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FOR IMMEDIATE RELEASE May Ik, 196k 



INSECT SURVEY BULLETIN NO. 5 



This is the fifth in a series of weekly bulletins on the general insect 

 situation in Illinois (fruit insects excepted), prepared by entomologists of the Uni- 

 versity of Illinois College of Agriculture, Illinois Natural History Survey and co- 

 operating agencies. It is designed to forewarn people in Illinois of impending 

 changes in insect activity and to suggest abbreviated control measures. These re- 

 ports indicate only general trends. Each individual should check his own fields to 

 determine local conditions. 



Alfalfa weevils have now been found in the following counties: Pope, Har- 

 din, Massac, Pulaski, Alexander, Union, Jackson, Johnson, Williamson, Franklin, Jef- 

 ferson, White, Wayne, Wabash, Marion, Lawrence, Crawford and Jasper. Larvae have 

 also been collected, and new adults should emerge in the most southern counties in 

 three to four weeks. We are not recommending control measures at this time, since 

 populations are extremely low. 



Potato leafhoppers appear to be more numerous than usual. Ordinarily there 

 are at least two migratory flights of these tiny green wedge-shaped insects into Il- 

 linois from the south. The first, which was heavier than normal this year, is com- 

 plete. The magnitude of the second flight will determine the importance of leaf- 

 hoppers for this year. 



Corn borer pupation is progressing rapidly. The overwintering borers are 

 rapidly transforming into the torpedo -shaped pupae. Pupation is complete in southern 

 Illinois; ^0 percent of the borers have pupated in the south-central section, 25 per- 

 cent in the central section, and 15 percent in the north-central section. 



The area in which borers could cause trouble this year lies west of a line 

 from Rockford to Joliet and north of a line from Joliet to Pittsfield. Although some 

 borers will be found readily in other areas of Illinois, control will not be profit- 

 able. 



Armyworms may appear in luxuriant stands of small grains or grasses in 

 southern Illinois. If you find six or more per linear foot of row, use toxaphene, 

 1 l/2 pounds, or dieldrin, l/k pound, per acre, for control in small grains. Allow 

 one week to elapse between treatment and harvest for wheat and rye, but allow lk days 

 when toxaphene is used on barley. Do not feed treated forage to livestock. 



Variegated cutworms may be present in numbers in clover and alfalfa fields 

 in southern Illinois. After the first crop is removed and before new growth starts, 

 apply sevin or toxaphene if worms are devouring the new shoots. Toxaphene should not 

 be applied to hay fields when growth is over four inches. 



Face flies are still not abundant on cattle, but questions are being asked 

 about internal medication with phenothiazine and ronnel for control on beef cattle. 

 These materials are mixed in feeds, mineral supplements, or salts. Their use greatly 

 reduces the number of horn fly maggots, and ronnel also reduces face fly maggots in 

 the fresh manure. Control of adult horn flies is satisfactory, since they do not mi- 

 grate but stay right on the farm where they are produced. However, ^ ] j»fi)ft € fcf f jf|jjP s 

 do migrate readily from one farm to another. Therefore, the use of ronnir^il rOTuce 

 the number of face flies only a small percent. Feeding phenothiazine ffifjtfbfag f$$ le 

 will have no measurable effect on face fly populations. Neither of these two mate- 

 rials is cleared for use on dairy cattle. (HHVERStfY If fUIN8t$ 



