-80- 
derris (• 5 percent rotEnone) end pyre thrum: (0.9 pereent pyre thr ins) . Flies 
were obtained in March.- and April from pupae in en incubator end *-ere dustei 
with definite Quantities of insecticide in a cege of measured size, in an 
attempt to determine "hich "as the more effective dust and to approximate 
the lethal dose needed in the field. The- temperature ranged frcm 65° to 
70° F. Pyre thrum used at the rate of 90 mg. per cage ( 1/3 cu. ft.) killed 
the flies in 20 hours. Derris at the rate of 30 mg. per caee ( 1/3 cu. ft.) 
killed the flies in 3-1/2 hoirs, and in tests "ith smaller ouantities it 
-•as found that 5 mg. to a. cege "ouid inca-oecitr te flies "-ithin 2 hours and 
they "ould die without regaining motive po^er. No smeller dosages Tere 
tried. Five mg. to 1/3 cubic foot "Ould he eoual to 4-1/3 pounds per acre, 
treating a space 3 feet high, or 8-2/3 pounds per- acre for a space 6 feet 
high. The treatment finally recommended '-'as 10 pounds per acre for small 
plants and 15 pounds r>er acre for larger ones. Commercial treatments "ere 
made on 225 acres representing plentings of 10 different growers. Some 
operators used a monoplane and others an autogiro. The dosege "as limited 
to 10 to 15 pounds per acre. T"0 small cages, 4 by 10 by 2 inches, of 
folded- ,rT ire mosouito screening, were used to hold flies in -the center of 
large bushes in fields that were being dusted by eutogiro. Six flies were 
used in a cege, and all '"ere deed "ithin 2 hours after treatment. Adults 
of Rhagoletis pomon^lla cen be killed in cultiveted blueberrv plantations 
by dustine, from en eirplene or eutogiro, with 10 to 15 pounds of derris 
d.ust (5 percent rotenone) to the acre, -^he time for treetments' in New 
Jersey is approximately June 27 to 30, and July 7 to 10. 
The Connecticut Strte Agricultural Experiment Station (51) in 1937 
reported thet results of tests "ith various substitutes for lead arsenate 
in orchard sprays indicated that the best control of the apple maggot "as 
obtained on the trees in the cryolite-derris plot sprayed "*ith phenothiazine. 
Continued' "ork ^ith these materials appears to be desirable. 
Germen (93) in 1937 reported th-t in generel, the results obtained 
that year indicated that derris is a very good insecticide for killing 
apple maggot flies and that it kills much more repidly than lead arsenate. 
This rapid kill ™es also reflected in e reduction in egg punctures amounting 
to 99 percent "hen the materiel was used es a spray at the same rate as 
lead ersenrte. Smell auentities of derris or allied materiel in the form 
of e dust containing' 0.75 percent of rotenone, anplied so as to cover the 
fruit surfece in a verv light layer, "ore also effective in killing the 
flies end -preventing oviposition. Phenothiazine continued to sho" repel- 
lent action but in killing effect "as not cauel to either derris or lead 
arsenate. Wheat flour was used as a carrier in ell tests except that "ith, 
the rotenone dust, the sprays being applied at the rfte of 3 gm. of poison 
and 3 gm. of flour in 800 cc. of water. 
The Ne<" Jersey Agricultural Experiment Station ( 211 ) in 1937 reported 
that tests "ere made against this fruitfly infesting blueberries. Derris 
dust ?t the rate of 10 "mg. or more killed the flies in 3 hours. Five mg. 
of derris disabled the flies in 7 hours so thi t they eventually died. 
