HOMEOWNER PEST PROBLEMS 



Trees and Shrubs 



Oystershell scale eggs began hatching this week in central sections. It will be 

 another 2 weeks before hatch is complete, and during this time the newly hatched 

 crawlers will be setting up housekeeping on shrubs, like lilac and dogwood. Wait 

 until hatch is complete before treating. Crawlers can be controlled by a careful 

 and thorough spraying with malathion (2 teaspoons of 50- to 57-percent concentrate 

 per gallon of water). Even though scales are killed by spraying, the scale cover- 

 ing will persist for several months. 



Hawthorn leaf miner egg hatch is complete in central sections. The maggots dis- 

 figure leaves and damage plants by eating the tissue between the upper and lower 

 surface of the leaves. Treat immediately with malathion (2 teaspoons of 50- to 

 57-percent emulsifiable concentrate per gallon of water) or diazinon (2 teaspoons 

 of 25-percent emulsifiable concentrate per gallon of water) . 



Pine needle scale eggs began hatching this week in central sections. Egg hatch 

 should be completed in one week. The crawlers feed in particular on white pine 

 and Norway spruce. For control, spray with malathion (2 teaspoons of 50- to 

 57-percent concentrate per gallon of water) . 



Juniper blight , caused by a fungus, became epidemic in Illinois in 1966 and 1967. 

 Although the disease has been reported from the Midwest since the late 19th Century, 

 and is widely distributed throughout the state, it seldom causes significant damage 

 unless weather conditions become favorable for disease development. The prolonged 

 wet, cool springs of the past two years have been nearly ideal for development and 

 spread of the disease. 



The most common symptom of juniper blight is the browning or blighting of young 

 shoot tips, which may appear in early May in southern Illinois and as late as 

 July 1 in the northern part of the state. At the base of the brown or blighted 

 tissues, very small, black fruiting bodies of the disease fungus may be seen under 

 a hand lens or microscope. Spores which are formed in these fruiting bodies are 

 released during wet weather and are easily spread at that time to other branches 

 and adjacent healthy plants by driving rains or on pruning or shearing tools. On 

 highly susceptible hosts, the fungus may invade and girdle larger stems, resulting 

 in browning and death of major branches. 



Since the fungus fruiting bodies persist through the winter on the blighted shoots, 

 a tremendous number of spores may be released this spring and, if weather conditions 

 are again favorable for disease development, another juniper blight epidemic could 

 occur in 1968. 



Several control measures, if used correctly, may be effective against juniper blight. 

 All blighted twig tips should be removed and burned to eliminate the sources of in- 

 fection. Pruning or shearing should be done on a dry day to reduce spread of the 

 fungus to other plants by contact. In addition, susceptible plants may be sprayed 

 at 7- to 10-day intervals from the time new growth begins in the spring through 

 early to mid- July. Organic mercury fungicides at the rate of 1 pound or 1 pint in 

 100 gallons of water will do a good job of control. Bordeaux mixture 8-8-100 or 

 copper fungicides at 3 to 4 pounds in 100 gallons of water are also effective. 



