92 ILLINOIS NATURAL HISTORY SURVEY CIRCULAR 47 



Control Measure 14. — Apply a lindane spray : 2 quarts of 20 

 per cent lindane emulsifiable concentrate to 100 gallons of water. 



Control Measure 15. — Apply an aldrin spray: 2 quarts of 25 

 per cent aldrin emulsifiable concentrate to 100 gallons of water. 



Control Measure 16. — Spray with aldrin, dieldrin, or hep- 

 tachlor: 1 pound of actual toxicant per 100 gallons of water. This 

 rate means 2 pounds of 50 per cent or 4 pounds of 25 per cent wet- 

 table powder per 100 gallons of water. 



Control Measure 17. — Inject diluted chlordane under and 

 around the root mass. For medium-sized plants, use about 1 gal- 

 lon of a mixture containing 1 gallon of 45 per cent chlordane 

 emulsifiable concentrate to 100 gallons of water. 



Control Measure 18. — Remove and burn all dead and dying 

 elm trees, limbs, and branches before European elm bark beetles 

 emerge in the spring. Also promptly remove and burn trees in- 

 fected with Dutch elm disease. Bark beetle feeding and the 

 spread of Dutch elm disease can be reduced by spray applications 

 of special DDT formulations, but the practical aspects and lim- 

 itations of such a spray program should be well understood be- 

 fore it is undertaken. Special information on Dutch elm dis- 

 ease and phloem necrosis is available from the Illinois Natural 

 History Survey, Natural Resources Building, Urbana, Illinois. 



Control Measure 19. — Apply a spray containing 2 pounds of 

 50 per cent carbaryl (Sevin) wettable powder per 100 gallons of 

 water. Small trees can be protected by a covering of cheesecloth 

 over each tree. 



Control Measure 20. — Gather up and burn infested twigs. 



Control Measure 21. — Apply a spray containing 2 pounds of 

 50 per cent carbaryl (Sevin) wettable powder per 100 gallons of 

 water. 



