-U5 - 
Thff Haw York State Agricultural Ixioerl'^ent Station ( 303 ) in 193? 
report-^d that a rotcmnr epray in rpparf^ntly vf^ry eff'^ctivc in thr control 
of the r-lin lenf "ber^tle. It h?,P the ?dvrntsgc of Inaving no vipiblp r^-sidu^ . 
on the foliagr Bi\d. also avoldx thf^ poaoibility of etainin;:: painted surfac^?. 
Gn-nbrell ( 15U ) in I9U0 recorded tests for the control of thf ^In 
leaf "b.^f^tlp vith cute povdrr (U r^rcp-nt of rotenonc) at ^ pounds p'=r 100 
gallons plue ^ ounces tii-181; d?rris powder (5 percent of rotenon.-') at U 
poundn per 100 gnllon? plus 1 pint of soytean oil plus 1 po^ond of BindefinG! 
(&oulac); stabilized derri? powder (from the Unitod Stater, Rubber Co-ir.ony) ; 
with the fla-r.c naterialg; and both re^nilar and stabilizrd derris powd-^rs 
plus either so^beRn flour (l pound) or &ragselli Stic'crr-Srread*^r (l/2 -nint). 
Irperinents in I93S indicated that spra"8 containing either k pounds 
of cube powder or 6 ps^onds of lead ar<*enate to 100 gallons of water wr>re 
effective when applied after n^re than half of the e^^s h?,d hatched. In 
1939 spray nirtures c^ntaini: g ritht-r derris (2 or U pounds) or lead primate 
(U or 6 pounds) in 100 gallons of wat<^r gave satisfactory control if nppliod 
on or after the second week of June, Limited test? with 2.5 percent of rot- 
enrne extract, diluted I'.^^OO, effected a hi.rh degree of control of both 
larvae and adults. In field tepts no appreciable differences wer-^ noted 
between th<^ effpcti'-eness of re^-lnr derris and that of stabilized derris 
(containing an pjati-oxidrnt) , with the possibl- exception "f the influence 
on the unhatched eggs. 
The advantages of derris powder or rotenone extract aprai^'s appear 
to include the l?.ck ^f cbjectionatle residue; relative saf-ncss to -^an and 
pets; and rapidity of kill. The latter point is of particular i-^.portanca 
when sprays are applied rather lat:^ in the season when nany Iprv^^e are 
second or third instars and i-nediate relifef from foliage injury is desired. 
The main disadvantat'es a.re thp dang-^ r of poisoning fish, cost '^f the nat-riril, 
and possi .le leek of adhesion rn foliage during heavy rains ^r wet we?th'°r. 
This latter objecti'^n may not r^ro^e t'^ be s-'^ri'^us, inasmuch as the materi-sl 
flh'^uld be applied to the iind>?r surf?5ce of the lepf bvA also because if the 
fact thet much '^f its ef f «. ctiveness apparently result*? fr-^'-" the contact 
action of the spray within a short tiie aft-^r application, 
Lema ^ryzae X\iw. 
Kuwayama ( 2^0 ) in 19;^6 gave a detaiL-^d historicf>l account --f th-- use 
of insectici es for the contr-1 of this insrct -•n rice in Jar-an and of ex- 
periments made durin/.- 1930-3^ in Hokkaido, A spray of 6-2/3 o-.inces of 
pyrethnam and 5 oimces '^f soap in 10 gallons -^f water proved vry effpctive 
ac^ainst the ergs, larvae^ and adults; and one of nicotine sulfate and soap 
was more eff'^cti^e than derris, 
Lema trilineata (Oliv.), th^ three-lined potato beetle 
The three-lined potato bentle was controlled by a dust a-nplic ti'-'n 
of a 50-50 mixtiu*e of derrin and hyrjat^d lime, — Kelsall et al» (2^^0 in. ''^ 
1926. ,_- '--"^ 
