t ' A^ 7 



COLLEGE OF 

 AGRICULTURE 

 UNIVERSITY OF 

 ILLINOIS AT 

 URBANA-CHAMPAIGN 

 AND NATURAL 

 HISTORY SURVEY 

 URBANA, ILLINOIS 



NSECT WEED & PLANT DISEASE SURVEY BULLETIN 



TATE/COUNTV/LOCAL GROUPS/U.S. DEPARTMENT OF AGRICULTURE COOPERATING 











FOR IMMEDIATE RELEASE 



No. 20, August 14, 1970 



This is the last in this series of weekly bulletins. We have tried to provide a gen- 

 eral look at the insect, weed, and plant disease situation (fruit and commercial 

 vegetables excepted) , along with suggested, abbreviated control measures . Each in- 

 dividual should check his own fields to determine local conditions. 



INSECTS 



GENERAL 



Grasshoppers are feeding on a variety of crops such as tomatoes, corn, soybeans, hay 

 crops, and many flowers. In fact they will eat most anything that is green if they 

 are hungry. They have been and still are migrating from fence rows, ditch banks, and 

 other areas. As hay is cut, they migrate from hay fields. Malathion or carbaryl 

 (Sevin) are two commonly used garden and flower insecticides that will control them. 

 These along with naled (Dibrom) and toxaphene can be used on soybeans. These four 

 insecticides and diazinon can be used on corn. Check the label for length of time re- 

 quired between application and harvest. Do not use toxaphene on forage to be fed to 

 dairy cattle or livestock fattening for slaughter. 



CORN 



Fall armyworms continue to damage late-maturing corn. These gray to dull-green to 

 dark-brown smooth- skinned worms feed deep in the whorl. Damaged leaves have a ragged 

 appearance. In some fields, fall armyworms are entering ears. Many of the worms are 

 now mature (1-1/2 inches) or soon will be. At maturity they stop feeding, drop to the 

 ground, and pupate in the soil. 



Control is difficult, especially with the larger worms that are deep in the whorl or 

 ear. For best results on whorl -stage corn, use granules of either carbaryl (Sevin) 

 or toxaphene at 1-1/2 pounds per acre. Sprays on whorl-stage corn provide erratic 

 results. If a spray is used, place the nozzles over the row and direct the spray into 

 the whorl. On tasselled corn, sprays should be directed at the ear zone and upper one- 

 third of the plant . 



■ 

 Do not feed toxaphene -treated corn as forage to dairy cattle. Do not feed toxaphene - 

 treated corn as silage to livestock fattening for slaughter. Corn treated with 

 toxaphene granules may be fed as stover to beef cattle to within 28 days of slaughter. 

 There are no restrictions for carbaryl . 



Rootworm beetles are abundant in some fields. If the corn is less than 50 percent 

 silked, an insecticide will help prevent pollination injury. Use carbaryl (Sevin), 

 diazinon, or malathion. Carbaryl is harmful to bees and although effective on 

 beetles, should not be used if bees are frequenting the tassels for pollen. In this 

 ';ase, use diazinon or malathion late in the day. 



