, Cooperative extension bervice, university 01 



J- ^ / Illinois College of Agriculture in Cooperation With 

 the Illinois Natural History Survey and U.S.D.A. 



FOR IMMEDIATE RELEASE June 3, 1966 



INSECT SURVEY BULLETIN NO . 7 



This seventh weekly "bulletin 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 cooper- 

 ating agencies, reports general trends in insect activity and suggests abbrevi- 

 ated control measures. Each individual should check his own fields to determine 

 local conditions. 



Present Farm Insect Problems 



Armyworms are present in potentially damaging numbers in occasional 

 rank stands of wheat, barley, rye and grass in the southern half of Illinois. 

 Some fields of thick wheat averaged as many as 5 or 6 worms per linear foot of 

 drill row, but this is still a borderline count for treatment. In lodged spots, 

 counts were as high as 11 worms per linear foot of row. The infestation is 

 spotted and is not so severe as in 19 6U, when 15 to 30 worms or more per foot of 

 row were common. 



South of Highway 50, armyworms are large enough for treatments to be 

 applied immediately. In the area "between Highways 5"0 and 9 > most of the worms 

 are still small (l/4 to l/2 inch) and treatments should not be applied until 

 June 10. 



Damage from mice or other rodents is noticeable in wheat fields. They 

 cut the stems in 3- or i+-inch lengths and leave them in piles. This is not the 

 work of armyworms, which strip the leaves and beards and sometimes cut the stem 

 just below the head. 



The greatest mistake in armyworm control is to panic and apply insec- 

 ticides too soon or when they are not necessary. Do not use insecticides unless 

 there are enough worms to justify treatment. Do not make applications unless most 

 of the worms are l/2 to 1 inch long. An armyworm eats 80 percent of its food 

 supply in the last four or five days of the worm stage. Predators, parasites and 

 diseases also take their toll of small armyworms and can lessen the threat in a 

 few days. Occasional off-colored armyworms suspected of having disease were found 

 this week. 



If there are six or more armyworms l/2 to 1 inch long per linear foot 

 of drill row, treatment is suggested. 



Apply 1 1/2 pounds of toxaphene to control armywcnns in small grains. 

 There are no restrictions on use of the grain. Do not feed the straw to dairy 

 animals or to livestock fattening for slaughter. Do not apply toxaphene to fields 

 adjacent to dairy pastures or hay crops. Do not contaminate fish-bearing waters 

 with toxaphene. We have suggested that dairy farmers not use chlorinated hydro- 

 carbons on their farms. Toxaphene belongs to this family of chemicals, but the 

 official label permits its use on dairy farms. If you use it on or adjacent to a 

 dairy farm, avoid drift onto pastures and hay crops. Trichlorfon (Dylox), an 



