Emerald ash borer treatment options and decision making
Laurie Stepanek, Forest Health, Nebraska Forest Service
Author
04/10/2017
Added
155
Plays
Description
Insecticide options have greatly expanded during the past decade. There are a wide range of chemicals and delivery systems available to homeowners, tree care companies and community forestry departments to help manage this insect. This session will cover the various options available and how to decide what is the best approach for different situations.
Searchable Transcript
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- [00:00:00.622]So, with that, Laurie Stepanek is with our
- [00:00:03.364]Forest Health Department.
- [00:00:05.117]She's been doing some fantastic handouts,
- [00:00:09.033]we've got a lot of those up at the handout table here.
- [00:00:12.695]We've been seeing those spread far and wide,
- [00:00:14.402]well outside of our state, even.
- [00:00:16.125]So, Laurie's going to discuss treatment options
- [00:00:18.992]for us today.
- [00:00:20.039]Thanks, Laurie.
- [00:00:22.046]Thank you, Graham.
- [00:00:22.947](applauding)
- [00:00:25.187]And so Graham mentioned the brochures
- [00:00:28.369]and so a lot of what I'm going to talk about
- [00:00:31.091]is actually contained in two brochures.
- [00:00:34.813]One is Trunk Injection Treatment Options for Professionals
- [00:00:39.137]and the other is
- [00:00:40.604]Selecting Trees for Emerald Ash Bore Treatments.
- [00:00:45.039]So, you can review the information
- [00:00:47.831]in those two brochures.
- [00:00:51.040]Let me make sure I know how to do this.
- [00:00:54.284]Okay, it wasn't that.
- [00:00:57.043]There we go.
- [00:00:58.343]Okay, so we've actually kind of heard a lot
- [00:01:00.973]from the last three speakers that
- [00:01:04.974]you need to have kind of a readiness plan.
- [00:01:09.583]So, we've kind of touched on some of these
- [00:01:10.976]different topics to include in a plan.
- [00:01:14.296]You need your inventory of your trees,
- [00:01:17.529]you may want to start removing some of your poor trees now,
- [00:01:20.810]and to be checking for Emerald Ash Bore.
- [00:01:26.109]Managing and utilizing the woody debris.
- [00:01:29.121]What are you going to do with all this material.
- [00:01:31.299]That needs to be thought about.
- [00:01:33.749]Planting a diversity of trees is part of it.
- [00:01:36.912]And then, in many communities, treatments are going to be
- [00:01:41.159]perhaps part of that plan as well.
- [00:01:43.583]If you have some high-value trees that you want to maintain
- [00:01:47.693]in your landscape for long-term purposes,
- [00:01:50.450]you may want to do some treatments.
- [00:01:52.685]And then treatments may also be important
- [00:01:54.966]in spacing out removals
- [00:01:57.574]so that you're not just
- [00:01:59.646]inundated totally with dead trees.
- [00:02:06.717]There's basically three different types
- [00:02:09.932]of treatment options:
- [00:02:11.722]there's your soil treatments,
- [00:02:14.334]there are systemic bark sprays,
- [00:02:16.871]and there are trunk injections.
- [00:02:19.837]And I'm going to just briefly talk about the first two.
- [00:02:22.920]I think trunk injections are going to be the main way
- [00:02:26.113]that professionals will have to treat trees.
- [00:02:30.832]So I'll spend a little more time on the trunk injections.
- [00:02:35.824]Just quickly on soil applications,
- [00:02:38.476]basically what the soil applications are
- [00:02:41.112]is applying a chemical to the soil
- [00:02:43.928]around the base of the tree,
- [00:02:45.861]and there's typically a lot of absorbing roots
- [00:02:48.756]right near the trunk.
- [00:02:51.039]So, the applications are done actually
- [00:02:53.599]quite close to the trunk of the tree
- [00:02:55.985]and the root system then picks up that chemical
- [00:02:58.940]and carries it up to the top of the tree
- [00:03:02.243]throughout the canopy.
