scale on shrubs

Discussion in 'Pesticide & Herbicide Application' started by shawns mowing, Mar 30, 2002.

  1. shawns mowing

    shawns mowing LawnSite Member
    Messages: 11

    what is scale and how do you get rid of it ? I noticed it on shrubs. Thanks Shawn.
  2. BigJim

    BigJim LawnSite Senior Member
    Messages: 382

    Scale is a common pest on shrubs and trees,spraying oil and or Orthene will clean them up,they also usually have a black sooty mould all around them,this will disappear when the scale are gone.There are also many websites devoted to this pest,this is one .

  3. Ric

    Ric LawnSite Fanatic
    Messages: 11,969

    Big Jim

    Great website and great post. let me add that scale will be killed by just one good treatment but will not fall off. If you scrape off the scale and squeeze them between your fingernails you can tell if they are dead. If they are dry then they are dead. If juice comes out they are alive.

    Jim US gov websites are for US tax payers. Got your return ready yet.:D
  4. vegomatic40

    vegomatic40 LawnSite Senior Member
    from 6
    Messages: 406

    While it is highly dependent on the type of scale (I think there are better than 7000 different species), I think it is best to identify the type of scale. Most plant materials that are prone to scale problems, usually get the same type of scale. Ex.-Cottony Maple scale on Maples. Take a sample to the local Ag. extension office for postive ID. Take the sample with a branch of the tree/shrub that is being damaged as this will help them narrow down the species and recommend treatment(s). Armoured scale should be in the "crawler" stage. This is the stage of developement just after the eggs hatch and they have not yet secreted a waxy covering that can protect them from Horticultural oils and insecticides. Hit 'em when they are vulnerable! While the verdict is still not in on how Hort. oil, Dormant Oil or Superior oils work, it is supposed that it smothers them by restricitng respiration. Be careful not to overapply the oil (max rates of 1-2.5% are recommended) or to apply to "Blue" Junipers and conifers such as Blue rug Juniper, Blue spruce and some maples. I have talked with several plant pathologists that believe overappliation or too frequent app.s can cause a problem of gas exchange (carbon dioxide to oxygen etc.) and can cause defoliation. Also, watch out when applying in warm weather. Use lower rates during warm/hot weather and try to schedule during the early am cool hours. Hope this helps.
  5. Ric

    Ric LawnSite Fanatic
    Messages: 11,969


    Got to disagree with you on early morning applys of oil. Mid morning and afternoon sun can burn plant leaves. I prefer late afternoon-evening closer to dusk applys. Morning dew and irrigation rinse the oil and lessen the change of sun burn. late afternoon or evening applys stay wetter longer and can be more effective.

    Like all of nature timing is key. Knowing the plant specie and the pest that attack them (and there life cycle) is what makes us Pros. Big Jim said oil and Orthene and I have found that effective on adult armored scale. Orthene is a fast acting non translocating systemic insecticide and scale are a sucking insect. At present time we are having an out break of Sago Scale on our sagos. This is a very tiny scale that reproduces very quick. Plants look like someone spray painted them. They hind at the base of the plant and re-infect it after treatment. Merit gives long term suppression but regular treatment are needed for control. That my .02 I am not trying knock you just add to your great post.

    Jim: remember April 15th is the day. :D :D
  6. Russo

    Russo LawnSite Senior Member
    Messages: 287

    Quality post, BIG JIM.
  7. vegomatic40

    vegomatic40 LawnSite Senior Member
    from 6
    Messages: 406

    You are probably right about doing the app. in late afternoon or dusk. I once had a customer that had Manhatten Eou., Foster Hollies and Compacta hollies all eaten up with scale. Since I had only gone "independent" 1 year previous, I only had one 200 gal. setup to supplement my turf program/equipment. This was in June of 1994 and it was a real scorcher outside. I mixed a 1.25% Hort. oil with Orthene to get the crittters in the am before I left for my lawn route. The truck sat in the parking lot for probably 10-11 hrs before I returned in the pm and had promised to treat the customer. Treated about 6-6:30 that evening and returned 2 wks later to check on scale activity. They were toast but noticed some minor defoliation on the Fosters and Compactas. Customer was unconcerned since the scale was history but I had remembered it was only a 40 gal. fill and the JD9C felt hot in my hand when I did the app. Anyway, I try to do oil apps only in the late fall or early spring but as you know there are always new sales. Forgot to add, if you don't get to the underneath sides of the leaves and do a thorough job the scale will likely come back.
    Got any ideas on Mites? Have had problems the past few years with Two-spotted Red spider mites on Eounymus Elatus (Burning Bush) and stumped for new ideas. Have tried Oils in all seasons, rotated miticides (although our choices are getting smaller) even injected Merit just prior to sap rise. These little suckers are tenacious. Feel I am killing the predator mites and now of the opinion I won't do anything and just see what happens. Any ideas
    PS Look for Orthene and all the other organophosphates to get yanked soon just like Dursban etc. It's coming!
  8. Ric

    Ric LawnSite Fanatic
    Messages: 11,969


    Spider Mites can be a pain in the @&&. on holly, junipers, and evergreens in general for sure. I have found two thing that work well on them.

    1.) Insecticidal Soap which give a reasonable knock down but not a whole lot of residual. I like to mix 1.5% soap & 1.5% oil as a standard shrub and tree mix. This is a Tree Hugger special that get 95% of my problems. Insecticidal Soap is not only an insecticide, and miticde but also has fungusicidal value. UHS makes a oil called Citrus Wrap and it is a very fine oil. It has good heat tolerant. I use a lot of Citrus Wrap on citrus trees.

    2.) Talstar T & O is also a miteicide that works well and has a little more residual. At $164.00 a gallon it sounds expensive, but at 0.4 oz per 1,000 sq ft it is the Dursban replacement. It has some Tree Hugger value also. It is harmless (quote-unquote) to mammals, but can and will kill fish.
  9. Lance Takara

    Lance Takara LawnSite Member
    Messages: 73


    Have you actually been able to control (totally get rid of) the scales on the sago palms? How often are you having to retreat sago? At one time they were one of the most "bulletproof" plants. We've been able to get decent control by removing all the leaves to get thorough coverage. Fortunately, we've been permitted to remove the leaves.
  10. Ric

    Ric LawnSite Fanatic
    Messages: 11,969

    Lance Takara

    Last year sago scale started in Miami and has moved north at a very quick rate. So in is still new to us. Cotton scale has always been on sagos but never very bad. Our biggest problem with sagos has been fungus untill now. A bout a month ago I went to all day semiar and haft the time was spend on sago scale.

    Bottom line: Orthene, Oil and Merit Merit Merit. Some of the guys are even deep rooting Merit. One even said he poured granule around base which is unlabeled uses. Scale likes to hide in the pupps so be sure to soak every part down. I have had success on real bad cases by cutting all the frons off and soil drench of Merit. But even though the sago are growing back it is to soon to say I have complete control. Sago are first on my scouting list. So far I luck enough not to have a reoccurring or new out break on the sago I treated. Hopes this helps. Do you have any tricks??

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