October 17th, 2011 | by Dave Ingram | 4 Comments
Published in Backyard Garden, Flies, Invertebrates, Macro Monday
Tags: British Columbia, Courtenay, Gardening, Golden-haired Dung Flies, Scathophaga stercoraria, Seaweed, Vancouver Island
We’ve recently added a winter layer of seaweed to the garden and, in addition to the nutrients returned to the soil, it has attracted a whole host of new flies.
These gorgeous golden flies are Golden-haired Dung Flies (Scathophaga stercoraria). Appropriately named, they are a striking golden brown in full sunlight (these images were taken in partial shade late in the day) and, like the name suggests, lay their eggs in dung or wet decaying vegetation. The rotting seaweed does have a particularly pungent odour, which might explain why they’ve turned up in numbers this week.
I spent some time in the garden sitting on the grass and observing the dung flies in action at eye level in the raised garden beds. Many were coupled together with the larger male on top of the rather plain, smaller female. The pairs would move around on the seaweed, stopping occasionally. The male would then slowly and deliberately move its front legs forward, describing an arc in front of and along the sides of the thorax of the female. I’ve found a couple of accounts that state that the male holds the female’s wings during copulation but didn’t witness this.
Despite their somewhat unwholesome selection of material to lay eggs in, these flies are definitely beautiful and very interesting to watch up close. You just have to hold your nose while taking a closer look!