- 79 - 
It was suspected that this protr-ction was due to the adsorption-a'bsor-ntion 
and translocation of. tho derris or culie constituents. ¥ith this in nind, 
tests were xmdertaken to determine vh:~ther this phenomenon could "bo explained. 
Feeding test? were r.ade with the larvae. Chloroform extracts of leaves wore 
also tested on goldfish. The authors concluded that a definite retarding 
in the feeding of Mexican bean "beptle larvae has "been observed on the new 
grov;th of bean plants treated with derris pov/der. First, second, and third 
trifoliate leaves, formed after the first pair of true leaves had been 
tre^-ted, were fouj-.d to be less palatablf to bean beetle larvae than similar 
leaves from untreated plants. Extracts prepared from first, second, and 
third trifoliate leaves formed after the application of derris powder to 
the first pair of true leaves caused 100-percsnt mortality to goldfish. 
Extracts prepared from first, second, and third trifoliate leaves from, un- 
treated plants were not toxic. A water extract prepared by macerating now 
growth of bean plants that had been treated with derris was fatal to gold- 
fish. In -one instance, where a large eua.ntity of new-grovrth material was 
available, a crystalline substance resembling rotenone was isola.ted. The 
material when purified had a melting point of 163.5° C. , gave the charact'^r- 
istic color with the Gross-Sm.ith method, and the blue color test of Durham. 
One mg. of this substance in 65O cc. of water at 26.7° C. killed three 
goldfish in an average of 77 minutes. These experiments demonstrate th^t 
derris constituents are translocated from the outer surfaces of leaves to 
first, second, and third trifoliate leavf^q for.med after the application of 
derris powder in water suspension to the first true leaves and stems of 
bean plant <; . 
Huckett (206) in iq^S reported tests of cube mixed with each of the 
following: Sulfur, sulf-or and celite, bordeaux m.ixture, and celite and 
clay for the control of the Mexicrn bean beetle. Two samples of cube 
powder were compared, one analyzing 2 percent of rotenone 8.nd Ig percent 
of total eth^^r extractives and the other 5 percent of rotenone and 12 to 
lU percent of total ether extracti-'-es. These powders were applied in 
sulfur spray and dust mixture? at strengths eouivalent to U pounds of cube 
powder to 100 gallons of we tta,ble- sulfur spray and 10 pounds of cube pov^der 
in 100 pounds of a cube plu? celite plus ground- sulfvir-dust mi-' turo. 
Huckett concludes that according to larval population counts and yield of 
pods, mixtures c^ntainin^;; cube powder of 2 percent of rotenone and 18 per- 
cent of total eth.r extractives were as effective at the dosage-? used as 
those containing cube ponder of 5 ^^ercent of rotenone and 12 to lU percent 
of total ether extractives. In field tests on lima beans sprayed and dusted 
v;ith cop-per-lime mixtures for control of plant diseases it was observed that 
bordeeux mixture, as applied, possessed considemcle merit in thpt it had 
notably reduced the amount of feeding by Epilachna v^rivestis . This effec^, 
it v;a? observed, was slightly c-nhajiced by the addition of cube powder to the 
fixture at the time of application or by making separate applicrtions of 
cube-clay dusts following treatm.ent with bordeaux mixture. 
The Indiana Division of Agriculture (212^) in IP^S published information 
on the control of the Mexican bean beetle. Derris or cube powder, contein- 
ing U percent of rotenone, should be used in the proportt6nn of 3 pounds of 
pov/der to IOC gallons of water. F.otrnone dusts are inferior to rotenone 
s J) rays. 
