More Nematus pavidus sawfly larvae

A few weeks back a colony of Nematus pavidus sawfly larvae fed up on one of the sallow in Wbx.  Recently a new colony appeared, founded I suspect, by an adult of one of the earlier larvae.

Today I noticed that there were three ages: the small white worms and their left behind eggshells, some rather large larvae but still with some growing to do, and some really big ones almost ready to pupate.

There was also a parasitic wasp (ichneumon or braconid) pottering about nearby and maybe looking for an opportunity to lay eggs in some of the sawfly larvae via that vicious-looking ovipositor.