From Martin Evans
The beauty of hoverfly recording is that you do not have to stand in the cold of winter with your telescope like bird watchers, you do not have to stay up most of the night with your mercury vapour trap like moth recorders. To record hoverflies you can just stroll through flower-rich meadows or along green lanes and woodland edges on warm sunny days.
There are at least 260 species of hoverflies in Britain. Some of them are large, brightly coloured and very easy to recognize, while others are just one amongst a dozen very similar species and are extremely difficult to identify.
In the past, recording these flies was left to just a few expert dipterists who worked from keys to identify them, but in 1983 a book was published by the British Entomological and Natural History Society that was to make their recording a task that any reasonably competent naturalist could achieve.
The book was British Hoverflies written by Alan Stubbs. It had new illustrated keys and species accounts, but what made it exciting was the high quality colour plates painted by Steven Falk. Although a specialist subject, the book has been reprinted several times. There have also been two supplement books written to update the original, with new information, keys and newly discovered species.
British Hoverflies is the major British work on these species, but another smaller book Hoverflies by Francis Gilbert (part of the Naturalists’ Handbook series) is also a useful text. This book also has keys, species accounts and plates (the latter also by Steven Falk) of the commoner species, but its strength is in the way it describes the biology and life cycles.
From these books you will soon learn that hoverflies can be identified by the false vein along the centre of the wing and that the vein that runs parallel to the trailing edge of the wing closes off the adjacent cells. You will soon become familiar with what is and what isn’t a hoverfly and not need to check these details.
Apart from the pleasant summer strolls you will have while looking for these flies, a large number can be recorded by setting up your deck chair beside a flower bed in your garden. As long as you do not fall asleep you are likely to see a wide variety of species visiting the flowers or basking on the leaves.
The Ice Plant Sedum spectable, Marjoram Origanum spp., Michaelmas Daisies Aster spp. and other species that are also attractive to butterflies are all likely to attract hoverflies. Fennel Foeniculum vulgare is another plant that is attractive to some of the larger flies such as Volucella zonaria, but it is tall and you will have to keep getting out of your chair and standing up if you want to study the species on this plant.
For the more energetic it is worth taking a gentle walk along a woodland edge or along a ‘green’ lane where the hedgerows are mature and wild flowers are abundant. Many species such as Volucella pellucens will be recorded hovering just above your head while others will be basking on tree trunks or on the lower leaves of trees, but the most productive place to search is probably on the flower-heads of umbellifer species such as Hogweed Heracleum sphondylium.
Very little equipment is necessary to record hoverflies. For many of the larger brightly coloured species the British Hoverflies book is all that is necessary, but if you intend to record on a more regular basis it will be worth investing in a net, a 10x hand lens and some small plastic or glass tubes so that you can study the flies more carefully. For the more serious entomologist a binocular microscope and a camera will also be useful.
Books
Stubbs, Alan.E. & Falk Steven J. British Hoverflies 2nd
Edition (BENHS, 2002).
Gilbert, Francis S. Hoverflies 2nd Edition (Naturalists Handbooks
5, Richmond, 1993).
Websites
www.wildguideuk.com
www.david.element.ukgateway.net