BUREAU OF ENTOMOLOGY AXD PLANT QUARANTINE 35 
1-percent toxaphene or 1-percent chlordane at the rate of 400 and 200 
pounds an acre, respectively, than in untreated plots. At the same 
time there was a 14 to 31 percent increase in stand in the treated over 
the check plots. The most destructive insects were wireworms and 
the lesser cornstalk borer. In Florida tests, wireworms were best 
controlled with 2 pounds of parathion, 3 pounds of aldrin, 2 pounds 
of the gamma isomer of BHC. or 6 pounds of chlordane an acre. 
Improved Control Methods for Injurious Legume Insects 
Excellent control of heavy populations of the potato leaf hopper 
on alfalfa was obtained in Maryland and Ohio in several tests with 
methoxychlor at dosages ranging from 0.3 to 0.8 pound applied in 
5 gallons of water emulsion spray an acre. A dosage of 0.5 pound 
an acre applied about 3 weeks before harvest is being recommended to 
the grower. 
Tests in Utah with water emulsion sprays applied with a low-pres- 
sure field sprayer to alfalfa in the bud stage indicated for the third 
year that toxaphene at 3 pounds or dieldrin at 0.25 pound per acre gives 
good control of lygus bug nymphs for a 3-week period. Both of 
these insecticides were as effective as the now recommended DDT at 
iy 2 to 2 pounds an acre. Aldrin at 0.5 pound an acre furnished 
good control for 2 weeks in preliminary trials. Endrin and isodrin 
applied at 0.2 pound an acre and heptachlor at 0.25 pound an acre 
gave control of lygus bug nymphs similar to that obtained with DDT. 
A dieldrin water emulsion spray applied to alfalfa 1 to 2 inches 
high in the early spring at the rate of 0.25 pound of dieldrin per acre 
effectively controlled alfalfa weevil adults before they could lay eggs. 
Dieldrin is now being recommended along with chlordane for early 
spring treatment of both seed and hay alfalfa. In recent experi- 
ments the most promising insecticides against the larvae of the al- 
falfa weevil were aldrin at 2 ounce- and heptachlor at 2to ounces an 
acre. 
Emulsion sprays containing 0.75 to 1 pound of methoxychlor an 
acre gave good control of spittlebug nymphs in Maryland on alfalfa 
and red clover. The application of benzene hexachloride containing 
0.25 pound of gamma isomer per acre gave excellent control of the 
spittlebug on red clover in Ohio. 
Under Utah conditions DDT applied for lygus bug control on 
alfalfa is usually effective against the pea aphid on the same crop. 
When additional sprays were needed. 1 pint of 25-percent emulsifiable 
concentrate of parathion or 1 pint of 40-percent TEPP in 6 to 8 gal- 
lons of water an acre gave good control. 
Plot treatments in the fall with aldrin or chlordane as dilute dusts 
in Ohio effectively reduced infestation of the clover root borer, as 
determined by an examination of the roots in the following August. 
Extensive tests in southeastern Virginia, carried out in cooperation 
with the Virginia Agricultural Experiment Station, showed that 2 
pounds of aldrin or 25 pounds of toxaphene an acre applied immedi- 
ately prior to the first cultivation was effective in controlling the south- 
ern corn rootworm on peanuts. Neither insecticide when so applied 
caused off-flavor in the peanuts or in peanut butter prepared from 
the treated peanuts. Preliminary tests with dieldrin and hepta- 
chlor gave promising results. 
