Plant and Insect Diagnostic Clinic Update - November 11, 2016

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 to ask questions and for updates and more pictures. For more information on a particular disease or insect problem listed, follow the article cited.


Perennials and Annuals
Botyrophaeria canker on cotoneaster - Cankers and Diebacks

Rose rosette- Rose Rosette

Bark beetles, poplar and ash - Bark Beetles in Trees and Firewood

Conifer trees

Diplodia tip blight on Pine and Austrian Pine - Diplodia Tip Blight and Canker

Seasonal needle loss on pine and other conifers - Seasonal Needle Loss

Stigmina needle cast on spruce - Stigmina

Mushroom Identification

White rot associated mushroom.  White rot fungi are common parasites of heartwood in living trees and are aggressive decomposers of woody debris in forest ecosystems.  This type of specimens are rarely found in household wood.


In households, wood decay fungi can colonize wood that is exposed to high moisture levels. Once established in the wood, there is no cure or treatment that is proven to eradicate it. Reducing moisture levels (repairing any leaks) can reduce the growth of the fungi, but the best management will also be to remove and replace any water-damaged and decaying wood.


Household insect pests

Wolf spider - wolf spider information

Wood cockroach - wood cockroaches

Humpbacked (Phorid) flies - information from the University of Minnesota

Fruit flies - Fruit, Vinegar, and Pomace Flies


Bark beetles on white pine - primarily chestnut-brown bark beetles (Pityogenes sp.) have been observed.  They will attack trees in decline.

Bark beetles on ash - Common Problems of Ash Trees

Spider mite damage on Arbovitae - Spider Mites



Lina Rodriguez Salamanca Extension Plant Pathologist and Diagnostician

Dr. Lina Rodriguez-Salamanca is a diagnostician and extension plant pathologist with the Iowa State University Plant and Insect Diagnostic Clinic  (, a member of the National Plant Diagnostic Network (NPDN, ...

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 November 11, 2016. The information contained within may not be the most current and accurate depending on when it is accessed.