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raade in 1936 and . 1937 several brands of pyrethrum powder and 
cube powders applied in a mixture of summer oil, 1:200, as contact 
insecticides. In general, results on exposed tent caterpillars 
were better than on this species. In 1932 these authors ( 127 ) 
reported on a comparative test conducted in May 1937, of lead arsen- 
ate, cryolite, and derris-resin-residue emulsion. A woodland border 
comprising deciduous trees up to 80 or 90 feet maximum height 
whidh were lightly infested with the young caterpillars, was spray- 
ed with power sprayers. The derris powder (J+ percent rotenone and 
15 to 16 percent total ether extractives) was applied at the rate of 
U pounds to 100 gallons plus rosin-residue emulsion at 2 quarts to 
100 gallons; Kryocide cryolite at k pounds to 1C0 gallons plus S.S.S. 
Spreader at 2 pounds to 100 gallons; and lead arsenate at 5 pounds 
to 100 gallons plus 0.5 pound of S. S. S. Spreader to 100 gallons. 
On the young larvae a good initial kill was obtained with all three 
materials, the most lasting protection being obtained with lead 
arsenate. 
McDaniel ( 260 ) in 1938 reported on control on elms in Michigan. 
All sprays were applied under 600 to 800 pounds pressure at the 
nozzle. None of the sprays caused injury to the foliage. Results 
were good with cube and derris applied in June 1937 at the rate of 
3 and 4. pounds, respectively, plus 3 pounds of rosin residue per 
100 gallons of water. No live larvae were found on sprayed elms 
at the end of 72 hours, but they were numerous on the checks. 
Bupalus piniarius (L.) 
See Tragfirdh ( 4-16 ) under Panolis griseovariepata , page 92. 
Weis ( 477 ) in 1931 reported that fifth instars were very 
resistant to Polvo but the effect of the poison was noted in a 
decrease in the amount of excrement. 
Schwerdtfeger and Stahl ( 367 ) in 1937 reported tests made in 
1936 with 12 proprietary contact dust insecticides against larvae 
of the pine geometrid in Prussia. In the laboratory, batches of 
^0 larvae were dusted in the Lang-Welte apparatus [Rev. kppl. 
Ent. (A) 1°: 701 1 with quantities corresponding to about 45 pounds 
per acre, fed on untreated material, and examined for mortality 
after 2 days. Seven insecticide-: based on derris, pyrethrum, or 
veratrine caused average mortalities ranging from UU to 100 per- 
cent, while 5 based on dinitrocresol gave 100-percent mortality. 
The effect of the latter w- s confirmed in further tests, in which 
almost complete mortality was obtained in 2 hours. In field work 
between July 20 and August 20, the insecticides were applied by 
power dusters at the r p .te of IS pounds per acre in unmixed pi 
stands, each test area covering nearly 2-1/2 acn s. roup 
of 7 insecticides gave average mortalities of 30-79 percent, -! 
the 5 dinitrocresol poisons gave mortalities of from 90 to 99 p ^r- 
cent. The latter caused slight scorching of the pines, but only 
when the amount applied was excessive. 
Chcimatobia brumata ( I. . ) 
Gimingham and Titter sfield (161) in 1928 found I ictracts of 
