-12- 
of 1 pound of ponder to 25 gallons . of water; soap was added at 
the rate of 1 ppund to 50 gallons, ~nd a knapsack sprayer was used. 
''.'ithin 24. hours the larvae became inactive and ceased to feed, and 
at the end of 6 days no livin? ones could be found. !-.s a check 
on this test, powdered lead arsenate was applied at the rate of 
1 pound to 50 gallons of water, and almost identical results were 
obtained. In a second test a small tree was sprayed and 24 hours 
later about ^0 larvae were placed on it. The caterpillars ate very 
little and gradually disappeared, evidently leaving the tree, and 
at the end of 5 days they were nearly all gone. — l/clndoo, Sievers, 
and Abbott ( 264 ) in 1919. 
Kopp (242) in 1924 in a review of the use of derris as an insecti- 
cide stated that derris powder has given excellent results against 
this species when used as a spray (500 gm. to 100 liters containing 
250 gm. of soap. ) 
rotts and ".'hitten ( 337 ) in 194-0 described tests with concentrated 
mixtures for aerial spraying. In order to determine whether certain 
concentrated spray mixtures could be successfully applied from the 
air, and to study the comparative merits of various spreading agents, 
adhesives, arsenicals, and substitutes for arsenic^ls in concent- 
rates, 22 mixtures war:-: sprayed on woodland plots from an autogiro. 
Fresh foliage from most o" the plots was fed to fourth and r i-"th 
instars. The degree of control was determine"' by comparing the 
amounts of frass passed by l°rvae feeding on sprayed ana on un- 
sprayed foliage. These foliage samp" 1 . ? were taken 1 to r 6 days 
after treatment and in all cases the spray residue was sufficient 
to kill some of the larvae. The arsenical sprays were more toxic 
than th : organic sprnys after the longer periods o^ exposure. The 
toxic principles of derris, derris extract', nicotine sulfate, free 
nicotine, and quebracho-fixed nicotine remained on thi -'oliage 
in effective quantities after 2 to 3 weeks 1 exposure.. With the 
exception of lime-sulfur none o p the mixtures caused any injury 
to foliage of wild black cherry. The following derris nr xtures 
were tested: (l) Derris 1, fish oil 0.4., water C .G\ (2) derris 
1, fish oil 0.2, spreader B (water- soluble sulfonic acid o p pet- 
roleum) 0.07, paraffin oil 0.2, water 5; and (3) derris extract 1 # 
acetone 1, fish, oil 4., spreader i\ (alkylphenylbenzene sulfonic acid.) 
0.", w?ter 37. The derris powder contained 4 percent of rot none 
and the derris extract 2 C percent. 
Coleophoridae 
Coleophora l-.ricella (Hbn.), the larch casebearer 
Kelsall eb al. ( 233 ) in 1926 reported that derris, both dust 
and spray, gave a measure of control. 
Hamilton ( 180 ) in 1938 reported that on larch trees 75 percent 
were controlled by a spray of derris or cube powder (4- percent 
rotenone) at 4- pounds per 100 gallons of water plus 4. pounds of 
rosin-residue emulsion. The spray acts as a stomach poison. The 
effective period is 3 to 4 days. Results are slow. These results are 
r if erred to in the 1938 annual report o r the New Jersey Agricultural 
Experiment Station (294). 