- [00:03:04.368]And there's a couple of different
- [00:03:05.917]active ingredients involved,
- [00:03:07.559]the imidacloprid and the dinotefuran
- [00:03:10.420]are the systemic chemicals that are found
- [00:03:13.417]in these soil applications.
- [00:03:16.946]This is the primary method that homeowners
- [00:03:19.877]have available to them
- [00:03:21.637]are the soil applications.
- [00:03:22.903]And there's many different products out there
- [00:03:25.033]in the retail stores
- [00:03:27.820]and we typically tell homeowners if they are treating
- [00:03:34.170]to limit themselves to smaller trees,
- [00:03:36.336]generally maybe a maximum of about
- [00:03:38.489]15 inches in diameter
- [00:03:40.747]because these tend to not be quite as effective
- [00:03:43.447]in the larger trees.
- [00:03:45.136]If they have larger trees, we really encourage them to go
- [00:03:47.951]with professional arborist applications.
- [00:03:52.272]And then, of course, the professionals also
- [00:03:53.933]have options for soil applications as well.
- [00:03:58.437]Now, soil applications are typically done
- [00:04:01.616]once per year,
- [00:04:03.453]applied basically in the Spring.
- [00:04:06.213]If the active ingredient is imidacloprid,
- [00:04:09.391]that application would be done in April.
- [00:04:12.056]This is not as soluble a chemical
- [00:04:14.911]as the dinotefuran.
- [00:04:16.885]So the dinotefuran can be applied a little later
- [00:04:18.958]because it's able to be picked up
- [00:04:21.081]more quickly by the tree.
- [00:04:23.716]But they do take a few weeks to get up into the tree
- [00:04:27.009]and be distributed throughout the crown.
- [00:04:31.958]Some of the drawbacks with the soil applications
- [00:04:34.359]would be the uneven distribution
- [00:04:36.267]in some of the larger trees.
- [00:04:38.521]So, like I mentioned before, we like to encourage
- [00:04:41.696]people with larger trees to go with a different option
- [00:04:45.766]rather than soil applications.
- [00:04:48.040]And then, of course, the exposure to the environment.
- [00:04:50.855]These chemicals, dinotefuran and imidacloprid,
- [00:04:53.781]are both very toxic to honeybees
- [00:04:59.107]and so if you have, for example,
- [00:05:02.676]flowering plants below the Ash trees,
- [00:05:07.127]those plants are going to pick up this chemical as well
- [00:05:09.796]and carry that chemical into the pollen or the nectar
- [00:05:13.417]and potentially expose pollinators visiting those flowers.
- [00:05:18.078]So this would be an example where you would probably
- [00:05:21.485]want to go with the trunk injection
- [00:05:23.050]instead of the soil treatment.
- [00:05:25.834]These chemicals are also very toxic to aquatic organisms.
- [00:05:32.315]So you need to be careful about applying these
- [00:05:36.162]close to lakes or streams or if you have water levels
- [00:05:44.137]very close to the surface of the soil.
- [00:05:47.713]That would be another reason maybe not to be applying
- [00:05:50.069]these chemicals in these locations.
- [00:05:53.830]And then there's also,
- [00:05:55.145]and I think this was touched on a little bit earlier,
- [00:05:58.969]the possibility of over-application.
- [00:06:01.666]Because there are
- [00:06:05.679]per area limits to
- [00:06:08.322]how much of these chemicals can be applied per year
- [00:06:12.616]and these chemicals are also used in grub control.
- [00:06:17.505]So, when you're applying for grub control,
- [00:06:21.630]you potentially may already have reached
- [00:06:23.739]that maximum limit with that grub control application.
- [00:06:29.633]And this is just a real complex issue
- [00:06:31.680]because if you've got a lawn care company
- [00:06:34.626]doing your grub control,
- [00:06:36.412]and you've got your tree guys over here doing the trees,
- [00:06:38.097]nobody's talking to each other,
- [00:06:40.570]you may not know whether you're hitting that maximum amount.
- [00:06:47.589]So, just some considerations with soil treatments
- [00:06:51.019]to think about.
