Oak Wilt? Something Else?

[ATH]

pheromone may be the wrong word....was thinking an odor or attractant such as emitted by ash in China that resists EAB. This is probably just the odor of photosynthate that attracts the beetles. The same with elm I guess.

Trees release "volatiles" that some insects are able to detect telling them the tree is injured. That is a very generic term because insect pheromones are also volatiles...but they are released by insects. Same idea, a volatile organic compound (VOC: Like the stuff they try to limit in paint, etc....) that is triggered by a certain event to elicit a certain response. So, yeah same idea as pheromones...but released by a tree instead of an insect. You already knew that!

 

[treevet]

Trees release "volatiles" that some insects are able to detect telling them the tree is injured. That is a very generic term because insect pheromones are also volatiles...but they are released by insects. Same idea, a volatile organic compound (VOC: Like the stuff they try to limit in paint, etc....) that is triggered by a certain event to elicit a certain response. So, yeah same idea as pheromones...but released by a tree instead of an insect. You already knew that!

Wonder what the Chinese ash'es pheromone is that repels (instead of sugar enticing) EAB since it is likely injury induced or maybe it is just airborn. I know scientists have tried to recreate it crossing their ash trees with ours but I think their ashes are just an ugly/common looking tree and the beauty of ours is lost in the cultivar?

 

[ATH]

Wonder what the Chinese ash'es pheromone is that repels (instead of sugar enticing) EAB since it is likely injury induced or maybe it is just airborn. I know scientists have tried to recreate it crossing their ash trees with ours but I think their ashes are just an ugly/common looking tree and the beauty of ours is lost in the cultivar?

I think those are questions that are still being researched.... The Forest service Lab in Delaware Ohio is doing some of that research. They have a greenhouse full of ash saplings that they tape eggs to and somebody gets to peel all of those trees to count and measure larvae.

Last I knew, the working theory was not that Chinese ash repelled EAB, rather they didn't release whatever it is that EAB is able to "smell" so trees aren't as easy for the bug to find.

If that is so, it's a little crazy that a bug is adapted to find something in a tree that it isn't exposed to for several thousand years...