• - 54 - 
ITonpoisonous dusts -were a] so us-ed on the Mexican "bean "beetle and 
the cherry slag. A dust containing 0.75 percent rotenone used on the fcean 
beetle failed to give satisfactory control. A spray of rotenone, 2 pounds 
of derris containing 4 percent of rotenone to 50 gallons of rater, gave 
control equal to that effected "by arsenite of zinc and -arsenate of 
magnesium or pheno thiamine, 2 pounds to 50 gallons of water, under heavy 
infestation. On the cherry slug, rotenone sprays, with 2 pounds of either 
derris or cube powder containing 3 percent rotenpnp to 50 gallons of water, 
gave controls equal to those effected "oy arsenate of lead. 
The Texas Agricultural Experiment Station (403) in its 1936 annual 
report (published in 1037) reported on remedial measures for the pink 
bollworm. Seasonal infestation courts indie -ted that barium fluo silicate 
and cube-sulphur used separately as dusts or sprays reduced the worm 
population. This was more apparent on the olats dusted with barium flue- 
silicate. Further investigations are necessary to determine the merits of 
insecticides for pink bollworm control. 
Bespits in two series of experiments indicated that there was very 
little difference between sulphur and fuller's earth when mixed with cube 
for the control of the cabbage looper. 
The Idaho Agricultural Experiment Station (211) in 1937 reported 
that a kill of 94.31 percent of the grape leafhopper was obtained with one 
spray containing 0.49 percent nicotine sulphate and 0.63 percent summer oil. 
Better and more lasting results wore obtained with this combination than 
with derris or cube powder in either dust or liquid form or with pyrethrum 
spray. Derris as a spray was more effective than as a dust. 
Huckett (206) in 1937 recommended derris or cube for the control of 
the asparagus beetle, Crioceris aspa ragi L. , and the spotted asparagus 
beetle, Cr ioceris d uo d ec impunc t ata L. In beds injury may be prevented by 
spraying or dusting the tips thoroly with derris mixtures during the cut- 
ting season to kill beetles and slugs. As a spray use 5 pounds of derris 
and 4 pounds of skimmilk or Kayso to 100 gallons of wa.ter. As a dust use 
15 pounds of derris to 85 ucunds of clay or talc. Use powdered derris root 
of 4 to 5 percent rotenone content and 15 to 18 percent total extractive 
content; or, if derris is not available, substitute powdered cube or timbo 
root of comparable analysis. 
Kearns ard Umpleby (237), of the Long Ash ton Research Sta.tion, 
England, in 1937 reported that grafts can be effectively protected from 
weevil injury by liberally painting them with a mixture consisting of 1 
pound of derris or barba.sco ground root containing not less than 1,5 per- 
cent rotenone, plus 2 pounds of lead arsenate powder (or 4 pounds pa.ste 
or 2 quarts colloidal), plus 4 ounces of size. The derris and arsenate 
should be mixed with water to a consistency of thick creau and to this 
mixture the size added (previously soaked in 1 pint warm water). The 
grafts should be painted just prior to bud burst, and in some sea.sons a 
second application may be necessary, as the leaf weevils feed over a long 
period. These weevils are the clay-colored weevil, Otiorrhyr.chus singularis, 