- [00:06:53.941]Systemic bark sprays, this is a chemical,
- [00:06:58.621]the active ingredient dinotefuran again,
- [00:07:01.211]and you're actually applying this chemical
- [00:07:03.670]to about the lower five or six feet of the trunk.
- [00:07:08.621]And it's actually absorbed through
- [00:07:11.786]the thin areas of bark on the trunk
- [00:07:14.796]between the ridges.
- [00:07:18.097]And then it's translocated up to the top of the tree.
- [00:07:22.369]And so this is available to professionals.
- [00:07:27.100]It has been shown to work pretty well
- [00:07:29.346]with trees up to about 22 inches in diameter.
- [00:07:32.961]So you can treat somewhat larger trees with it.
- [00:07:37.515]It's easy to apply, so that's a draw to that one.
- [00:07:43.682]But you do have the concerns
- [00:07:45.069]with the environmental exposure and the possibility
- [00:07:49.211]of non-target organisms contacting this chemical.
- [00:07:53.344]And you then also have those
- [00:07:56.505]per-area limits with this chemical.
- [00:08:00.497]And that's about all I'm really going to say
- [00:08:01.845]about those two types of treatment options.
- [00:08:05.337]I do want to talk about the trunk injections
- [00:08:07.668]a little more in-depth.
- [00:08:09.156]They're being very commonly used
- [00:08:12.719]by professionals.
- [00:08:15.502]There are several different chemicals
- [00:08:19.488]and several different methods for applying them.
- [00:08:24.314]Here's just kind of a quick overview
- [00:08:26.760]of some of the more common types
- [00:08:29.405]of methods that are out there.
- [00:08:32.035]A lot of them require that you actually
- [00:08:35.049]drill holes into the trunk
- [00:08:37.187]and then you have a pressure injection
- [00:08:39.174]of the chemical into the trunk.
- [00:08:41.171]And then that chemical is systemically moved up
- [00:08:43.746]then to the top of the tree.
- [00:08:49.832]The greatest advantage to the trunk injections,
- [00:08:54.257]of course, is that you are putting that chemical
- [00:08:58.226]right into the tree.
- [00:09:00.042]So only whatever's feeding on that tree
- [00:09:02.264]is likely to come in contact with that chemical.
- [00:09:05.399]So you've got less impact on your non-target organisms.
- [00:09:10.042]And you can treat larger trees, generally,
- [00:09:13.354]more successfully with the trunk injections.
- [00:09:17.839]Now, these do require some skill in applying.
- [00:09:22.059]You're drilling holes in trees,
- [00:09:23.966]you're injecting into areas where you've got to
- [00:09:27.468]make sure you've got good healthy tissue.
- [00:09:30.927]So, we discourage homeowners from doing this.
- [00:09:34.508]We really want to have the professionals
- [00:09:36.611]who have some skill with this doing these trunk injunctions.
- [00:09:41.935]And, of course, the big drawback is the fact that
- [00:09:45.867]these do cause damage to the tree.
- [00:09:51.085]And, in fact, the damage comes from
- [00:09:53.446]a couple different aspects of trunk injections.
- [00:09:57.395]The holes themselves that you drill into the tree
- [00:10:00.716]are causing damage,
- [00:10:02.721]and then the chemical, the actual chemical that's injected,
- [00:10:06.959]can also be toxic to the tissues.
- [00:10:11.303]Generally, the larger the holes, the more damage you have.
- [00:10:14.962]Generally, the more chemical that's injected,
- [00:10:18.422]again, the more damage that you have.
- [00:10:21.646]And a lot of this damage is occurring internally.
- [00:10:26.130]So a lot of people don't really realize what's going on
- [00:10:29.221]internally in the tree.
- [00:10:31.270]I'm just going to show some quick pictures
- [00:10:33.435]of injections that have been done.
- [00:10:36.807]What you see here,
- [00:10:38.480]do I have a pointer on here?
- [00:10:40.119]You can see the actual holes that were done here.
