Expert: C.L. Fornari - 3/18/2010

Question
I live in Oregon, and I am growing a little under 900 pansies (in pots) this year in my greenhouse. I discovered small holes in the leaves and little black bugs that fly around when I water. I don't want this to spread to all 900, so I have been setting the bug eaten ones outside and spraying everything with natural insecticide.
Is there anything else I can do?

Answer
Hannah,
You might have flea beetles, or the black bugs you see flying might be fungus gnats and unrelated to the holes. You've done the right thing by separating the damaged plants and spraying - the other thing you might do is to put yellow sticky cards (AKA Whitefly traps) that you can get at any garden center in the greenhouse. The black bugs will be trapped on those. Putting a product that contains Spinosad in the water that you water the pots with will help if it's fungus gnats, and there is some evidence that Spinosad (an organic insecticide) will also control flea beetles although I don't think that the product is labeled for that right now.  Spinosad is the active ingredient, not the product name, and it is like Bt but works on a wider range of larvae.

I hope this helps,
C.L.
C.L. Fornari
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