-31- 
a dual-fixed niootine dust or a 1-percent rotenone dust, which yield- 
ed 86.5 and 81.6 percent uninfested ears, respectively, when applied 
with a wheelbarrow duster, and 90.3 and 89.2 percent respectively, 
when applied with a traotor duster.--Carruth (104 ) . 
Because it appeared probable that rotenone would not be avail- 
able for use on sweet oorn, and the manufacture of dual-fixed nico- 
tine dust was discontinued. A spray of derris (5 percent of rote- 
none) with Grasselli spreader-sticker was superior to Black Leaf 
155, but the latter could be used during the war emergency in situ- 
ations where spraying was a practioal means of borer control.— Carruth 
(105). 
Of the various dust materials tested, dual-fixed nicotine dust 
(4 percent of nicotine) and 1-percent rotenone dust were the most 
consistently effective and did not differ greatly in titieir perform- 
ances under New York conditions.— Parrott (457) . 
Nicotine was not entirely satisfactory. Rotenone was more ef- 
fective against the European oorn borer on sweet corn.— U. S. Bureau 
of Entomology and Plant Quarantine (628 ) ♦ 
In 1943 the most satisfactory insecticide for use against this 
pest in dahlias contained derris, cube, or niootine •— Batch elder and 
coworkers (37). 
Spray treatments of market sweet corn with high- clearance boom 
equipment provided greater numbers of borer-free ears, with 40 per- 
oent less derris per acre, than did the dust treatments.— Quest el 
and Irons (486) . 
Differences in tenacity determined in the laboratory indicated 
that derris dust resisted about six times as much washing as did 
dual-fixed nicotine dust and it should therefore perform relative- 
ly better in seasons of a high amount of rainfall .—Turner (605) . 
In commercial-scale trials of a derris spray at Toledo, Ohio, 
and of a derris spray pnd dual-fixed nicotine dust at New Haven, 
Conn., at costs of $19 to $24 per acre, these treatments showed a 
new profit of about $400 per acre from increased yield and reduc- 
tion in corn borer infestation of early sweet corn.— U. S. Bureau 
of Entomology and Plant Quarantine (628 , p. 133). 
In 1944 the conclusions drawn from commercial insecticide tests 
follow: (l) Derris spray was considerably more effective in corn 
