- 112 - 
Derris with the sticker has givon promising results. The derrig spr?iy has a- 
dis?.dv?jitagc in that it is neccssarv to repeat the aT^plication every week to 
maintain good control. 
The United States Department of Ai-riculture, Bureau of Entomology and 
Plant Quarantine, Japanes Beetle Latoratory ( 3 ^1 ) ^ found that samples ff 
Tephrosia F. virginianal were not effective as stomach poisons or repellents for 
vie JaDaneae "beetle. Bydrated lime was mixed with derrig as a spray without 
destroying the repellent vplue of the material. Exposure of rotenone to sun- 
light for 2 days definitely decreased the effectiveness as a repellent and 
stom^ich prison. Several different feils, waxes ^ resins, asphalt, latex, agar- 
ag^r, flour, and other materials ^rere tested to determioe the effectiveneBs 
©f thp«!e materials as s-tickers for derris. It vras found that rosin residue, 
thF residual material left in the stil' during the manufacture of rosin, when 
emulsified vrith ammonium caseinate, vras a satisfactory and , inexpensive sticker 
for derris, as tested in the exp<"riment?il orchards. More recent experiments 
indicated that replacing the ammonium cas'inatc with gum arabic produced a 
"b'-tt'-r sticker for derris, 
A large num'b''^r of materials have y}r>s-n fidded to derris in various ways 
to overcome the decomposition of the mr'torial in sunlight. Some mixtures were 
ma.do hy adding derris to emulsions or disprrsions of the material in watf^y; 
other mixtures were made by cooting the derris with the material. In tjie lattei- 
case the coating material vras dissolved in a suitable solvent, the finely di- 
vided derrig added, and then the solvent removed by evaporation. It appears 
that, in gen- ral, better protection is obtained by th' latter r:rocedure. Among 
the materials which have been added to derris in different vrays are lamp black, 
white, black, and green pyroxylin, different grades ^f wood rosin, rosin resid- 
ues of different types, apphalt, coal tar, pine tar, pine pitch, paraffin, bees- 
wax, spermaceti, cariiauba wax, gilsonite, sulfur, lime-sulfur, bejttonit<^, tit- 
anium oxide, magnesium silicate, calcium tS^rbonate, aluminiim sulfate, montan 
vrajc, pine oil, blov/n sardine oil, blovrn castor oil, glue and formaldehyde, bone 
glue, boiled linseed oil, halowex, apple wax, ravr menhaden oil, and casein, Thr . 
oils, in genrral, were found to be good stickers for derris, but accelerated the 
decomposition of the derris, Me.gncr-ium silicate g^^vc indications under labora- 
tory te«it of retarding the decomposition, but und-' r field conditions it appearec 
to have no effect on the decomT)osition, Laboratory te<?ts indicate that rosin if 
a good protective '^^grnt for dorris. • Wh^n derris was coated with rosin, th*^ de- 
composition wes greatly retarded. Physical mixtures of derris and rosin wore 
not "^a.tisfactory. 
A study was made of the rein ti on betvrepn temperatur'' and light fln the 
decomposition of derris, Derris deposits, in the absence of light, were n»t 
appreciably decomposed rt temperatures ranging frtm 37^ to JO^ F. • Derris ex-^ 
posed to direct sunlight in the winter with low temperatures decomposed less 
rapdily th^n vrhen exposed to sunlight in a grf^enhouse at a temperature ©f 7^^ P, 
The results indicntc that temperature a,nd light are important fact«rs lnfluen#^-| 
ing the decomposition of derris. 
Thren applic-Ttlons of derris and rosin-residue emulsion gave almfst eom- 
plrte protection to early ripening -oefiches, whil*^ no fruit was har-"'ested fr«m 
unrjpr^yed trees. The effectiveness of the derris as a repellent spray disappear 
<"d in 9 to 12 days, even in the absence of rain, making it necessary -to report 
the qripiicationB at about weokly intervals. The addition of magnesium sllic'ate 
to the derris spray appeared to havp no effect in retarding thr oxidation ♦f 
derris. As this spray leaves no ob,iectionable rf^sidue on the fruit, thf^' trees 
cnn b-^ pprayf>d ur to a fevr day. befor'^ hprv-^st. Derris nnd rotenone were found' 
