Answer: Although many insects chew holes in leaves, if the holes are tiny, the most likely culprit is the flea beetle. These tiny black beetles, true to their name, will jump off plants if disturbed, making a positive identification difficult. One way to determine if these are the culprits is to cover the inside of a cardboard box with bright yellow paper, then smear petroleum jelly on the paper. Hold the box upside down and brush it over the tops of the affected plants. The flea beetles will jump toward the yellow paper and get stuck on the sticky surface. (If you do this frequently, you may be able to keep the population in check.)
Flea beetles are generally a problem on young plants only; mature plants are able to withstand the damage without compromising yields. Next year, protect newly seeded beds and young plants with floating row covers.
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