Looking inside a foaming canker
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.

After wiping away the foam, the hole is visible. The foam was very slow to come back, compared to what we saw in the earlier videos.

This is a picture of the back side, or underside, of the second slice, showing that white gel is there also.