-2- 



The periodical cicada is due to emerge over a large area of Illinois this 

 year. There are two broods, which are one reason for the extensive area that is 

 involved. The 13-year brood will emerge in the area south of U. S. Route 36, while 

 the 17-year brood will confine itself to western Illinois. 



Emergence is just beginning in extreme southern Illinois and will continue 

 northward in succeeding weeks. The almost continuous high-pitched shrill sound made 

 by the males announces their presence. The females seek, out trees and lay eggs in 

 slits in small branches, which will turn brown and die. Damage is sometimes severe 

 in newly planted orchards or new plantings of shade trees. 



A relatively new but safe insecticide, Sevin, is an effective control. It 

 should be applied when cicadas become numerous and the application repeated in 7- 10 

 days if needed. Use 2 pounds of the 50$ wettable powder or 1 pound 3 ounces of Q% 

 spray able powder per 100 gallons of water. For smaller amounts, use 2 teaspoons per 

 gallon of water. Do not apply Sevin to producing apple trees within 30 days after 

 full bloom, since it may cause fruit thinning. Sevin may be used to within one day 

 of harvest on fruit trees. Do not apply it to Boston ivy. 



Fall cankerworms were observed damaging oak and elm trees this week. Some 

 trees were nearly completely defoliated. This worm is a close relative of the spring 

 cankerworm, and the habits, damage, and control of the two are similar. Cankerworms 

 attack a wide variety of shade trees as well as fruit trees. A spray of h pounds of 

 lead arsenate per 100 gallons of water will control these pests. 



Caution : Before applying insecticides, read the labels carefully and fol- 

 low all precautions. This will not only insure personal safety, but will also elimi- 

 nate insecticide residue hazards. 



This weekly report was prepared by H. B. Petty and Steve Moore, Illinois 

 Agricultural Extension Service and Illinois Natural History Survey, in cooperation 

 with the USDA Agricultural Service, Plant Pest Control Branch, from information 

 gathered by entomologists and cooperators who send in weekly reports from their own 

 localities. 



H3P:dl 

 5/17/63 



