-15- 
in a heavily infested nursery block and therefore adjacent to in- 
fested unsprayed trees. On October 14-, results were as follows: 
After rotenone sprays (several dilutions of rotenone-bearing prop- 
rietary sprays and 2 pounds of 3 percent rotenone dust in 50 gallons 
of water with and without spreader), the trees were heavily infested. 
Results obtained with rotenone dusts have been variable* The best 
kill, 73.3 percent, was obtained with a 0.75 percent rotenone dust 
applied late in tha summer. — Langford (247) in 1937. 
Keiferia lycopersicella (Busck.) the tomato pinworm 
Barfoot. (23) in 1935 wrote as follows: 
Due to the rather outstanding results being obtained 
in the control of the pea leafminer by the use of standardized 
rotenone liquid sprays, it is this writer's opinion that if 
the same procedure were adopted on the tomatoes, this material 
would go far in the way of controlling the 'pinworm; 1 however, 
I strongly recommend spraying early and as often as every 10 days 
from blossom time until maturity. 
C. A. Thomas ( 4.07 , 4-08 ) in 1936 reporting on tests made in Penn- 
sylvania, said that the larvae were easily affected by dcrris, pyre- 
thrum, cube, and nicotine dusts and sprays, and proprietary insec- 
ticides containing these mat ; .ri r ls or extracts of them in combination 
with various carriers. Ground der'is and cube root (2 to 4- percent 
rotenone) and mixtures of these with carriers such as dusting sulfur, 
bentonite and inert C, also are toxic, although the larvae die quietly 
without the violent reaction and strong regurgitation characteristic 
of pyrethrum effects. Tomato le?.ves dusted with a derris pc-der 
containing 4- percent of rotenone were still toxic to these larv?e 
at the end of U weeks, although the plants wera exposed in a window 
during that time. After the tomatoes have begun to form, such ■ 
c- ntact materials as derris, rotenone, pyrethrum, or nicotine dusts 
and sprays should be used. These materials, especially derris, 
containing several percent of rotenone, ire very toxic to the larvae, 
and will kill them or. brief contact. PTany proprietary dust? contain 
too low a percentage of rotanons to b very toxic. Treatments - ith 
any of these rrateri^ls should begin with the srcrll seedlings and be 
repeated at int rv-ils of - week or 10 days. 
The Pennsylvania Igricultural Experiment Station ( 327 ) in 1937 
stated that dusting with sulfur-clay-dcrris-lead ars>:< - . good 
control. 
Elmore (j_lp_) in 193S reported testa of insecticide at Alh imbr . 
Calif. Cube extract was ineffective. Cryolite and cuprous cyanide, 
in either sprays or dusts, w. re t! most effective. 
Haude in 1939, in advertising literature, published by John 
Powell and Co., New York, N. Y., cited Thomas of Pennsylvania , -ho 
found derris dust very toxic to young l-:rvae. 
Pectinophora gossypiella (Saund.) the pink bollv.orm 
