I'll try that. Thanks.

If you don't find anything underneath, be alert for the presence of leafhoppers, thrips, and other more mobile small pests.

Thanks. I didn't see anything under the leaves. What would be a good remedy if it is any of those bugs?

First, I would examine undersides with a magnifying glass just to make sure I wasn't missing very young/small pests.

Second, I would observe carefully to see whether the damage is increasing. If not, the pest may have moved on or been put into balance by predators.

If damage is ongoing and you're sure the pests are not the kind that live on the plant, the easiest thing may be to use insect cover since your plants are still small. When the plants get larger, uncover them and see whether the problem is still there.

Or, since they're not flowering yet, so there's little chance of hurting pollinators, you could try something like DE, which will work indiscriminately on hard-bodied insects and bugs. Spinosad will have activity against young caterpillars, may have activity against thrips, and some other pests, but won't do much for leaf hoppers, grasshoppers, most beetles, etc. There are, of course, stronger pesticide chemical options which I personally try to avoid so don't have any experience using, but you can find information on these online.

The best way to mount an effective response is to observe well and figure out which pest you're dealing with. You might contact your local extension to see what tomato pests are currently active wherever you are.

Thanks gorbelly. I'll give the tomatoes a good inspection tomorrow morning.