Some kind of mite eating right thru seedlings

Esho

I had a few shoots in my greenhouse last year that had the stem almost eaten clean through.

I used compost from a bag that was in the greenhouse for this wears seedlings, and whatever it is ate right through the stem.

What could it be and how to get rid of it?

GrumpyMe

Slugs?

mr chips

Could also be the grubs of the crane fly - they lay their eggs as close as they can to the stem of a plant so that the hatchlings can eat something as soon as they're out.  The trick is to surround the young stems with a disc of card (e.g. cut from a cereal packet) about 3 or 4 inches in diameter.  This way, the grubs will die before they can reach your plants.
If it's slugs, completely surrounding the plant with a layer of crushed eggshell on top of the soil will do a lot to deter them, especially if the eggshells were baked before crushing as it makes them sharper.  Keep the shells every time you crack an egg and next time you're using the oven, pop them in there after you've finished whatever you were baking/roasting, close the door and switch it off - the residual heat is enough to do the job.  Then just crush them with a potato masher or whatever, store them and keep going till you've enough.

Esho

Thanks mr_chips. Def wasn't slugs , so I'll try the card. But thanks for the tip on baking the eggshells. I will do that, as I wasn't on the ball last year and just got three whole strawberries before the slugs and snails feasted on them.

Esho

Would those mites also eat leaves - they are feasting away on the leaves of my tomatoes.

looksee

Woodlice eat strawberries too.