[viettaclark]

My lettuces bought as cut and come again from Lidl and now quite big are one by one weakening, going limp then biting the dust.
They are in troughs that have been in the shade during the heatwave. It's not cutworms. When I rootled the STEMS are being eaten at the base and I think it's the load of tiny grey lice-like things that I found in the soil at the base of the plants.
There has been alot of whitefly but they don't eat stems do they?
Could the lettuce seedlings have carried a hidden pest?

[gobs]

They could have and what you are describing sounds like these critters just moved into on already decaying plants. This is possible.

Post a pickie, someone might have seen this before!

Lettuce can die just of the heatwave of summer though.