Tag Archives: St Mark’s Day

Saint Mark’s flies

Today, 25th April is St Mark’s day and I have never seen so many St Mark’s flies around us. Whether it is the couple of warm days we’ve had over the Easter or just a bumper year for these odd little flies I am not sure. One of the distinctive features of these flies is their dangling legs. They are found around woodland edges, hedgerows and wetlands.

Bibio marci

St Mark flies – Bibio marci

I think when I took these photos only the males were about. They have larger eyes and are blacker and smaller than the females.


The flies are harmless and feed on nectar so are also accidentally pollinators. They only have a short flying life cycle and spend much of their lies as larva in the soil when they eat rotting vegetation.

Bibio marci

Bibio marci