FOR IMMEDIATE RELEASE July 20, 1962 



INSECT SURVEY BULLETIN NO. lU J1J L 2 3 1962 



These weekly 'bulletins, prepared by entomologists of the University of 

 Illinois College of Agriculture, Illinois Natural History Survey and cooperating 

 agencies, report general trends in insect populations in Illinois (fruit insects 

 excepted). Check your own fields to determine local conditions. 



Grasshoppers : Now that grasshopper and their feeding damage are becoming 

 more apparent, we are receiving questions on various insecticides, rates of appli- 

 cation, length of effective control and speed of kill. 



There are some insecticides that we do not recommend but that do have 

 label approval for grasshopper control. When using materials not listed in our re- 

 commendations or for crops not listed, be sure you are using directions that are not 

 several years old. 



The amount of an insecticide that can be used per acre may vary, and in 

 some instances lower rates than we recommend may give good control. Our recommenda- 

 tions are made with the thought that the user will obtain good consistent control 

 over a wide range of grasshopper sizes, conditions and crops. Even then there will 

 be occasional failures under adverse conditions. Too low dosage rates will lead to 

 more failures when conditions are unfavorable. It is cheaper to use enough the 

 first time than to have to do the job over. . , 



Dieldrin, toxaphene and Sevin kill grasshoppers slowly. Do not evaluate 

 control for 2 to k days after treatment. Dieldrin and toxaphene provide control for 

 several days after application; Sevin, for only a few days. Diazinon, dibrom and 

 malathion kill a high percentage of 'hoppers within 2h to 36 hours, and the control 

 increases only slightly thereafter. 



Our recommendations for control are: For areas that will not be grazed or 

 used as hay for livestock, use l/8 lb. of dieldrin, 1 l/2 lb. of toxaphene, l/k lb. 

 of aldrin or l/k lb. of heptachlor per acre. This includes such areas as roadsides, 

 diverted acres, etc. 



On pastures for dairy animals and beef cattle, use 3/4 lb. of dibrom or 

 1 to 1 l/2 lb. of Sevin per acre. No interval is required between application and 

 grazing. (Note: To clarify this rate, 1 lb. of Sevin has given good control except 

 in one instance where control was extremely difficult and 1 l/2 lb. was required.) 



For pastures to be grazed only by beef cattle, use 1 l/2 lb. of toxaphene. 

 If toxaphene is also being applied to the cattle to control flies, allow k2 days 

 between last grazing on treated pasture and slaughter. Do not graze dairy animals 

 on toxaphene- treated forage or pasture. 



For hay crops, apply 3/k lb. of dibrom, 1 lb. of malathion or 1 to 

 1 1/2 lb. of Sevin per acre. No interval between application and harvest is re- 

 quired for Sevin. Allow k days when using dibrom and 7 days for malathion. Diazinon, 

 1/2 lb. per acre, can be used on alfalfa, with 7 days between application and harvest. 

 A single treatment of 1 oz. of dieldrin per acre may be applied to hay crops, but 

 not after the new growth is over six to eight inches high or within 35 days of 

 harvest. 