- [00:10:45.647]Here you just see kind of the shadow
- [00:10:47.506]of where the chemical caused damage to the interior
- [00:10:51.876]part of the tree.
- [00:10:54.403]And a lot of folks will ask me,
- [00:10:55.746]"Well, can you re-inject into the same holes?"
- [00:10:59.909]No, you cannot.
- [00:11:02.527]Each time you do an injection you have to move
- [00:11:05.264]that injection over to a different location.
- [00:11:07.898]So you start to get accumulated damage, internally,
- [00:11:11.849]as you continue to do injections over the years.
- [00:11:16.387]And, of course, you also have damage occurring
- [00:11:19.696]above and below the injection site as well.
- [00:11:24.364]This is important to note because the trunk area
- [00:11:28.577]is the area where the tree carries materials up,
- [00:11:36.730]the water gets moved up in the trunk area,
- [00:11:38.789]but this is also an area where sugar
- [00:11:43.387]that the leaves manufacture,
- [00:11:45.641]where the sugar is stored in the trunk
- [00:11:47.921]and sugar is the energy source for trees.
- [00:11:51.637]So, as you're causing this internal damage
- [00:11:53.597]you're taking away that energy storage location
- [00:11:58.457]for that tree.
- [00:12:00.991]So those are things to think about with injections.
- [00:12:03.787]I'm going to just do a little quick
- [00:12:06.113]tree anatomy lesson here.
- [00:12:08.762]I think most of you here know that,
- [00:12:11.265]as a trunk is growing bigger,
- [00:12:13.699]it's putting on new annual rings each year.
- [00:12:22.071]And so this outer ring here
- [00:12:24.178]is the most recent ring in a tree.
- [00:12:28.330]So, in this picture here, we have,
- [00:12:30.841]here's your bark,
- [00:12:31.990]this is an Ash tree,
- [00:12:34.084]and so this ring here is your outermost, newest ring.
- [00:12:40.316]A couple things that I'm going to show here is,
- [00:12:43.820]in Ash, most of the water is moved up
- [00:12:48.749]in that outermost one ring.
- [00:12:52.365]About 90 percent of the water moves up
- [00:12:56.274]in that outermost ring.
- [00:12:59.183]And then practically all of the water
- [00:13:01.049]is moving up in the outermost three rings.
- [00:13:03.726]So that's kind of your target location
- [00:13:06.108]for injecting pesticides
- [00:13:08.821]because the pesticides have to move up
- [00:13:10.667]in that water stream as well.
- [00:13:14.304]The other thing I want to point out in this picture
- [00:13:16.414]is notice how narrow the rings are.
- [00:13:20.654]This is a tree that was growing in an un-watered landscape.
- [00:13:26.214]It's growing very slowly,
- [00:13:27.975]it is stressed,
- [00:13:30.487]and so when the injections are done,
- [00:13:33.813]if they're done deep into the tree,
- [00:13:39.407]these rings in here are not going to
- [00:13:41.135]move the chemical up the tree.
- [00:13:43.897]The chemical that gets injected into this area
- [00:13:46.508]is going to just be injected into that area
- [00:13:49.395]and it's going to sit there and stay there.
- [00:13:51.482]And it'll just be wasted basically.
- [00:13:54.732]So, if you have a tree that's being cared for properly,
- [00:13:59.941]if it's being watered, if it's being mulched,
- [00:14:03.532]it's going to be growing bigger, better,
- [00:14:06.125]and have wider annual rings.
- [00:14:08.947]So you will have wider first rings that will then
- [00:14:12.644]be able to better take up that chemical
- [00:14:15.534]that gets injected.
- [00:14:18.347]I'm just going to show you that
- [00:14:21.787]each of the injection methods that are out there
- [00:14:24.751]have specific directions as to how deep
- [00:14:28.855]those injections need to be placed in the tree.
- [00:14:34.464]This is going to show you the size of the injection holes
- [00:14:37.631]that the various treatment methods
- [00:14:43.686]recommend for injections.
