Kopp ( 2^g ) in 192Uj in a reviev; -^f the use '^f Aerris as an insecti- 
ci'.e, stated that at th^ rat-, ^f 1 T-io'ind t' frcn 1"^ to 100 gallons of water 
it hfi.d r^ivrn excollcnt rpsnlts, a?Tainst this ^r^pcies, 
Mclnd'^o and Sievers (265) in 192^^ r^n'^rtp- tha^- cuIdp j^nd d'rris 
■lusts, alsn the crld alcoholic extract nf cute with soap, w^re pffecti'^e 
afrainst potato "beetle larvae. Ar. alcoholic extract of derris, with soap, 
WR8 inefficient a,'-;ainpt the larvae and adults, 
Kelsnll et al. (2UU) in 1926 putlished th'- results of tests on 
Colorado '••otnto "beetle larvae with derris iti U— U-Uo 'bordea'-'jc, derris 
and hydrated line, and derris alone, which led to the following conclusionst 
Derris is effecti-^e in loth spray »nd dust for'nst derris kills more rar^idly 
thai! the arsericals: derris is less effecti-'-e when 'nixed with hydrated li'ne, 
and 'still loss s-^^ when nixed with l)ordeauy-. To got the sane eventual kill, 
1 pound of derris is appare'_tl^^ about equivalent to from 1-1/2 to "^ p'^imds 
of calciun arsenate. These workers re^rardel derris as a contact _rois''n 
only, 
Davidson (^) made tests -.n potato plants in the fi'^ld in IS'^O and 
obtained the following: results with sus^.'Cnsi^ns ^f rotr-n-ne i:\ water: 
Insect iatc.ge C'-ncftntration 
Mortality 
53,: cc. 
Adults 1:2,000 
Percent 
^0.0 
Adults 1:5 000 
Adults l;10,'00 
12.0 
0.0 
Ef-,.--p 1:30,000 
100.0 
Snail lnr'^n.e - 1:70,000 
95.0 
Larc/e l?rve,e-- HID, 000 
96.S 
Lare>3 larvae-- -i: -iU'; 000 ' 
9^.4 
Little (26]^, 262 ) in 19^1 rco-rt-d excellent control (96.8 percent 
kill) of C'^lorad'-. potato "beetle Ir^rvae feedin*: on ef;^.'.xl?)nt in the field, 
"by usin.--; root of devil' s-shoestrinfrs ( Tephrosia virg^iniana ) at U pounds 
per 100 gallons of water. 
Canp'^ell (66) in 1932 critically reviewF.d tests nade ty Davidson 
with roten-^ne ^n the Colorado pot^^to bertl*- . Rotenene- 9usr>ende3. in water 
1:200 sprayed on leaves and fed to t^c- adults as a sandwich killed all; 
at 1:1,000, feeding was curtailed; beetles -n a "lant srrayed with rote- 
none 1:10,000 were not aff^^cted. Davidson also made an er^erinent with 
rotenone to test its rer.ellent effect afCainst Colorado potat^i beetles. 
T'^e insects were :ivrn an or-rortunity durinc a period ef 5 h-^urc to f-^ed 
on potato-"' eai sp.ndwichos c':^ntaininp: roteni^ne. Thereafter the" were fed 
untreated leaf disks for '- days. The nr^rtality was ne, lir-i"ble tut it was 
observed that the? booties ate less ef the r^ten^ne eendwiches t^ian ■^f these 
cntaininit; lead arsenate. On the following day the beetles that had 
taken rotener.e ate less untrer.tfMl foliafce tha.n lid th^se that had taken 
lead prsrnate, Davics-i^n, therefore, suBf-f^cted a rer^elle.-t acti'n of reten^nr, 
but Csmpbell believes that no renellent action was de'n-^netrated. The beetles 
probably at^ sublethal doses ef rotenone and were affected t*" the extent that 
they were una'^le to fef'd nonally. on untreated lepf disks until they hpd r<»- 
covered. Und'ubtedly the sane eff'-ct could hav-~ '^(?ct. produced with lead 
arsenate if larr~or sublethal d'^s'^s hpd bern taken. 
