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My yellow squash and zucchini are infested with both striped and spotted cucumber beetles. I don't think I can use Sevin Dust anymore because I've already started harvesting them. I tried food grade diatomaceous earth, but I don't think it's working. (But it did start raining a couple days after I applied it)

What are my best options for killing them?

They're also attacking my tomatoes and eggplant.

Edit: I have not tried Neem oil, I have not tried pyrethrum.

Organic is not the same as safe. I don't necessarily care if it's organic or not. But I do care whether or not it's safe apply to plants that I'm actively harvesting from. I'm picking squash and zucchini as often as daily.

Application details would be nice too. And along with that, how labor and time intensive it is to use these products. If I have to spray the bugs individually (which doesn't seem all that practical, they do have wings...) that's going to be a different experience than spraying the plants or applying a powder.

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Neem oil, and pyrethrum? – Grady Player Jul 18 '12 at 4:28
@GradyPlayer are you asking me? Because if I knew, I wouldn't be asking. – Tim Jul 18 '12 at 5:38
lol... asking if you had tried them... i haven't ever used them on beetles. – Grady Player Jul 18 '12 at 21:28

I've never had a problem with cucumber beetles nor do I have any experience using the following products but this is what's listed in my current Johnny's Selected Seeds catalog as their recommendations for cucumber beetles. They are all marked as organic.

The Safer Brand site lists their Tomato and Vegetable Insect Killer as their recommended product for cucumber beetles which you can read about here.

*Can't be shipped to Canada or Alaska and has restricted uses in California.

Of the products listed I'd try the Tomato and Vegetable Insect Killer or Insect Killing Soap not only because they're the cheapest options but also because it should be easy to find locally and I've had good results with their other products in the past. I haven't checked the other products but these say you can use it up until the day of harvest so you should be safe eating from the plants you're currently applying this to.

Their instructions on use are to thoroughly moisten all plant surfaces where insects are feeding or resting and apply every 7-10 days when insects are present or as needed to prevent damage.

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From "The Organic Gardener's Handbook of Natural Pest and Disease Control", p262-263:


  • Remove and destroy crop residues
  • Cover with floating row cover (and pollinate by hand)


  • Apply kaolin clay, especially to leaf undersides; reapply after rain
  • Handpick or vacuum beetles
  • Apply parasitic nematodes to soil weekly to control larvae
  • Spray with pyrethrin -- as a last resort, since this will kill beneficials like bees.

For both species, larvae and adults can spread wilt and mosaic virus.

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