Image of Entomobrya atrocincta Schött 1896

Description:

This deal is minute. It's shown in context in the second photo - sitting at the narrow end of the wedge located at 7 o'clock on the mushroom, which is 2 cm across . So insect length perhaps 0.5-0.7 mm. Thrip? I couldn't find anything resembling it, but perhaps i'm on the wrong track altogether