June 16, 1993
'Large black ants' have become the most common topic of discussion for callers to the Extension Entomology office during the past week. Apparently, wet weather over the past year and a half has been favorable to the carpenter ants and their numbers have increased with a corresponding increase in the numbers of workers and swarmers invading homes. The following are answers to some of the most common questions.
Fire blight. Blossom blight and shoot blight have been reported in apple orchards in southwest and central Iowa during the past 2 weeks, but the incidence of these phases of fire blight appears to be low. We can be grateful for the cool prebloom and bloom period conditions, because they helped to suppress activity of the fire blight bacterium, which prefers average daily temperatures above 60o F. Because of the cool weather, the MARYBLYT program did not advise spraying during the bloom period in several orchards even when rain or heavy dew had occurred.
Not many of us can go into the lumberyard and pick up everything we will need to build a home or business without prior planning. Creating a landscape that fits our needs requires much the same thought and consideration. Who does a person go to when they are in need of landscaping?
Peony diseases have been a common problem this spring. Wet conditions have favored the development of several diseases.
Leaf blotch and stem spots. Leaf blotch is the most common disease of peony. The fungus Cladosporium paeoniae causes reddish- purple spots on leaves and stems. Often spots coalesce so that leaves appear irregularly blotched. On stems, infection appears as reddish-brown spots or streaks.