# insect problem on cherry laurels



## cmland (Jan 2, 2013)

I have been seeing this insect problem on multiple cherry laurels (Prunus laur. 'Schip') on a property. There are a lot of laurels and do not want this to spread. Having trouble identifying. Psyllids? Thanks in advance for any help.


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## Castenea (Jan 3, 2013)

There are at least two different scales on those branches.

The fuzzy white is likely prunicola scale. Possibly white peach scale. Treatments for both are similar the only difference is the timing, one of the scales enters crawler stage 2-4 weeks after the other.

http://ipmnet.umd.edu/nursery/docs/Scales-UnivOfMD.pdf


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## TreeGuyHR (Jan 23, 2013)

Castenea said:


> There are at least two different scales on those branches.
> 
> The fuzzy white is likely prunicola scale. Possibly white peach scale. Treatments for both are similar the only difference is the timing, one of the scales enters crawler stage 2-4 weeks after the other.
> 
> http://ipmnet.umd.edu/nursery/docs/Scales-UnivOfMD.pdf



Great reference. I treated minute cypress scale on juniper for a client last summer with Safari as a basal bark spray, but may not have made much of a dent. It was mainly after the crawlers had settled. I'll go with the oil for adults and the other compound for the crawlers this spring, as the Md document recommends.


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## Urban Forester (Jan 25, 2013)

TreeGuyHR said:


> Great reference. I treated minute cypress scale on juniper for a client last summer with Safari as a basal bark spray, but may not have made much of a dent. It was mainly after the crawlers had settled. I'll go with the oil for adults and the other compound for the crawlers this spring, as the Md document recommends.



I agree w/the oil, but I would try Onyx as a bark spray. We've discontinued Dinotefuran for scale, especially on pines as it seems to be much shorter residual than advertised. Fast translocation and equally fast dissIpation. Onyx is slower bark penetration, but much longer residual.


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## TreeGuyHR (Jan 25, 2013)

I'm gonna have to put these notes in the client file. I buy my stuff at target specialty Products in Portland, OR -- they are nationwide, so you probably have heard of them. 

*The bit below is not for non-applicator's ears;*

I have used a fair amount of Safari, but it is danged expensive -- at 12 oz. per gal, it's $100 a gallon (my cost) when you add in a dollup of Pentrabark. 

I'm ready to try a similar product that is cheaper.I have black pine leaf scale on pine that is a big problem, but this stuff is too expensive. I have used it as a prophylactic on some small cedars after two in the landscape died from bark beetles. Turned out to kill the adults that burrowed in to the treated trees either just after or before i applied it to the bark. 

Now, when you have a 120 ft., 4 ft. diameter ponderosa pine that is another story. Jury is still out on whether topping 40 ft, and taking more infested limbs out on one side and then spraying the top 15 ft. of trunk and 20 more limbs (uninfested or with just a few beetles) will save it. I actually hauled up and applied two loads of spray (6 gallons -- I put 3 gallons in a 4 gallon backpack sprayer, easier that way because it foams up). I don't know if I will ever do tha again -- had to wash two ropes, my climbing harness and flip lines, in addition to the sprayer, rain gear, and myself. I can post some pics, right now I am on the wrong computer.


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## Urban Forester (Jan 26, 2013)

TreeGuyHR said:


> ...I'm ready to try a similar product that is cheaper...



I shouldn't leave the impression its similar, its not. It has no ability to translocate through the zylem. It does penetrate bark, but it stays where you put it. The difference is very long residual, due to it being 23.4% AI. we use it at crawler stage and for bark beetles on high value trees, have had pretty good results. But it is cheaper, about $100 a quart, the fill is 24 oz per 100 for bark beetle and 12 oz for scale.


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## TreeGuyHR (Jan 26, 2013)

Urban Forester said:


> I shouldn't leave the impression its similar, its not. It has no ability to translocate through the zylem. It does penetrate bark, but it stays where you put it. The difference is very long residual, due to it being 23.4% AI. we use it at crawler stage and for bark beetles on high value trees, have had pretty good results. But it is cheaper, about $100 a quart, the fill is 24 oz per 100 for bark beetle and 12 oz for scale.



I am still interested. as you know, using a systemic in a tree already being attacked by bark beetles may not succeed. I performed an expensive experiment on that big pine by trying to combine it with pruning out all the infested trunk and limbs. I did miss some -- had to go back for two more faded limbs in the late fall ,and now there is another! 

An insecticide that stays put like a carbamate (Sevin) is still considered a preventative, working by killing the adults as they bore into the tree. So, the compound you are talking about will penetrate to the phloem and kill adults or larvae in the tree? I found that Safari probably did this, but don't know for sure if the chemical got in first or the adults did in those 3 -6 in. diameter cedars (western red, incense, and Japanese (_Chamaecyparis_). I did find that the adults' galleries were short, implying that the adults laid no eggs; also, the adults were dead and no larval mines were present.

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Too bad the client was into "perfect" stuff; she probably had the trees ripped out anyway because they lost some limbs; I'll have to check and see if they are still there. I beluev they would have survived, unless enough pathogenic staining fungus was introduced -- and not all bark beetles neccessarily introduce it, such as red turpentine beetle (_Dendroctonus valens_). I haven't gotten around to identifying the BB in these cedars, but it was very small, and may be the one that often kills arborvitae.

I have a lot of BB problems in my area, and an effective treatment that is reasonably priced is the "Holy Grail".


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