Oystershell scale

[Beng]

Was out removing old needles from a cork bark black pine today and noticed the tree has a moderate infestation of oystershell scale on the bases of the needles far more then I could scrape off in a realistic amount of time. What do you all suggest to deal with it on pines this time of year. Should I use something like Merit WP or good old neem oil, will neem oil penetrate their hard shells? It lives in a protected cold house that bottoms out at 40 degrees.

Thanks
Ben

 

[0soyoung]

So called 'dormant oil sprays' have long been the standard remedy for scale. IMHO it works by suffocating the little bastards. The pesticidal chemical part seems unessential, but ought to get to any of them that move around and somehow didn't get oiled.

 

[Beng]

Thanks, i went with neem oil for the needles/bark and a application of merit to the soil. Took as many off by hand as i could. They like to hide inbeween the 2 needle pairs which is kinda hard to reach.

Ben

 

[october]

Sorry to hear this... Oyster shell scale is the king pin of the scale world... That shell makes them almost immune to many pesticides. In this case, you are definitely doing it right by removing as many as you can see. Keep removing and then spray. You might have to do 2-3 spraying and removal sessions that are about 3 weeks apart each.

Here is something I posted in response to a juniper scale issue. I have never used this on pines. However, I would imagine it would not hurt the pine.

I have been dealing with scale on junipers for almost 10 years. I will offer this. The home made solution works very well. You will have to spray a couple of times probably every season, but it is worth it. Especially at the very end of winter.

These are the general ratios. You can use a little more oil and you can use as much as 2 tablespoons of soap for bad infestations.

1 tablespoon of vegetable oil
1 1/2 tablesspoons of dishwashing liquid. You can use palmolive or ivory. I have used both.

Mix this in a gallon of water. Then pour this solution in a spray bottle. Now add 1 capful (from the alcohol bottle) of alcohol. Shake well. Spay all surfaces, under and over branches, interiors, trunk etc..I usually leave it on for about 24 hours then shower the tree off very well. In a few weeks, I'll sometimes repeat it again. I would not spray in temps that are below freezing or above 90. However, you can offer some protection for the trees anyway. After spraying, I usually keep the tree out of direct sun for a few days and after the tree is thoroughly hosed off.

I also had success with Bonide all seasons horticultural oil years ago. However, I switched to this because it is not toxic at all. It can be sprayed inside, outside and no PPE in necessary.

Rob

 

[GrimLore]

That solution looks like a good idea and I will modify it if I ever need it by replacing the Vegetable oil with Mineral oil. The Mineral oil does not contain anything to allow anything to "feed" off it. 8.99usd at the local pharmacy and handy for treating Baking surfaces, utensils, and cutting boards after a quick vineger bath.
We have a 192 year old 18 inch thick stonewall building so natural ways to stop and then not allow any types of unwanted growth are needed.
Also I must be careful note as it has been commited on - There are many natural and handy ways to do things - ALWAYS be careful not to allow these Alchemist inventions to infiltrate the soils as they will most certainly affect the chemical balance.

 

[october]

Hi Grim... I have never used mineral oil.. I do know that there has never been any sort of ill effects with the formula. If you do substitute, it might be, as always, a good idea to spray a small, inconspicuous part of the tree to see if it reacts negatively. You never know with trees.

Rob

 

[Beng]

Arg evil little buggers.... scale and borers have to be my two least favorite bugs....

I was wondering why the bases of some of the needles were looking off colored the other day. Now I know why. Oddly my other black pine doesn't have one scale on it and they live next to each other on my bench.

My mix today was one teaspoon of pro-tek in a quart spray bottle, 1 1/2 teaspoons of bio-neem pure neem oil, 1/2 teaspoon of dishwashing soap. Is there any benefit of the other oils over neem? The Merit 75 I usually dilute at a low strength of one pinch "it's the measurement size beneath 1/8th on a measuring set" per 2 gallons bucket. I used it to deal with mealy bugs pretty successfully on a camellia i'd brought home from a nursery this fall. Except with that mix I had done a lot like you suggested and added 2 tbsp of rubbing alcohol to the spray bottle as well. Camellia has thick waxy leaves, i'd be scared to use it on a significant pine of mine till someone else who's tried it on black pine chimes in?

Will repeat the oil spray and scraping twice more before spring in hopes i get them all.

 

[Dav4]

I was wondering why the bases of some of the needles were looking off colored the other day. Now I know why. Oddly my other black pine doesn't have one scale on it and they live next to each other on my bench.

QUOTE]


FWIW, the only time I've found scale on my JBP was when it was unhealthy (other JBP on bench was fine). I firmly believe weaker trees are more likely to suffer from scale and other insect infestations. Any chance this tree has been under any other stress other then that caused by the scale?

 

[Beng]

Your right, this tree was repotted in late fall. It wasn't doing great the candles weren't elongating "probably because it has bad scale but i didn't notice it then" like they should so i moved it up to a larger pot for the winter. They started elongating just a couple weeks ago.

 

[october]

Be sure to isolate this tree from all other trees. Not only bonsai, but landscape trees as well. Also, do not let any water residue run off or splash from this tree to other trees. Scale can spread.

Also, have you noticed if there were ants present in the area over the last few months? Ants carry scale eggs.

Rob

 

[Beng]

It's as isolated as it can be I think in my coldhouse. Its a semi cascade shohin not touching any trees and it's sitting on the only copper stand I own. There isn't any watering of the needles in the greenhouse in winter, they stay dry. Except when I brought it Inside to treat it yesterday. It's cold here now a pretty consistent 40-45 degrees in the cold house, nothing should be crawling around this time of year. Outside it's in the mid 20's to 40's. No ant problems for years. In spring it'll be moved outside of the coldhouse before many of the deciduous trees I'll keep an eye on it. I'm pretty persistent so should be able to rid myself of them on one tree...

 

[Beng]

Winged Euonymus Scale

I think i identified the species wrong. Found a few more and looked at them through a 50mm lens (poor mans loupe.) It looks exactly like the picture on the left of this image.

http://1.bp.blogspot.com/_8xC9bwq6AVU/SecJ0mSp43I/AAAAAAAAH58/gAXf0C5XWgQ/s400/winged+eonymus+2.JPG

Apparently that is the female Euonymus Scale (Lepidosaphes yanangicola, Kuwana.) Each scale has a yellow/brass metallic tip to it like in the above pic. My tree doesn't have any of the whiter colored males seen in the right side picture though. Perhaps cause it's mid winter and only the females overwinter. Brown oystershell scale doesn't have this yellow/brass tip unless I just haven't found a good picture of it. Otherwise they look very similar, I don't have much experience with scale insects but it's my best guess. Seems strange they'd be on a black pine though...