FOR IMMEDIATE RELEASE July 19, I963 



INSECT SURVEY BULLETIN NO. Ik 



This is the fourteenth in a series of weekly bulletins on the general 

 insect situation in Illinois (fruit insects excepted), prepared by entomologists 

 of the University of Illinois College of Agriculture, Illinois Natural History 

 Survey and cooperating agencies. It is designed to forewarn people in Illinois 

 of impending changes in insect activity and to suggest abbreviated control meas- 

 ures. These reports indicate only general trends. Each individual should check 

 his own fields to determine local conditions. 



Grasshoppers are still hatching in hay fields and diverted acres in the 

 northern half of Illinois. The infestations are spotted but seem to be higher and 

 more general in the northwestern section. Here infestations are severe enough to 

 noticeably reduce hay yields in many fields. Furthermore these grasshoppers will 

 migrate to corn, soybeans and other crops when the hay is cut. 



Questions are being asked about the effects of the recent rains. Hard, 

 beating rains either kill or bury tiny, newly hatched grasshoppers but do not 

 affect them after they are two or three days old. 



Right now is a good time to control 'hoppers in hay crop fields. 'Hop- 

 pers are small, new plant growth is short and it is still possible to get good 

 coverage. Later, additional foliage will act as an umbrella; the spray will remain 

 on top of the plants, while the 'hoppers underneath will not be affected. 



For pasture or hay crops, use 3/k pound of sevin, 1 pound malathion, 

 3/k pound dibrom or l/2 pound diazinon per acre. Sevin does not require any wait- 

 ing period between application and grazing or cutting for hay, but with malathion 

 allow a 7-day interval and with dibrom a 4-day interval. Diazinon may be used 

 only on alfalfa, provided a 7-day waiting period is observed. For best results, 

 apply in the late afternoon. These four insecticides are the only ones recommended 

 for hay crops or pastures for dairy animals or livestock fattening for slaughter. 



If alfalfa or clovers are in bloom, apply insecticides only in the late 

 afternoon or early evening to avoid killing pollinating insects. If your sprayer 

 has been used for 2,4-D, clean it out thoroughly before spraying legumes or soy- 

 beans. 



For those areas that will not be grazed or used for hay, apply 1 ounce 

 of dieldrin or 1 pound of toxaphene per acre to control the small 'hoppers now. 

 In another week it may require 2 ounces of dieldrin or 1 l/2 pounds of toxaphene to 

 control them. 



For soybeans or corn for grain, use 1 to 2 ounces of dieldrin or 1 1/2 

 pounds of toxaphene per acre. Allow 60 days to elapse between application of 

 dieldrin and harvest. If corn or soybeans are to be used for ensilage, hay or 

 pasture, use sevin or malathion with a 7-day interval between application and har- 

 vest. Diazinon can be used on ensilage corn with a 1^-day interval between appli- 

 cation and harvest. 



In northwestern Illinois, hay crop fields, particularly alfalfa, have 

 leafhoppers, plant bugs, alfalfa caterpillars, pea aphids and other pests in them. 

 Treatment will control these insects along with the grasshoppers, improving hay 

 yield and quality. ^ 



M2 2m 



