- 32 
Yipld Copt of i:at>--rial 
Trf^at'-^-cnt V/ilt ^''-r acr- 
"orr aero 
Prrcent Bushels D-^llaJ 
'Calciim arsonatr- 2 lus. 
ccp^f^-r oxvchloride 3 
Ids". , vat -- r 50 gal . 3.6 1 , lU? $8 . 6U 
Derris dust (0.75 "^^r- 
cent rotpnor.e) . " 15.5 S20 88. SS 
Check 30.0 39 ^ 
Kovrard p.nd Mason ( 198 ) in 1937 referrr^d to the vrork of other in-'-.-'sti- 
gators vrho ha'^e fonjid that derris and cul'e are vory eff^cti'f^e in tho control 
of cucionlDf^r "beetles. 
Derris dusts h?.ve .<iv?n satisfactory 'ri^sult? on cucun'b'^r ''jec-'tles. — 
Now Jrrse:' Ar:ricultural SyrTrinont Station ( 297 ) in 1937. 
The Uev York Coiii-ty Argents' Trainin.-? School ( 3OO ) in 1938 sade 
the following recoauendation for the control of cucurnoer "beetles: Use 
1 percent of rotenone if arsf'-nate-lime dust is not satisfactory. It kills 
and is ?lso a s^od repellent, uut -nor'' eyrcnsive. Treat the whole field 
at once. 
Epitriy cuc-JJ'ierig (Harr.), tiie -^otato flea "beetle 
See reports on the control of Epitrix parvula (F.) "by Cham"berlin 
and Ma,dden ( 77) ? ?nd the Unit^^d States Dc-^artaent of Agriculture, Bi-reau 
of Entomologj' and Plant Quarantine annual r^-oorts for 1937 ( 39^) and IQ3S 
( 398 ) on pages 32, 38, Ul, ^+2, and U3 respecti^rely. 
Anderson ?ind Walker (15_) in 193^ reported the results of field tests 
on thp Ea=:tern Sh^re of Yir^^inia for the control of the potato flea "beetle 
vrith calcium arsenate-hordeaiiy sr.'ray (2-U-6-50) plus derris dust (1:7? 
with derris dust (l!3) ^■^''•^- also (1:7); and vrith concentrated derris extract 
(1:^00). Some striking results were ottaincd with derris products, "both 
spray pjid dust, v^hen used on a small scale. Kills of hett^^-r than 90 per- 
cent wore o"btained with ca-r^-'^d "bertles treat-^^d with a derris dust contain- 
ing 0.5 10'^rcent of rotenone, or with a concentrated derris extract with 
5 gm, of rotenone rier 100 cc, , diluted 1:U00. Waen these materials were 
Used in the field good kills were also ohserved, "but p'=^rnanent protection 
vras not given and the "beetlrs migrated in fro^a s\irrounding unsTorayed plats, 
causing c^nsidera'ble in.jury. 
Lacroiy (2^) in 1^35 reported on tests in Connecticut in the aumi^er 
of 193^ with -oyret'irum dust, 8 pounds per acre, Cuoor dust (0,5 percent 
of rotenone) 8 pounds per acre, and "bariun fluosilic^te 6 pounds -nrr ecre, 
for the control of the r^otpto flea "beetle, wit'i onlj'- one applic=)ti^n of 
each materifil. Pyrethru-n and rotenone were both toxic to the potato flea 
"beetle, "but their potency wa=- lost within a few days efter eyoosure to the 
atmospherf. These tests indicated that during a rainy s'^ason, in which 
several applications of dust are necessary, any of the t"nr'-^e dusts v/ould 
undoubtedl- gi-o-e good control. 
