Q & A

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Eric Vinje

Hi Kenneth –

While there is nothing on the Monterey Bt label about grazing cattle I do not see why you couldn’t apply it here without concern. Bacillus thuringiensis is a biological insecticide that kills worms and caterpillars, including armyworms, but has no effect on people, birds, earthworms, or beneficial insects such as honeybees and ladybugs. Approved for organic use, this easy-to-mix liquid concentrate biodegrades quickly in sunlight and can be used on fruits and vegetables up to the day of harvest.

Read the EPA’s Fact Sheet on Bacillus thuringiensis subspecies kurstaki (PDF) here.

Apply Monterey B.T. when worms or caterpillars are first noticed, then repeat at 5-7 day intervals while they are active. Use more frequently to control heavy infestations and reapply after heavy rains.

Hope this helps!