Several confirmed sightings in sweep nets of tiny black-headed fireworm (BHF) larvae have been reported from late last week and over the weekend. Larvae are the same size as winter moth larvae (2 mm, ~1/16") except that they wriggle when touched or disturbed. This is the best (really, only) distinguishing feature at this point.
Both BHF and winter moth larvae are really exceptionally small!! but you should still sweep once the weather clears and try to see what you have on your bog.
Left: Larva next to stem on 3rd leaf.
Right: Larva on top of stem at leaf base.