On St Georges' day the sun finally peeped through the cloud cover to encourage the insects to emerge and the birds to sing. True to the date Hawthorn or St Marks' Flies were on the wing chasing each other around.
Male St. Mark’s flies are around 12mm in length with clear wings, large eyes and long dangly legs. Interestingly, the male’s eyes are divided by a groove and have separate connections to the brain. This allows the males to use the upper eye part to look out for females and the lower part to monitor their position in relation to the ground, allowing them to hover in the same position. The shiny black male flies are very conspicuous, with long dangling hind legs.You can often see them when they congregate in big swarms flying slowly, up and down, at around head height – trying to attract females. Females are bigger than their male counterparts at 14mm in length with smoky brown wings and much smaller eyes and legs.
Life cycle
The St. Mark’s Fly has a very short adult life cycle, being in flight for approximately only one week. The majority of their time is spent as larva in the soil. During autumn and winter, larvae feed on rotting vegetation which they chew with their strong mouthparts. In springtime the males emerge first and the females a few days later. After mating, females lay their eggs in the soil and die soon afterwards.
Swarms of St. Mar'ks flies may be annoying in the early spring, but they are very useful creatures, they feed on nectar, making them important pollinators of fruit trees and crops.
Feeding St. Marks Flies (Bibio marci) © Rodtuk
Bluebells are still out in the woods and margins of the woodland at Northward Hill, but don't hang around if you want to see them at their best, they don't last for ever and before you know it they're gone until next year
The North Kent Marshes are a very special area and worth preserving at all cost.