Jonny,
That is a rediculous price for the treatment and should be more in the 4-6 per inch area. I would suggest re-quoting this with a less CORPORATE and more specialized tree service like American Arborists Tree Service or Farina Tree Care.

Thanks Matt! I am going to call them this week-- around $300-400 was what I had considered I would be able to pay for this so that is perfect...

jbw, there are several known predators on the beetle in China, which keep them in check and prevent all ashes there from being infested. Presumably, too, the native ash species in China have also developed some resistance, as they (and the predators) have all evolved together. This is the case with most exotic and invasive species, such as the zebra and quagga mussels, buckthorn and garlic mustard, even dandelions. Imported species with no natural predators spread unchecked through any suitable new habitat. There are clinical trials going on with tiny wasps imported from China that prey on emerald ash borers. But it isn't as easy as just breeding a few million wasps and letting them go. First you have to make sure that a.) they can survive in the same habitats here as the beetle does, and b.) (and more importantly) that they won't turn out to be a pest as bad or worse than the one they are meant to control. This has happened frequently. Good example: They imported sugar cane to Australia. Then, by accident, a cane beetle showed up that was ravaging in the cane crop. So they imported the cane toad to control the beetles. Which it did, to some extent. But it also took an even greater liking to every native Australian species it could swallow. And they're honking big toads. As you would expect of such a story, they couldn't find anything that would eat the toads, and now they can't get rid of them. We wouldn't want a plague of wasps, but they do give hope that ashes may survive.

Also, it may be that the wasps alone, without whatever natural resistance factors the native trees (of China) have adapted to the beetles, will not do the job. There are many instances in nature in which a plant that is attacked by a pest releases chemicals that attract the predator on that pest. Our native ashes may not have that capacity, or might lack some other critical system that co-evolution has given their Chinese cousins. To answer your other questions, it's probably too soon to know at this point whether the beetles, unchecked, would actually annihilate all ashes. The chestnut blight wiped out virtually every American chestnut tree. The Dutch elm disease left a lot of American elm survivors, and they reproduce, and their offspring grow to reproductive age with great regularity, filling my garden each year with hosts of elm seedlings. Right now, it's looking rather bad for the ashes, as they seem to be pretty thoroughly devastated where the infestations are worse. But as it spreads wider, we might see something different – a slowdown, some trees surviving, or ash seedlings coming back where the beetle has moved along. It could become more Dutch elm-like and less Chestnut blighty. And finally, I haven't heard that the emerald ash borer attacks any other trees where it's wiped ashes.