I like to spend the summer months exploring aspects of the natural world that tend to be neglected by other observers in Wharfedale. Hoverflies represent an ideal group that merit further study, especially as these diverse insects are readily attracted to flower heads in parks and gardens, making them easy to locate.
I first became interested in hoverflies during my university days when, during a summer vacation, a fellow ecology student and I made a record of the species occurring within a mile of our student digs.
Equipped with nets, plastic containers and various magnifying devices, we headed out on most days into the garden and adjacent fields and woods in search of specimens to add to our ever-growing list. By the start of the autumn term we had managed to locate over 50 different species – including many strikingly-patterned individuals and some that our identification book told us were ‘rare’.
Hoverflies are an attractive insect group to study for a variety of reasons. There are about 270 species in Britain and many are impressively patterned in bright colours. Their docile nature means that it is often possible to approach them very closely when they are at rest, especially when they gather on open flower heads to feed. Indeed, I have frequently been able to coax cooperative individuals to crawl onto my finger, allowing me to study their delicate features through a hand lens.
Many hoverfly species are bee or wasp mimics. Although they are not equipped with stings themselves, they have evolved to look like stinging species to make them appear more ferocious to potential predators and competitors.
The advent of digital photography has equipped insect enthusiasts with a valuable new tool to help make identifications and monitor populations. I have been able to put a name to numerous ‘mystery’ species by scrutinising their features on close-up images taken in the field.
When I first became interested in hoverflies over twenty years ago, no English names had been suggested for individual species, which meant that any conversation on the topic with fellow enthusiasts soon required the use of tongue-twisting scientific names. Even the commonest species – Episyrphus balteatus – proved quite a mouthful!
More recently some English names have been proposed for the commoner British hoverflies, so I can now discuss more easily the distribution and habits of our most widespread species, the delightfully named ‘Marmalade Hoverfly’.