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White bugs? on Dracaena Marginata

Posted by icedgoblin Hertfordshire, UK (My Page) on
Mon, Oct 25, 10 at 14:26

Hello,

Perhaps someone more experienced with plants will be able to assist me!
I have had a Dracaena Marginata for around 7 months now an it has been doing fine but has started to drop leaves and I suspect it may be down to an infestation of some sort.

There are what appear to be white bugs on the leaves and on the stems where the leaves join. When the leaves fall off there are quite a few on the base of the fallen leave. The leaves turn yellow and then dry out. There also appears to be brown patches on te leaves where the white bugs have been.

I have looked at pictures of spider mites and mealey bugs, but these do not seem to match and they are really small. There do not move at a speed that I can detect and always seem to be in the same spot. I have looked under a small pocket microscope and there kind of look like a grain of rice or a cotton q tip. I can't see any legs or any other "buggy" features.

I would be grateful to anyone to anyone taking the time to read this and offer any help!

I have tried to embed some images that I hope will work and will help identification.

Kind Regards

Geoff





Follow-Up Postings:

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RE: White bugs? on Dracaena Marginata

Those are definitely mealybugs and you have a pretty serious infestation.

Mix up a solution of 5 parts water and 1 part rubbing alcohol with a squirt of liquid dish soap. Then spray the hell out of the entire plant, paying particular attention to the crevices where the leaves join the stems. The entire plant should be dripping wet when you are done. If you are thorough, you may not have to treat it again, but be vigilant anyway and respray at the first sign of their return.

Will Creed


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RE: White bugs? on Dracaena Marginata

Hi Will,

Thank you for taking the time to reply. I had my suspicions but was not sure as they did not look like the images I could find!

I will give that solution a try and report back with the results.

Thanks again

Geoff


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RE: White bugs? on Dracaena Marginata

These look much more like a scale species than mealy bugs. Has this plant been outside?


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RE: White bugs? on Dracaena Marginata

I have to agree also that they don't look like mealy bugs. Mealies would not stay stationary either.

Billy Rae


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RE: White bugs? on Dracaena Marginata

Hi.........they look like mealys to me and treat the pot and under the rim of the pot, and any ridges the pot might have and if the plant is in a hanger treat that too...or the plant stand if its on a stand, mealy are everywhere and anywhere on or near the plant...good luck....linda


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RE: White bugs? on Dracaena Marginata

  • Posted by jean001 z8aPortland, OR (My Page) on
    Thu, Oct 28, 10 at 23:04

Not mealybugs. Scale.

The scale, itself, is the very small tan thing at one end of the elongated white things. And the long white things are egg cases, each with a 100 or more eggs.


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RE: White bugs? on Dracaena Marginata

OK folks, scale and mealybugs are close relatives and require the same treatment.

Scale insects do not produce any white cotton-like material that is clearly evident in the photos. Neither scale nor mealies move in a particularly noticeable manner and neither move after they mature and cover themselves with a hard shell (scale) or white covering (mealybugs). Scale lay their eggs underneath their hard shells not inside anything white.

Geoff - Ignore all this extraneous noise and treat the mealies as I have suggested.

Will Creed
Interiorscaper


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RE: White bugs? on Dracaena Marginata

Ohh, dear. You don't have much experience with a vast number of common scale species, do you, Will? It's understandable, since I believe that your primary expertise is in the care of indoor plants.

There are many different kinds of scale. Though most are notable for their hard shell, a very large number of them are identifiable by cottony residue and/or cottony egg masses. I'll attach a link to one of the most common of these species, just for you.

Granted, these two insects groups are closely related, I'll give you that. But they are clearly NOT mealybugs. Proper identification can make a difference, sometimes.

Here is a link that might be useful: Click here


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RE: White bugs? on Dracaena Marginata

Mealy bugs I have always dealt with have noticeable "legs" something the poster could not detect with the naked eye, or under a microscope. You can see a lot of detail with just a simple jewelers eye loop.
They might stay in the same spot, for a while, but they eventually will move around when their food source in that one particular spot dries up.

Billy Rae


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RE: White bugs? on Dracaena Marginata

  • Posted by tapla z5b-6a MI (My Page) on
    Sat, Oct 30, 10 at 17:04

Geoff - when it comes to pest ID, I've learned that when Dori and Jean talk, I should be listening. They are very good. More than once I thought I was being helpful by offering a pest ID, only to have my hat handed to me by one or the other because I was off target. Had the person asking the question relied on MY ID instead of theirs, I might have sent him off in an entirely inappropriate direction. These pests reminded me more of what pine or euonymus scale looks like than mealybug, but I figured one of the experts would be along soon to ID, so I didn't say anything.

Whoever came up with the verbiage that describes IPM (integrated pest management) thought it important enough that we correctly identify the pest, that they rated it as the #1 priority. U.C. Davis says "Identify your pest correctly to be sure the management method you choose will be effective. .... Find out if the pest is a problem that needs to be controlled and learn about its life cycle and biology."

As Dori pointed out, sometimes it's critical to correctly identify pests - sometimes not. For example, rubbing alcohol treatment might be effective on some types of insects (mealybug, e.g.) but not on certain types of scale. Or it might be effective on certain types of scale, but only at certain stages of growth. E.g., in some scale species, alcohol might only be effective on the crawler stage, with no affect on adults. Even different species of scale call for different types of treatment.

I don't believe it's mealybug, but if it was, a solution with (pure, cold-pressed) neem oil and rubbing alcohol in hot water, and a little Murphy's oil soap would be very effective (ask if you want the exact recipe). The same mixture would also be effective on scale, but I would opt for a perfect or all-season horticultural oil as the first line of defense against scale.

Al


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RE: White bugs? on Dracaena Marginata

*** 2 years later ***
Hello everybody,
sorry for bringing up this old topic.
I have a simialr issue and after searching for over 2 hours I landed here.
My Dracaena marginata also became populated with white bugs which I am unable to identify. They don't move at any detectable speed and are located only on the top parts of the leaves. Leaves soon dry out.
Comparing white dots to the scale or mealy bugs ditn't give much results. Now I tried with one solvent against Aphididae, Acarina and Trialeurodes vaporariorum and I am waiting for the results. Then I will try with the mixture suggested above. If anyone has an idea what those bugs might be, please respond.

icedgoblin's results would also help.

Here are photos:


http://aljaz.info/razno/dracaena_marginata_white_bugs_1.jpg
http://aljaz.info/razno/dracaena_marginata_white_bugs_2.jpg
http://aljaz.info/razno/dracaena_marginata_white_bugs_3.jpg


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RE: White bugs? on Dracaena Marginata

It's kind of hard to ID just from a picture - some of the bugs look like some kind of cottony scale, some look like mealy bugs. I see several life-stages, from crawler to adult. Could even be 2 kinds of bug - I don't think there's a law against that (though there certainly should be.) Whatever they are (I expect you'll get several opinions) treatment should be the same. I personally try not to use poisons, just a mixture of alcohol, soap ( I wouldn't use Murphys Oil, I would use a mild castille) and water, spraying to the drip point, and plan to spray once a week for 3 or 4 weeks, because you have to thoroughly disrupt the life cycle of the little critters.


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RE: White bugs? on Dracaena Marginata

Well, look it here!

No place is immune to Mealy, not even the UK.

Good luck with them suckers!

Mike


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