In reply to TobyA:
It’s lil’ brother does seem to work on midges as well. But since we only have so few of them around, can’t give a definite answer.
Just as a reminder, these things work If you start ’em up in good time (15mins for the small one), and then don’t move them. Perfect for bouldering or a crag with numerous routes in the same area. But perhaps not that useful for the leader.