Plant and Insect Diagnostic Clinic Update - July 26, 2013

The following are highlights and updates about samples and questions recently received in the Plant & Insect Diagnostic Clinic. Visit the PIDC’s Facebook page to ask questions and for updates and more pictures.




Strawberry root weevils are back!  These accidental invaders crawl into the house from the yard.  Read more at the Clinic website.  They are harmless and there is no need to use insectides, just sweep them up and discard (or kindly take them back outside).  They are usually only wander indoors for a short time each summer, so we should be nearing the end of the problem.




We are still getting samples and questions about conifers with needle browning and needle drop (many of them due to environmental stress). On the fruit and veggie side, we’ve received apple and crabapple samples with apple scab, Septoria leaf spot on tomato, bacterial spot and sunscald on pepper (photo below).


We have also seen two cases of impatiens downy mildew, Septoria leaf spot on Rudbeckia, and powdery mildew on zinnias and lilac.


It is the time of year when oak wilt symptoms are visible (browning of leaves on an entire branch and vascular discoloration). We have confirmed oak wilt on pin oak and bur oak already this year.  To test for oak wilt we need samples taken from symptomatic branches that are at least ½ inch in diameter. Ideal samples should be kept refrigerated and delivered to PIDC as soon as possible.  Please see our pamphlet on Oak Wilt for more information.



Strawberry root weevils resemble small ticks but have 6 legs and elbowed antennae.Strawberry root weevils resemble small ticks but have the three separate body parts, 6 legs and elbowed antennae.



Sunscald damage on green peppers. Photo credit: D. Mueller


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 July 26, 2013. The information contained within may not be the most current and accurate depending on when it is accessed.