Pamela: Flea beetles are most damaging to seedlings though, if the numbers are high enough, can slow the growth and development of your larger tomato plants. They do have cycles with in a year and from year to year. See this for more information: https://pnwhandbooks.org/insect/vegetable/vegetable-pests/common-vegetable/vegetable-crop-flea-beetle 

They can be carefully vacuumed off plants but then they have to be killed and, probably, you wouldn't get nearly all of them. Even insecticides are not perfect in controlling them. One you might try is one with spinosad, a naturally derived insecticide. Two common brand names are Monterey Garden Insect  spray or Captain Jack's Dead Bug Brew.  Both are considered organic. Read and follow all label instructions. They have a 1 day interval between spraying and consumption of the tomato. Hope this helps. Chip Bubl OSU Extension/Columbia County  <personal data hidden> <personal data hidden>

Thank you!!!!!