Some sort of mite. If they move quickly they are predators. If they sit there, they are sucking on the plant. If you see mite damage on plants, look for mites at site of damage.

Dan

They do move very quickly. However, when I just googled "predatory mites," it seems that most mites are supposed to be just tiny: barely visible. These are clearly large enough to capture with just a regular camera so I'm just not sure what they are. They do have four sets of legs, so some kind of mite I agree.... but what!?

What is the extent of the mite damage on your plants, and do these mites match the mites found at the location of the mite damage?

Dan

There had been a stem/branch on the first plant I found the mites on that was damaged, but it's possible it was something else, as that one had a leaf touching the soil. The rest of the plants do seem OK with no damage so far. I have only sprayed the one plant that one time 2 weeks ago. Weird, never knew there were clover mites. Do any others agree?

Well, they don't look so clover mite-ish to me, but I sure would like to see more pictures of the little things. Maybe a different angle would help.

The little 'egg globes' you're finding in the soil are most likely the prills of a slow release fertilizer such as Osmocote. Hard when first mixed into the soil, they absorb water through tiny micro pores and burst when the volume of water exceeds what the outer shell can hold. This is how the fertilizer is released for plant uptake. Since the prills are different sizes, fertilizer is released at different times over several months.

I have not put Osmocote into the soil... however, I did use Miracle Gro potting mix. Maybe those are built in. I'll try to get more pics of my odd little red mite-like guys.

Did you grow the tomatoes from seed or purchase the plants from a nursery? (Osmocote is often present in nursery/garden center plants.)

The reason I'd like to see more images is that the shape of your little things doesn't seem quite 'right' to me. However, I sure don't know what else they could be (aside from the clover mites), considering their location and behavior. They are phytophagous (plant eaters) and in large numbers could possibly cause problems for young plants. They really aren't considered a pest, though.

I'm thinking clover mites.

tj

Here is a link that might be useful: Mite be

The mites are nowhere to be found right now! It's been very wet and rainy, so perhaps they'll come out again if/when the sun ever does. But I'm much less worried now, thanks for all the help. I'll update photos if they come back.

they are clover mites, they do not bite humans or pets, they prefer grass, but can also feed on garden plants. if you have a huge infestation they can leave discolored spots on plants, but if plants are well maintained they will not do damage. i have some around my house! my plants are doing well.