Saturday, August 14, 2010

Hoverfly Influx

This summer has seen an unsual abundance of hoverflies in my garden. The species that I have been able to identify have their numbers boosted enormously by the influx of migrants. The one in the photograph above is very easy to spot as it is black and white and is known as Scaeva pyrasti. The white markings on tergites 3 & 4 of the abdomen have a very characteristic shape and should be checked so that they reach much forward at their inner ends (centre of abdomen) than at their outer ends. It is believed that this species is not a permanent resident but arrives here as a migrant and then breeds here.

Another instantly recognizeable species is Sphaerophoria scripta shown above. This is another species that is boosted in numbers by migration and is easily identified by the body being much longer than the wings (males only).

Finally, the easiest to identify and most abundant species in my garden at the moment is the Marmalade Hoverfly Episyrphus balteatus. It is the most frequently recorded species in Britain and Ireland and is recorded in all months in most years. No identification help is required with this species as it cannot be confused with any others.
All the above photographs were taken around the 28th July, and I'm waiting to here in the press if 2010 is the year of the Hoverfly migration.