Wood cockroaches, also known as wood roaches, are common outdoor dwelling insects native to North America and found throughout Iowa. Their normal habitat is moist woodland areas but they frequently become a household nuisance because they wander into or are carried into houses as "accidental invaders."
Cracks on the trunks of trees may be caused by environmental factors such wind, harsh winter conditions and mechanical injuries among others. Cracks become the entrance point for decay fungi. Fungi are well-known recyclers, as they possess the enzymatic machinery to degrade a wide variety of compounds present in the wood.
The following are highlights and updates about samples and questions recently received in the Plant and Insect Diagnostic Clinic. Visit the PIDC's Facebook page for updates and more pictures. For more information on a particular disease or insect problem listed, follow the article linked.
The following are highlights and updates about samples and questions recently received in the Plant and Insect Diagnostic Clinic. Visit the PIDC's Facebook page for updates and more pictures. For more information on a particular disease or insect problem listed, follow the article cited.
While marigolds are seldom bothered by insects and diseases, they are not problem free. Spider mites can devastate marigolds in hot, dry weather. Grasshoppers can also cause considerable damage. Aster yellows is an occasional disease problem. Aster yellows is caused by microorganisms called phytoplasmas. The disease is transmitted from plant to plant by sap-sucking insects, such as leafhoppers. Marigolds infected with aster yellows are stunted, yellow-green in color, and their flower buds fail to open. Infected plants should be dug up and destroyed.
Wood cockroaches, also known as wood roaches, are common outdoor-dwelling insects native to North America and found throughout Iowa. Their normal habitat is moist woodland areas but they frequently become a household nuisance because they wander into or are carried into houses as "accidental invaders."
Now is the time when homeowners will notice medium-sized cockroaches wandering about the house in the middle of the day. These are usually wood cockroaches, also known as wood roaches.
Wood roaches are similar in appearance to the household cockroaches, but they live exclusively outdoors. They live in rotted logs, tree stumps, hollow trees and under the loose bark of dead trees and firewood. They are especially noticed at this time when the males are active and attracted to lights.
Newly emerged perennial growth is susceptible to damage from freezing temperatures. While freezing temperatures may have damaged or destroyed the new growth, the roots and crowns of healthy, well-established perennials should still be alive. The damaged perennials should send up a second flush of growth in a few weeks. Good care (for example, watering weekly during dry weather) this spring and summer should help the perennials recover.
Fortunately, there is still time to plant several vegetable crops. In central Iowa, the last practical date to plant early maturing sweet corn varieties is July 1. Cucumbers and summer squash can be planted until July 20. August 1 is the last practical date to plant snap beans, carrots, and beets. (The last practical planting dates would be approximately 1 week earlier in northern Iowa and 1 week later in southern portions of the state.)
Pine wilt is a serious disease of pines, especially Scots pine, in the Midwest, including Iowa. Infected trees wilt and die within a matter of weeks to a few months. Although a nematode is the primary disease agent that blocks water flow in affected trees, pine sawyer beetles are the vectors that carry the nematodes from infected to helathy trees. The major recommendation to help control spread of the disease is to remove infected pines promptly and burn, chip, or bury them.
