Plant and Insect Diagnostic Clinic Update - November 17, 2010

The following are highlights and updates about samples and questions recently received in the Clinic:


With the leaves mostly off the deciduous trees, we are receiving pretty much only conifer samples. Many samples have conifers with yellowing needles due to the water stress. Usually the needles are a very light tan in color. Blue spruces samples are coming in with Stigmina and Rhizosphaera needle cast disease.

Austrian pine with diplodia tip blight and dothistroma needle blight have been submitted. Similarly Austrian pine are no longer recommend for Iowa due to these diseases.

We also received a sample of Scots pine with pine wilt. Pine wilt is caused by a nematode. In order to diagnose pine wilt we chop up a sample of the trunk or lower limb, place the small pieces in a beaker of water. A day later we run the water through some sieves and look under the microscopes. There are plenty of nematodes, but we look only for the nematode that causes pine wilt, Bursaphelenchus xylophilus. The males can be ID’d by their T-shaped spiracle. The spiracle is sort of a clasping devise used in mating and trust me it is more T-like than other spiracles.


A few good freezes have put an end to the parade of fall accidental invaders, so we can rest easy until the multicolored Asian lady beetles wander out from the walls again in April. Right now a few stragglers are still hanging out around my sink where they come for water.

Through the winter we tend to get samples of carpet beetles – mainly the larvae – that are probably feeding on dead insects in the walls of the home and a variety of stored product pests such as Indian meal moths, red flour beetles, and cigarette beetles.

Questions about bed bugs and bed bug treatment alternatives continue to come in almost daily.  We recommend the following resources:

University of Kentucky Extension pamphlet ENT FACT 366, "Bed Bugs"

The National Center for Healthy Housing Bed Bug Report

When considering possibility of a bed bug infestation or household treatment, shop around for an experienced, professional pest control professional in your area.  Get at least 3 estimates and weigh the options carefully.  We do not consider bed bug treatment to be a do-it-yourself project.  Bed bugs hide in any and all tiny cracks and gaps in the bed, the bed frame and head board, nearby furniture, and behind wall outlet covers and baseboards.  The thoroughness required for effective treatment is generally beyond the do-it-yourselfer.


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