Herbivores and scavengers feeding on dead
vegetation or living plant roots.
Male: 12 mm. Female: 14 mm
Their common name comes from the fact that the
adults usually emerge around St Mark's Day, 25th April.
Bibio marci larvae are known to be root damage pests
of celery, asparagus, roses, saxifrages, lawn grass,
lettuce and Polyanthus.