24 ANNUAL REPORTS 01 DEPARTMENT OF AGRICULTURE, 1951 
sects. At a dosage of 2.8 gallons to L,000 bushels, it was also highly 
effective against immature stages of the rice weevil. This fumigant 
compared favorably with the standard 80:20 carbon tetrachloride- 
carbon disulfide mixture applied in the same < 1 < > - : i i_ r ♦ ■ ~ . 
Insecticides Control Sugarcane Borer on Large Scale 
In expectation of a severe infestation by the sugarcane borer in the 
spring of L950, the Louisiana State Legislature appropriated $25 . 
to assist growers in buying insecticides. Bureau entomologists co- 
operated with Louisiana State entomologists in the program bj cer- 
1 1 tying about L6,000 acres of sugarcane as sufficient ly infested to war- 
rant treatment. Altogether, about 62,000 acres in Louisiana were 
dusted with cryolite or LO-percent ryania. 
A.mong several insecticides tested against the sugarcane borer, a 
spraj of toxaphene :it the rate of 2 pounds an acre gave the best con- 
trol — an average of 97 percent — although several others were almost 
a- good. In general, a LO-percent ryania dust gave better control of 
the borer than a 7..'.- or L5-percent dust pin- 0.5 percent of either 
// propyl isome or piperonyl cyclonene a- a synergist. Dusts and 
sprays of LO-percent ryania were generally more effective than those 
of cryolite against t be sugarcane borer in Florida. 
Insecticides Control Legume Insects 
Recommendations have recently been published for the control of 
several important insect pests of Legume crops being grown for seed. 
In Utah lygus bug nymphs and adults and alfalfa weevil Larvae on 
seed alfalfa in bud are destroyed with 20 pounds of LO-percent DDT 
dust an acre or with a -pray containing L.5 pound- of actual DDT an 
acre. If a reirifestation of the Lygus bugs warrants a second treat- 
ment when the alfalfa is in bloom, 20 pound- of LO-percent toxaphene 
dust an acre or L.5 pounds of actual toxaphene an acre a- a -pray 
should he applied in the early morning or in the evening, when bees 
are not active in the field. To control adult- of the alfalfa weevil 
in the spring, when the first crop shoots ait' 1 to •_' inches tall, the ap- 
plication of a water-emulsion spray of chlordane at the rate of L.5 
pound- of chlordane an acre i- recommended. 
Ill Arizona dusts and sprays of toxaphene have been used to control 
Lygus bugs «'ii seed alfala in the prebloom stage. Ninety sis percent 
of the lygus bugs were tailed in one 80-acre field with an airplane 
application of the dust. Reductions of 95 t«> 98 percent of the bugs 
were obtained in six BO acre fields treated by airplane with an emulsion 
-] I] a \ of lo\a phene. 
The clover seed weevil in fields of alsike and white clover in the 
Willamette Valley of Oregon was controlled with a .'. percent DDT 
dust applied at i he rate of 20 pound- an acre. 
Excellent control of the potato Leafhopper on alfalfa was obtained 
in Maryland b) spraying with one half pound of methoxychlor an 
acre. Tin' crop thus treated showed exceptional growth and quality 
in comparison with the untreated crop, which was severeh damaged 
h\ the insect. Methoxychlor al-o gave good control of the meadow 
pit! lebuc i n one -ma II test . 
