Plant and Insect Diagnostic Clinic Update - June 1, 2011

The following are highlights and updates about samples and questions recently received in the Plant & Insect Diagnostic Clinic:



Several calls and messages from far southern Iowa have been received about carpenter bees burrowing into rafters, deck joists and other bare, exposed wood.  Carpenter bee is a southern insect that has been reported as far north as Indianola in previous years, but this year appears to be present only in the southern half of the southern tier of counties.  Read last year's article in the Horticulture and Home Pest News for more detail.


We also got our first reports of four-lined plant bugs in central Iowa.  See below for a picture of the nymph.  These bugs make very characteristic small lesions all over the plant leaves they are feeding on. For more information please see this article




We’ve been getting quite a bit of conifer samples , especially Blue spruce. Most of the spruces are presenting Rhizosphaera Needle Cast, a disease caused by a fungus that makes the needles discolor and eventually drop. For more information on this disease, please visit our website.


The pines, specifically Austrian pines, have been diagnosed with Dothistroma Needle Blight and Diplodia Tip Blight. For more information on these diseases please see this article. 


We have also diagnosed many samples showing symptoms of environmental stress. Trees are presenting discolored branches, needle browning, and poor growth, which could be a consequence of poor drainage and possible root damage due to excessive water in the soil. It seems that trees are starting to show consequences of having several wet summers over the past couple of years.



Four-lined plant bug nymph.  Photo by Winston Beck.


Four-lined plant bug damage.  Photo by Winston Beck.


Links to this article are strongly encouraged, and this article may be republished without further permission if published as written and if credit is given to the author, Horticulture and Home Pest News, and Iowa State University Extension and Outreach. If this article is to be used in any other manner, permission from the author is required. This article was originally published on June 1, 2011. The information contained within may not be the most current and accurate depending on when it is accessed.