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firebrats -when it was atomised into a Peet-^rady chamber. A talc dust 
depositing 20 mg» of EOT per square foot, or a Deobase-mineral oil 
spray leaving a residue of 80 mg. per square foot, gave complete con- 
trol of firebrats oonfined on treated surfaces for 24 hours. Residues 
(80 mg« per sq« ft») deposited from solutions in Deobase, cyclohexanone, 
or toluene, and those from aqueous suspensions, killed the insects, but 
more slowly than dusts.— Goddin and Swingle (179 ) . 
ORTHOPTERA 
Acrididae 
Camnula pelluoida (Scudd.), the clear-winged grasshopper 
DDT dusts and sprays gave good results. — Packard (285 ) . 
Melanoplus bivittatus (Say), the two-striped grasshopper 
See M. roexicanus .-Parker (286 ) ; Packard (285 ) • 
Melanoplus differentialis (Thos.), the differential grasshopper 
A 3-percent DDT dust (A-3) gave no indication of being toxic to 
differential grasshoppers when lightly dusted on them. The grasshoppers 
were swept from alfalfa and held in an insect net with alfalfa cuttings 
over night •--Smith (324 ) • 
A heavy infestation of grasshoppers in an alfalfa field treated 
with a 3-percent DDT dust at the rate of approximately 28 pounds per aore 
did not appear to be af fected.— Michelbacher et al. (257 ) • 
Melanoplus femur-rubrum (Deg.) , tiie red-legged grasshopper 
In dusts cevadine was more toxic than veratridine and both were more 
toxic than DDT,— ATP (66) . 
See M. m exi canu s .— Parker (286 ) j Packard (285 ) • 
M. m exi canu s (Sauss,), the lesser migratory grasshopper 
The dominant species of grasshoppers present in plots treated with 
DDT were Melanoplus mexicanus (Sauss.), M. bivittatus (Say), and M. femur - 
rubrum (Deg.) • No differences could be detected in their reaction to 
DDT dusts. The effects of DDT were apparent within half an hour after 
dusting. The grasshoppers became excited, descended from vegetation, and 
wandered aimlessly about manifesting distress. Many were down on their 
sides within 3 or 4 hours, but few were found dead the first day. In 48 
