Micro-Organisms - native

Shothole disease (Wilsonomyces carpophilus) on Apr 2, 2012

Submitter does not have a specimen

Description of specimen

Emanating from the area of the Koi Pond (which has some exotic plants), there is a varacious leaf eating insect, eating laurel leafs, bamboo leafs, and anything else in the path.

Commentary

Chris, thanks so much for the report. I have notified our local ODA experts to investigate this immediately. Will let you know what we find. Thanks so much for the report!

Lisa DeBruyckere
April 2, 2012, 3:41 a.m.

Temperatures have been fairly cold this year, limiting insect activity. The symptoms I see in the photos you sent of the Prunus laurocerasus hedge could be symptoms of a plant disease common to the Prunus species (of which Laurel is a member), known as "shothole" disease. The disease is typically caused by the interaction of several types of bacteria and fungi which cause reddish to brownish colored diseased spots. These spots decay and drop off leaving holes that resemble damage from shotgun pellets. Shothole is exacerbated by rain and frequent overhead irrigation. Our very wet spring has contributes to this.

Here are some websites from OSU and UGA that describes shothole disease in laurels. There are non-pesticide and pesticide controls. However, based on your photos, the Laurels look healthy and vigorous. I think you will see the symptoms taper off when we get an extended period of dry weather. The laurels look relatively vigorous, even with the shotholes. Barring other factors, the laurels should recover this summer.

Pease don't hesitate to contact us if I can be of further assistance.

Prunus laurocerasus Prunus laurocerasus -- Leaf Spots and Shothole
http://plant-disease.ippc.orst.edu/ShowDisease.aspx?RecordID=930

http://ugaurbanag.com/content/shot-hole-disease

Effect of Fungicide Treatment to Control
Shot-Hole Disease of Cherry Laurel
http://www.canr.org/98013.pdf

UC Davis IPM site
http://www.ipm.ucdavis.edu/PMG/GARDEN/FRUIT/DISEASE/shothole.html

Lisa DeBruyckere
April 5, 2012, 1:49 a.m.