May 7, 2008

Plant and Insect Diagnostic Clinic Update - May 7, 2008

Plant Problems

Training and Trellising Raspberries

Raspberry plants are relatively easy to grow. They are also hardy and productive in most parts of Iowa. If given good care, a 100-foot-long row of red raspberries can produce 100 to 150 pints of fruit. Proper training and trellising of raspberry plants help insure a good fruit crop.

Watch Now for Tents on Trees

Now is the time when we should notice the silvery-gray webs of the eastern tent caterpillar on apples, crabapples, wild plum, cherry and related trees. Caterpillars emerge in late April and early May from eggs that were laid on small twigs last summer by the female moths. The caterpillars gather at a major branch fork or crotch and begin to build the silk tent.

Watch This Month for Scale Insect Crawlers

Scale insects are sap-feeding pests that derive their name from the scale or shell-like waxy covering over the insect's body. The protective covering makes scale insects difficult to control through most of their life. Therefore, great emphasis is placed on understanding the life cycle and applying controls at the time the eggs are hatching and the pest is vulnerable to insecticides. The new scale nymphs are called "crawlers" because they crawl about on the plant before settling at a new feeding site.