Susanna’s Wildlife Watch - April
Photo by Hilary Barton
On a sunny Sunday at the end of March, I saw a gorgeous jewel of an insect sitting on a leaf in the sunken garden. And it was a new one! It had a brassy thorax, yellow abdomen and black tail. It was sunning itself, so I could look at it closely. Its body was translucent, and the sun was shining right through it, like through coloured glass, so the leaf beneath it glowed yellow. I took some photos - easy, because it was sitting still! - and it turned out to be a Spring Epistrophe hoverfly. It’s a species that likes the sunlit edges of woodland. The females lay eggs high up on leaves, with sycamores a favourite tree - of course we have a huge sycamore at the top gate, so maybe that’s where this hoverfly began its life. When the eggs hatch, the hoverfly larvae spend three weeks eating aphids, sleeping all day and eating all night apparently. Then they go into a sort of hibernation, and overwinter in leaf litter. Great that we left the leaf litter lying around this past year! And when spring comes, the new adult hoverflies emerge. It was brilliant to see this one, resting in the sun. They feed on nectar and pollen, and are especially keen on hawthorn flowers. Our new hawthorn isn’t flowering yet, but hopefully it will soon and the Spring Epistrophe hoverflies will have plenty to eat.
Hoverflies are brilliant pollinators, which the RHS says are “often overlooked”. Naturespot, a citizen science website, says not many people record them. There are 280 species in the UK, about half of which have larvae that eat aphids, which is helpful, whilst others develop in water and eat detritus, which is helpful too, recycling nutrients. The hoverfly lagoons hopefully help them, and the pond of course. Still other species of hoverfly develop in dead wood. Our dead hedges, log piles and the standing deadwood should be helpful to them.
So far, in St John’s Garden we have identified seven species of hoverfly with the help of Konstantinos of Pollinating London Together, as well as a range of entomologists who assist via the iNaturalist platform. Last year we got Marmalade Hoverflies, Thick-legged Hoverflies, Many-Tufted Boxers, and Footballer Hoverflies. The Footballers are one of the "Target Ten” species in the Clerkenwell Pollinator Path project. This year we have seen three new hoverfly species already: Spring Epistrophe, Grey-spotted Sedgesitter, and Eupeodes Aphid Eaters or Broadtail hoverflies. You can see photos of what we've seen, and add your own, at iNaturalist here.
Look out for the hoverflies - and the bluebells - when you're next in the garden and we hope to see you soon!