cedar trees have borer holes -

[Dr_dewey]

Hi: have several mature eastern cedars that are browning, they have small holes 1 mm diameter and there are some spots with dried sap running down the bark.

one tree was cut down last year, and i think the pests are spreading to these other tress, they are touching each other. this is a pic of some of the holes. The trees are in Toronto, Canada.

Any idea what the cause is? is there a treatment ? do you need more details.

thanx in advance

Ray in Toronto

 

[Sylvatica]

You do have borer holes, probably from bark beetles.

The bark shown doesn't look stringy enough or the right color for eastern red or white cedars. Are you certain it is? It certainly could be though, maybe it's just the pic w/o foliage throwing me off. That cut should have shown a red heartwood if red cedar. Even Atlantic white cedar has stringy-er bark.

Regardless, borers are often 'the symptom, not the problem' meaning they hit plants already stressed by precursors - drought, age, poor soil conditions, winter injury, etc.

Borers often vector in particularly nasty canker and root rot pathogens, and the substance exuded may be caused by such.

Often borers, looking like yours but different species, will affect standing or cut deadwood.

Without getting into spraying pesticides on the trunk during a known specific window of time, the best approach is one of prevention - mostly through stress avoidance.

 

[Guy Meilleur]

Bark looks nothing like Juniperus virginiana which is what we call eatern red cedars. More like pine. If you want to know what your problem is, rip the bark off the dead tree and find the bugs. If they are black/brown and size of rice grain then they are Dendroctonus bark beetles and they can indeed be the primary problem.
ID the tree and ID the pest. Then finding the right treatment will be easy.

 

[Sylvatica]

I agree with you, Guy.

Certainly could be pine bark and pine bark beetles.

How about some pics of tree and foliage, Dr Dewey?

 

[Dr_dewey]

more pics

we call them cedars here, thought it was eastern white cedar, no red center wood, not aromatic. here are some shots of the leaf and sap run

 

[Dr_dewey]

another pic of seed pods

 

[Guy Meilleur]

Re: more pics

Originally posted by Dr_dewey
we call them cedars here, thought it was eastern white cedar,

Yeah looks like Chamaecyparis thyoides, a swamp plant here that does ok elsewhere in moist sandy soil. the holes look like exit holes of bark beetles; can you peel off dead bark and photo the bugs inside?

 

[Dr_dewey]

peeled back the bark

these are from the tree cut down last year, it sat outside all year and hence has been through a lot of freeze-thaw. no sign of live bugs.

 

[Kneejerk Bombas]

I'd say he has the correct tree ID, Thuja occidentalis or Eastern White Cedar. Around here we call them Arborvitae.

I have not seen borers on these trees. I suspect the tree is under stress from something else, and the borers are secondary. This doesn't mean they shouldn't be treated, just that we need to figure out what is the original stressor.

Our company treats borers with Imidacloprid, sold as Merit. This would not normally be a homeowner treatment. A trip to the garden center could prove me wrong, Ortho sells a lot of chemicals. This is the time of year to apply Merit, as it is very slow to move into the tree. Product applied now will just start moving into the tree in spring.

In the picture, there appears to be some kind of construction going on in the background. Is there any change to the root zone of the trees? Could you post a picture of the ground around the base of the tree?

 

[Sylvatica]

I can now see that you do indeed have thuja occidentalis, Arborvitae. Mike is correct.

He is also right about Merit. In my state, imidacloprid can be bought OTC as Bayer Tree & Shrub Insect control.

The catch-22 with Merit and 'Arbs' is that its use often leads to an infestation of mites (won't kill the mites, but eliminates the predatory insects which eat the mites) so be careful using Merit on mite-prone plants.

Again, there is still another stressor affecting the trees.

 

[Dr_dewey]

stressors

The year 2002 was very dry here - no rain for 5 or 6 weeks in August and noticed the first cedar was browning then. 2003 has been normal or even wetter than normal so water is not a factor i would think.

there was no construction in 2002, in 2000 or 2001 a few posts were put in for a new fence, they are on 7 or 8 ' centers and maybe 3 or 4 ' from any tree trunk. the fence can be seen in a few of the pics.

the blue stuff in the background is the covered pool and water bags.

my other question is - will the borers attack the trees that are beside the damaged ones?? or if they have enough water and no stress they can fend for themselves.

i will look for merit and if its not available then get a pro in to do it or at least have them check the situation.

thank you for all the advice.

 

[Kneejerk Bombas]

Re: stressors

Originally posted by Dr_dewey
my other question is - will the borers attack the trees that are beside the damaged ones?? or if they have enough water and no stress they can fend for themselves.

I would guess that the other trees are at increased risk of borer attack because they had or have the same stress, and the borers are close by.

I would treat the whole row of trees this year with Merit, it won't cost too much more to do a row as opposed to doing a single tree. Then, work on the soil around the trees to improve it. Most garden centers sell composted cow manure in 40 pound bags for about $2 US, so that's about what, $3,000 Canadian? Anyway, spread a couple bags around under the dripline of each tree and then add a thin layer of wood chips on top of that. Make sure the added layer does not get deeper than 3" total, and keep it off the trunks.

The wood chips and compost can be replenished each year to keep it looking good and they will help keep the soil moist and slowly decompose to improve the soil. Again, don't let the amendments get too deep, this can bury roots and cause other problems.

 

[Dr_dewey]

ammendments

i produce a lot of wood shavings from woodworking, and these are scattered around the yard so the soils get a good covering of shavings every year. will make a special effort to keep the soil enriched.

also noticed that every tree has borer holes so a merit treatment will be provided.

thanx again.