- [00:14:46.499]And so you see a lot of injections, if you have
- [00:14:49.396]a stressed, slow-growing tree,
- [00:14:51.914]a lot of injections are placing that chemical
- [00:14:55.355]into rings that do not move the material.
- [00:15:00.757]The point I'm trying to make here is
- [00:15:03.872]you want your trees that you want to keep long-term,
- [00:15:08.171]and I'm not talking the spacing removals,
- [00:15:14.614]I'm talking long-term trees in the landscape,
- [00:15:17.402]you want to choose good healthy trees
- [00:15:21.133]because they're going to respond better
- [00:15:22.845]to those treatments,
- [00:15:24.102]and they're going to better be able to handle the damage
- [00:15:27.855]that the injections cause.
- [00:15:33.628]I like to encourage folks to look at the history
- [00:15:37.971]of the care that the trees are receiving
- [00:15:40.541]that they're thinking about treating.
- [00:15:42.447]If they're getting the watering,
- [00:15:44.526]if they're getting a nice organic mulch around the base,
- [00:15:47.089]and I understand that a lot of city trees
- [00:15:50.295]don't get this.
- [00:15:52.873]A lot of city trees are totally on their own.
- [00:15:55.983]So you want to think about that if you're thinking about
- [00:16:00.454]treating trees in the city landscape.
- [00:16:02.790]If you have high-value trees in the city landscape,
- [00:16:06.684]see if you can't start doing some of these things
- [00:16:09.233]to make them be better candidates for injections.
- [00:16:18.005]Just to show some pictures.
- [00:16:19.745]Poor candidates for treatments.
- [00:16:21.031]And I think this will be very obvious to most of you.
- [00:16:24.596]Look for specific things that tell you
- [00:16:27.027]this is not a good candidate for treatment.
- [00:16:29.927]If you've got mushrooms and conks in the tree.
- [00:16:32.437]If you've got other borer activity going on in the tree.
- [00:16:36.658]Trees that are stressed attract borers.
- [00:16:39.519]And so our native borers get into the trees
- [00:16:43.105]so that would indicate you've got a stressed tree
- [00:16:44.823]that wouldn't respond very well to the treatments.
- [00:16:48.123]Look for mower injury at the base of the tree.
- [00:16:52.013]This is where you're supposed to do those injections.
- [00:16:55.287]If you've got injury like this down there
- [00:16:56.923]you're going to have trouble getting good uptake
- [00:16:59.281]of that injected chemical.
- [00:17:04.069]Girdling roots,
- [00:17:07.120]roots wrapping around the base of the tree,
- [00:17:09.370]could actually be slowing down the ability of that tree
- [00:17:12.033]to pick up water.
- [00:17:15.402]A lot of trees have been planted deep.
- [00:17:17.535]Many of you know this.
- [00:17:19.517]If you have no root flare down here.
- [00:17:22.147]This tree shows a little root flare right here,
- [00:17:24.868]how the trunk moves out into the roots and stuff.
- [00:17:27.594]This tree goes straight down into the ground
- [00:17:29.510]sort of like a telephone pole,
- [00:17:31.557]suggesting that that tree is too deep in the soil
- [00:17:34.835]which is a very stressful situation for trees.
- [00:17:38.302]So not a good candidate for treatment.
- [00:17:40.806]So, just look at your trees and see.
- [00:17:42.600]Do they have these characteristics?
- [00:17:46.569]Epicormic shoots.
- [00:17:48.449]A lot of our trees,
- [00:17:49.800]and Kathleen talked about this in Colorado,
- [00:17:53.691]the trees look bad, they just really look bad,
- [00:17:56.582]because we've got such stressful conditions.
- [00:18:00.434]So water sprouts, suckers, epicormic shoots,
- [00:18:02.164]whatever you call them.
- [00:18:03.691]These very small diameter branches coming out
- [00:18:06.805]on the main shoots.
- [00:18:09.174]They're an indication that you've got a stressed tree.
- [00:18:14.301]Thin canopy.
- [00:18:15.485]Branch dieback.
- [00:18:16.443]Anything that indicates a stressed tree.
- [00:18:20.102]Not a good candidate for treatment.
