Livestock Insects 



Flies on pastured cattle are increasing in number and are causing noticeable an- 

 noyance to the animals. In southern sections, there is an average of 40 to 250 

 horn flies and 2 to 4 stable flies per animal. In northern sections, there is an 

 average of 25 to 50 horn flies, 1 to 3 stable flies, and 2 to 10 face flies per 

 animal. 



Start fly control rather than waiting until the problem is severe. Thus far, 

 weather has been favorable for high survival of stable flies and maggots which 

 forecasts a severe fly year. Stable flies prefer wet and rotting straw in which 

 to deposit eggs, as their maggots survive very well in this material. If the 

 weather remains moist and humid throughout the summer, stable flies will even 

 develop in moist rotting vegetation in fence rows and fields. Piles of discarded 

 hay or grass clippings also provide an incubator for these stable flies. 



Right now remove wet straw and hay from the barns and barn lots. Scatter it to 

 dry before the stable flies use it as their egg incubator. A bit of sanitation 

 now may prevent a severe problem later. 



For dairy cattle, apply Ciodrin, dichlorvos (DDVP) , or synergized pyrethrin sprays 

 daily or twice a week depending on amount used per animal. For beef cattle, use 

 toxaphene every 3 weeks or Ciodrin in an automatic sprayer. Do not apply toxaphene 

 within 28 days of slaughter nor to calves under 4 months of age. 



PLANT DISEASES 



Corn 



Corn smut has killed young plants in some fields in central Illinois. The damage 

 occurs only in the low areas of fields . Stand reductions in the damaged areas of 

 as much as 50 percent have been observed. The smut infection occurs below the 

 soil line and results in typical white smut galls on the base of the plant. The 

 above-ground symptoms are: (1) stunting of the entire plant, (2) wilting of the 

 leaves followed by death of leaves, and (3) death of the plant. Some galls ex- 

 tend above the soil line and cause considerable distortion of the plant. This 

 can be distinguished from herbicide injury by the presence of the smut galls. 

 There apparently is no evidence that herbicides predispose the plants to infection. 

 Damage to corn seedlings by smut is a little unusual; however, such injury was 

 noted in Indiana last year and again this year. 



Wheat 



Leaf rust has increased rapidly during June and is very heavy in some fields at 

 this time. Some fields have had all leaf tissue killed by a combination of damage 

 from Septoria leaf blotch, powdery mildew, and leaf rust. If the leaves are 

 killed while the kernels are still in the late milk stage, reduction in test 

 weight and possibly in kernel size can be expected. Benhur is apparently resistant 

 to the races of the rust found on the other varieties. Very little stem rust has 

 been observed. 



