926 reported that alcar-toe'ba 
extract gave excellent control of aphids. Some difficulty v;as experienced 
in obtaining a uniform extract, so this was prepared with the machinery of 
the Delische Kleiindustrie. Formalin was added, to a concentration of 2.5 
percent, as a preservative. 
Tattersf ield, ^-imingham, and Morris (92) in 1926 reported tests of 
Derris elliptica and rotenone against Aphis nunicis L. Tuhatcxin (rotenone) 
at a concentration of 2.5 to 0.075 grria per liter killed all aphids ♦ 0.01 
gran per liter caused 20 percent to be moribund. Tubo.toxin proved to be 
several times more toxic than nicotine. 
1927 
Quaintance (77), chairman of the comr;iittoe of the American Associa- 
tion of Economic Entomologists to forLiulate plans for invest igr^t ions of the 
codling moth from biologic and control standpoints, reported at the 1927 
annual meeting of this association that, according to Van Lccu\;en, derris in 
laboratory and field tests in 'Jq\j Jersey had shown piromisc for the control 
of the codling i.ioth. 
An anonymous v/riter iZ) in I'einbau and Eellorvjirtschr^ft in 1927 re- 
ported the results of experiments witli Derr is elliptica in ICoroa. A 
thorough application of a coranerclal product [probsbly Heoton — H. C. H.] 
"by rean.s of a sprayer gave good results in the control of the mites re- 
sponsible for the curly-leaf disease. Hepetition was necessary because of 
uneven budding of the vines. The rapidity of the action varies v;ith dif- 
ferent insects. A swarm of almost growi T inea moths on an oai: v;cre ]:illed 
in 1/2 to 1 hour. Black lice on chestnut trees foil off in a fcv/ minutes. 
Rosebush aphids v;erc also- quickly killed. Cabbage worms lived 1/4 to l/2 
hour. Cabbage butterflies flow a\;ay. A largo hornet in flight vras stunned, 