- [00:18:22.003]And looking at the structure of the trunk,
- [00:18:25.625]the major branches,
- [00:18:27.547]if you've got a lot of branches coming out
- [00:18:31.028]from one point,
- [00:18:33.058]if you've got included bark,
- [00:18:35.593]you notice how these two main trunks are at
- [00:18:39.047]a very, very narrow angle
- [00:18:41.640]and, as they've grown, they've pinched the bark
- [00:18:44.981]in between them.
- [00:18:46.999]That's not a very strong union.
- [00:18:49.442]So there's the potential for or the other
- [00:18:51.596]of those trunks to split out.
- [00:18:53.659]So these are trees that really should be removed.
- [00:18:57.066]And I know many of you know this and recognize this
- [00:19:00.166]as these are not good trees for the landscape.
- [00:19:05.202]And looks can be deceiving.
- [00:19:07.399]Here's a tree that really looks pretty good,
- [00:19:09.500]a nice Ash tree.
- [00:19:11.185]But a close look, take a look at that branch structure.
- [00:19:16.851]So take a close look at these trees.
- [00:19:18.409]Don't just assume a nice looking tree like that
- [00:19:20.732]is going to be a good candidate for treatments.
- [00:19:26.633]I'm going to keep moving here
- [00:19:28.619]because I've got a little bit more.
- [00:19:30.452]And then location issues, of course,
- [00:19:32.336]are always going to come into play,
- [00:19:35.194]with whether you decide or not, to treat.
- [00:19:40.892]The point is, let's be selective about any trees
- [00:19:43.574]that we want to maintain long term.
- [00:19:49.300]Back to trunk injections real quick.
- [00:19:50.870]A couple more points.
- [00:19:53.061]Better to apply mid-May to early June.
- [00:19:55.745]What you're trying to do is get that chemical into the tree
- [00:20:00.132]at the time that the adults are coming out
- [00:20:02.179]and starting to feed.
- [00:20:03.312]So the adults are starting to feed on the leaves,
- [00:20:07.020]they come out about mid-May,
- [00:20:08.950]and if you can get that chemical in there you're going to
- [00:20:11.810]control the adults,
- [00:20:13.112]they won't be laying eggs,
- [00:20:14.671]there won't be as many larvae.
- [00:20:16.898]So that's really kind of the optimal time for treatments.
- [00:20:21.453]The effectiveness kind of drops as you go
- [00:20:23.289]later, later into the season.
- [00:20:26.548]And then, heat or drought-stressed trees
- [00:20:31.042]tend to get more injury if they're treated
- [00:20:35.801]late in the season.
- [00:20:37.300]So when we're in July and August
- [00:20:39.843]and we're hitting 95 degrees,
- [00:20:42.491]there's the potential for that concentrated chemical
- [00:20:45.462]that you inject to cause more damage.
- [00:20:50.635]Timing of once per year if you're using imidacloprid
- [00:20:55.467]for the injection chemical.
- [00:20:57.395]Once for two years is what is being used
- [00:20:59.929]for emamectin benzoate and azadirachtin.
- [00:21:03.865]And for a homeowner hiring a professional
- [00:21:08.538]we've been giving an approximate amount of about
- [00:21:11.834]a hundred dollars per year for a 20 inch diameter tree
- [00:21:17.824]as the cost.
- [00:21:18.878]And that would be for what a homeowner would pay
- [00:21:21.547]a professional, on average.
- [00:21:27.100]And then just real quick,
- [00:21:28.236]so we've talked a little bit,
- [00:21:29.541]how close should Emerald Ash Bore be
- [00:21:33.072]before you start your treatments.
- [00:21:36.936]In Nebraska, we're using a 15 mile treatment
- [00:21:40.549]consideration zone so that
- [00:21:43.301]if your tree is within 15 miles of a known infestation
- [00:21:48.883]that would be a time to think about treatments.
- [00:21:53.110]So we've got the Greenwood, Nebraska infestation down here,
- [00:21:58.798]a couple of the known infestations in Omaha.
