- Us - 
Turnpr (376 ) in 1932 rr^ort^cl that in,la,"*:":'rptor7 tests r'^ten-^n? 
in miner?! oil 1:25,000 killed Jo r.-rcpnt of '-Colovpc.o T'Ot?t~ n.-^etle larvae 
in 6 days. Lerd arsenate at I-I/2 pounds t^' 100 gallons killed l"''^ ■'-ercpnt, 
and 23 percent died on the ■untreated check. In these tests tho larv^ie 
were transferred to cut potato shoot=i after the spray ha:'', dried. 
At the 193^ neetine of th^? A-ierican Apsociati-^n of Sc^nonic Snto'^o- 
logists, Cory ( 3SS ) led a discussion on field results with arsenical sub- 
stitutes f-^r the control of ve.^'-^tahle ins'-cts. According t'^ Hea'Uoe of 
New Jercey ( IS3 ) in 1935, the ' Colorado potato "beetle can "be controlled "by 
derris dust. 
Lapr,arent ( 257 ) in IQ^U reported that in Franco trials vdth eu"':!e 
a.nd derris pc^^rders ( 5 percent of rotenone) against the Colorado notato "opptl 
gave good results. 
The Alaba-na Polytechnic Institute (g}_ in IQ35 stated that derris 
dust (0,5 percent of roten-^ne) is effecti-"'e in controllinf-: Tot.ato "beetles 
when applied ?^t the rate of 10 pounds per aero, 
Feytaud ( 12S ) in 1^35 referred to the use of rotenone powders for 
con"bating the Colorado potato "beetl- in France. The. type foraula is 5 
parts of powdered derris ^r cu"be (rotenone not less thpn. 5 T'erc^nt) and Q5 
parts of talc or kaolin, 
Feytaud and Lapparent ( I30 ) in 1935 reported favora"ble results 
against the Colorado potato "beetle in France with a terpinolene extract of 
derris (or cu"be) emulsified in vrater. T].iese workers v^repared terDinoleno 
extracts of derris and cube "by macerating S s^m, of root with 100 gm. of 
terpinolene for 3 *^ 5 days. After "b'^in^ filtered and emulsified, this 
extract killed larvae of the Colorado potato "beetle at a dilution ^f 1:19 
with wnter. 
A good emul«:i'->n is made "by mixing 700 gm. of the t.-=rpinolene 
extract with 30*^ c-Tn. of sulfated highor fatt" alcohol (oleyl, lauryl, 
cetyl). This is "better than sodi\Lm resinate. Terpinolen--" , or essence 
of pine^ is rich in iso-cineol. 
Later, Feytaud and Lp-:^-^arent (I3I) reported that in la"boratory 
tests against the Colorac'.o potato "beetle it was necessary to use the 
following: quantities of a product containing about 16 percent of the 
extractives of derris, of which 5 percent was rotenone: lOQ gm. p"r 
hectoliter of water for younr larvae, 20^""- gm, per hectoliter of vrater 
for old larvae, 50*^' gm. per hectoliter of wpter for adults. Derris ex- 
tract in terpinolene is made as follovis: 15 gm. of powdered derris or 
cube (rotenone = 5 percent) is macerated for 5 days at a tem'-ierature 
not above 30'^'C. in 100 gm. of terpinolene, then filtered and ke^t in 
a tinted glass flask to escape the action of light. A mixture is made 
of derris extract in terpinolene, 60 parts: terpineol, 20 parts; sulfated 
olnyl alcohol, 20 parts. Preferably the last two ingredients are mixed 
first and the derris extract then added. For use t^iis mixture is added to 
water to make a 0.5^percent emulsion. Ammonium <?ulforici^ate may also be 
used as a.n emulsifier. A 0.5-p-rcent emulsion of this applied to fourth 
instart of the potato beetle killed 30 percent in 2U hours, 75 percent in 
Us hours, and 100 percent in U days. 
