Answer: It is really difficult to control bud worms because they are within the sepals of the unopened flowers where insecticides can't reach them. So, you will need to try to control the next generation. Bud worms eat their fill and then exit the flower buds and pupate in the soil (or mulch) beneath your plants. Rake or otherwise break up the soil beneath the plants on a regular basis to expose the pupa to the elements. Sometimes you can tell a bud has a budworm by a tiny little hole in the unopened bud. If you find any, remove them from the plant and squish the bud, then toss it in the garbage. If you see the green caterpillars, pick them off the plants or use Bt (sold as Dipel). It is effective against caterpillars but won't harm beneficial insects. Best wishes with your petunias.
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