- [00:22:04.559]We're not worrying too much about
- [00:22:06.281]finding more infestations in Omaha.
- [00:22:08.984]Once it's been found in a county,
- [00:22:11.845]we're kind of going with the idea that,
- [00:22:13.716]okay, yeah, it's in Omaha.
- [00:22:19.035]And then Missouri Valley, Iowa also has an infestation
- [00:22:21.785]which works its way,
- [00:22:23.561]the 15 mile zone moves into Nebraska a little bit there.
- [00:22:28.862]So that's where we're recommending treatments to begin,
- [00:22:35.079]I know that there's a lot of people that are
- [00:22:38.319]very, very concerned and they're anxious
- [00:22:39.530]to start treatments if they're outside of this zone
- [00:22:43.521]but we've kind of talked about this
- [00:22:44.628]already this morning.
- [00:22:46.383]We don't know when it's going to show up
- [00:22:48.351]in your area.
- [00:22:49.296]It could be many, many years before it shows up.
- [00:22:54.660]With treatments in general, it's always kind of
- [00:22:56.141]a balancing situation.
- [00:22:59.702]The need to treat and protect trees
- [00:23:03.005]versus the drawbacks to treatments.
- [00:23:06.229]So, where is that balance point.
- [00:23:08.516]And we think that that 15 miles zone
- [00:23:10.266]is a good balance point.
- [00:23:13.874]I try to tell people to kind of keep in mind
- [00:23:16.511]that Emerald Ash Bore is attracted to stressed trees,
- [00:23:22.690]like any borers are.
- [00:23:25.572]They just happen to also be very good
- [00:23:27.309]at killing healthy trees.
- [00:23:29.212]But they're going to tend to go after
- [00:23:30.706]a stressed tree first if they have that preference.
- [00:23:34.613]So, if you have a valuable tree
- [00:23:37.504]and you are caring for it,
- [00:23:39.402]you're watering it, you're mulching it,
- [00:23:40.718]you're doing the things that will keep that tree healthy,
- [00:23:44.969]your tree will not be the first one
- [00:23:48.022]that Emerald Ash Bore's going to go after.
- [00:23:50.372]It's very unlikely that if you're outside
- [00:23:52.755]that 15 mile zone,
- [00:23:54.523]that Emerald Ash Bore's going to go for your tree first.
- [00:24:00.043]So that's kind of how we justify the 15 mile zone.
- [00:24:04.054]And I also, as has been mentioned before,
- [00:24:07.301]infested trees can be treated successfully.
- [00:24:10.624]So even if your tree does happen to be infested,
- [00:24:14.187]still looks good,
- [00:24:15.826]doesn't have a lot of thinning in it yet,
- [00:24:17.259]it still can be treated quite successfully.
- [00:24:26.113]Biological control has been talked about
- [00:24:28.197]already a little bit.
- [00:24:29.449]Yes, there are some parasitic wasps
- [00:24:31.951]that will actually go after the larvae
- [00:24:35.648]or the eggs of Emerald Ash Bore.
- [00:24:40.125]This is not going to save anybody's tree.
- [00:24:44.678]This is probably going to come into play
- [00:24:48.190]say after most of the Ash trees are gone
- [00:24:51.497]and these will help to control the population
- [00:24:56.178]of Emerald Ash Bore that is left
- [00:24:58.847]and maybe will help in concert with treatments
- [00:25:03.814]so you don't have to be treating as often as you would.
- [00:25:08.392]So, they'll play a role but they're not going to
- [00:25:12.121]save anybody's tree.
- [00:25:15.801]I think that's about all I have.
- [00:25:17.831]I'm kind of going quickly because I know lunch is here.
- [00:25:23.812]Like Graham said, we've got a whole afternoon
- [00:25:25.890]of talking about injections
- [00:25:28.521]so we can take questions at that time
- [00:25:31.554]and I'll be here all afternoon too.
- [00:25:34.322]So, thank you, everyone.
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- Tags:
- Forest
- Ash
- Emerald Ash Borer
- Trees
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