IkJ- 



COLLEGE OF 

 AGRICULTURE 

 UNIVERSITY OF 

 ILLINOIS AT 

 URBANA-CHAMPAIGN 

 AND NATURAL 

 HISTORY SURVEY 

 URBANA. ILLINOIS 



-JSECT, WEED & PLANT DISEASE SURVEY BULLETIN 



iTE/COUNTY/LOCAL GROUPS/U.S. DEPARTMENT OF AGRICULTURE COOPERATING 



FOR IMMEDIATE RELEASE 



No. 13, June 25, 1971 



This series of weekly bulletins provides a general look at the insect, weed, and 

 ■plant disease situation (fruit and eommeroial vegetables excepted) , along with 

 suggested, abbreviated, control measures. Each individual should check his own 

 fields to determine local conditions. 



INSECTS 



THE. UBRARY Of THE 



SEP 3 1971 



LIVESTOCK INSECTS 



Face flies . This insect increased rapidly in number during the last two weeks. 

 This pest is now bothering pastured cattle. The state average this past week 

 was 25 face flies per animal, with individual herds averaging as high as 60 per 

 animal. Face fly populations have been on the increase again since the summer 

 of 1969, and this summer could well be the worst yet. 



Infested cattle often develop eye problems , besides the constant irritation caused 

 by the flies. Face flies may also transmit pinkeye disease among cattle. 



For control on dairy cattle, apply a 2 -percent crotoxyphos (Ciodrin) oil -base spray 

 (if available) or a water-base spray at 1 to 2 ounces per animal, as often as once 

 a day if needed. In order to prevent another buildup, continue to apply the cro- 

 toxyphos two to three times each week, even though the number of flies may be low. 

 A 1-percent crotoxyphos, water-base spray- -applied at 1 pint per animal per week- 

 is also effective. This treatment is most practical for young stock and for dry stock. 



Preliminary results from three dairy farms using forced treatment with dust bags 

 containing 3 -percent crotoxyphos indicate that this method does not control face 

 flies. For pastured beef cattle, the 1-percent crotoxyphos, water-base spray- - 

 applied at 1 pint per animal per week- -should be considered. An automatic chute- 

 type sprayer using 2-percent crotoxyphos in oil is another good choice. Other- 

 wise, use a head or back oiler, wrapped with canvas or burlap and saturated with 

 a 5-percent solution of toxaphene in oil. This will afford partial relief from 

 face flies. Keep the oiler in good repair and well saturated. Do not apply 

 toxaphene to beef cattle within 28 days of slaughter. 



Feed additive insecticides like ronnel or phenothiazine used in mineral supple- 

 ments or salt blocks will not reduce the number of adult face flies bothering the 

 cattle . 



SOYBEAN INSECTS 



Mites. Two-spotted mites and related species do attack soybeans on occasion. They 

 scar the leaf, giving it a speckled appearance. These mites spin tiny webs; when 

 they are extremely abundant, the soybean leaves are noticeably webbed. If dry 

 weather persists, this can be a serious problem. 



Control is difficult. The spray must hit the underside of the leaf, where the 

 mites are, and must penetrate the webbing. 



