Help! What is this and how do I get rid of it???

Controlling pests of bamboo

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Matt in TN
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Help! What is this and how do I get rid of it???

Post by Matt in TN »

On my new-to-me seedling moso - it is growing well, but all but the newest leaves seem to be getting this to one degree or another. I was thinking I'm finally getting to see the infamous "bamboo mites", but it doesn't quite look like the other pictures posted here. Any ideas?

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stevelau1911
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Re: Help! What is this and how do I get rid of it???

Post by stevelau1911 »

Looks like thrips to me. They are tiny insects that feed on new leaves that are still unfolding and they are either invisible or look like white dust. Young plants under 1year old are especially vulnerable since their developing leaves don't have the waxy barrier yet.

I had an infestation about 4 weeks ago which I exterminated with ortho bug spray. I probably did some overkill since I used 3X concentration and ended up killing some good shoots along with leaf burn on the newer leaves. Recommended concentration should be more than sufficient. All the bamboos have now recovered without any more signs of damage on the newest leaves.
Mackel in DFW
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Re: Help! What is this and how do I get rid of it???

Post by Mackel in DFW »

I believe hosing down the plant with blasts of water can help on thrips and aphids, in doing a quick google search.
Alan_L
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Re: Help! What is this and how do I get rid of it???

Post by Alan_L »

What feature is the problem? The dark spots? The white spots? The holes? I'm not sure what you're asking about.

If it's the dark spots, I don't think that's thrips. Thrips damage appears to be white or silvery on most plants from what I'm reading. Maybe it's different on bamboo, but I doubt it.
Matt in TN
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Re: Help! What is this and how do I get rid of it???

Post by Matt in TN »

It looks to me the problem starts with small brown spots, which turn into larger brown spots, which turn into white spots, and then turn into holes in the leaf. Would it hurt anything to go ahead and spray it down with pesticide that kills thrips (among many other bugs)? what's the downside to spraying pesticide?
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Alan_L
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Re: Help! What is this and how do I get rid of it???

Post by Alan_L »

As long as you don't use too strong a concentration it shouldn't hurt the bamboo. Depending on the type of pesticide, in general the downsides are: possible hazard to humans and animals; will kill beneficial insects too.

Do you see any evidence of insects at all, even very small ones? Try shaking a leaf over a white sheet of paper. If you don't see any insects, and the problem does not continue, you may want to just wait until next year since the growing season is just about over. If you'll be bringing the plants inside and growing them under lights, that's a different story. If you are bringing them in, you may want to choose your pesticide carefully. Read the label(s)!
stevelau1911
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Re: Help! What is this and how do I get rid of it???

Post by stevelau1911 »

One easy way to determine if it is a thrip problem is to inspect the unfolding leaves to see if there's a powdery dust and holes. Thrips can only do damage to leaves that are still tender. They suck the juices out of the leaves which may turn into brown spots after sun exposure and will leave a hole if the spot is large enough.

Pesticides shouldn't cause any leaf damage as long as the recommended dosage is applied. I got carried away and used triple dosage which was strong enough to melt some of the rising shoots, and significant damage to the leaves that were still tender.
Matt in TN
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Re: Help! What is this and how do I get rid of it???

Post by Matt in TN »

Alan_L wrote:will kill beneficial insects too.
This is probably a dumb question, but for bamboo - what is a beneficial insect and why?

I don't phsycially see any insects, but the problem does seem to be getting worse instead of leveling off or getting better. I need to go out there with a magnifying glass and a white piece of paper - I thought I saw some small webs on the underside of the leaves, but not nearly as many as the bamboo mite pictures show.
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Markj
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Re: Help! What is this and how do I get rid of it???

Post by Markj »

Matt in TN wrote:
This is probably a dumb question, but for bamboo - what is a beneficial insect and why?

Probably one that eats the one that eats bamboo :D
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Alan_L
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Re: Help! What is this and how do I get rid of it???

Post by Alan_L »

Beneficial insects are the ones that:

1) eat insects that are harming your plants
2) provide some useful service like pollination (not applicable to bamboo)
3) improve your soil, like earthworms (not applicable in this case)

I'd also include "any insects you like having around" to this list. :D
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Re: Help! What is this and how do I get rid of it???

Post by dudley »

ladybugs and lacewings would be two good choices for beneficial insects.
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wescue
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Re: Help! What is this and how do I get rid of it???

Post by wescue »

This is nothing
its nothing at all

otherwise bamboo looks fine, just fine
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