29 October 2016
After taking video of the foam coming from a beetle entry hole, the next step was to open it up and see what was producing the foam. Below are photos and a video. The video takes us from the surface to the beetle gallery. Note the white gel-like substance. That is probably the source of the gas in the bubbles. No beetle was found, but we may have touched a beetle elytra.
Please share your ideas on this.
29 October 2016.
We found a western oak bark beetle, Pseudopityophthorus pubipennis, in one of the cankers of the Cooper2 live oak branch. Cooper2 is an interior live oak infested with foamy bark canker. The beetle was small, about one and a half millimeters long. Sample collected 29 October 2016, by Paul Cooper.
29 October 2016.
Paul Cooper collected the branch on Cooper2, as seen at this page. The image of the branch is below, and the red circle indicates the area that the following video and photos were taken from. We were able to video, and photograph, the holes emitting foam.
The diameters of the holes are about 0.25-.33 millimeters. Each foamy spot is associated with one of these tiny beetle entry holes.
25 October 2016. Paul Cooper reports that he found another foamy bark canker infested live oak, in Greenhorn Creek, across the street from the Cooper1/golf course tree. This interior live oak tree does not appear to have cankers down at the base, but shows foamy attacks higher up, in the newer, and thinner, bark.
The tree is declining rapidly. This is more striking, being that Scott Oneto, Paul Cooper, Allan Ramorini and two of his lead men, and I, were at the “Cooper1 tree” about a month ago, and none of us noticed any decline in this second tree, that is just across the street. The fading of Cooper1 was obvious, but none of saw it. Now, it is readily apparent that this tree is fading fast, and that this fading took only about one month.
To support this claim, we again took the July 2012 Google Street View image, and the 2 April 2015 Bing Street View image, and placed them here to compare the tree over time. Again, the tree shows no decline in the previous years. To see this tree, as well as Cooper1 (across the street), use this link.
Lab analysis has confirmed that the live oak near the golf course is a victim of foamy bark canker. I found some older images of this same tree using Google and Bing Street Views. The Bing photo is the most recent, dating from 2 April 2015, and was taken when the sun was behind the tree, putting the bole in shade, making resolution difficult. But the tree is clearly in excellent shape. It appears to have grown well since the 2012 Google image was taken.
In September 2016, the oak was half dead. That means that in less than 18 months, the tree went from healthy and vigorous, to severely infected and dying.
Friday, October 21, 2016
New oak disease spreads from coast to foothills
By Alex MacLean, The Union Democrat
By Charity Maness, Calaveras Enterprise