Hoverflies are valuable insects and particularly over the last two decades, they have started to impact on a wider range of people than just specialists. Hoverflies are known and recognised not just for their striking colours, remarkable hovering behaviour and flower visiting habits but also because of their roles in providing ecological, environmental and economic services.
Their ecological and economic roles and services centre on their ability to pollinate plants in both natural and agricultural systems and predatory larvae that reduce economic losses in cultivated plants by attacking sap-sucking pests like greenfly and scale insects. Hoverfly values also involve plant feeding hoverfly larvae, either as potential agents of weed control or, occasionally, as being pests themselves. Additional services include larvae that have a completely different way of life and are recyclers in a wide range of terrestrial habitats and to their largely untapped potential as composters of organic wastes from agricultural and industrial processes. Environmentally hoverflies are of importance because in many habitats, they consist of groups with varying levels of specialism and/or endemic species that are of biodiversity significance in themselves or that can act as indicators and monitors of climate change and habitat or site quality. Some hoverflies are of conservation significance because, unfortunately, they are endangered by human activities and require action to ensure their survival. As such, they can act as proxy for whole communities and functional groups so that by conserving them, much other wildlife is also conserved.
Hoverfly research has undergone a renaissance over the past 20 years which is due to a better realisation and understanding of these ecological, environmental and economic roles and services, vastly improved understanding of basic species taxonomy particularly in Europe, and application of new techniques for investigating hoverflies, such as assessing their evolutionary relationships using phylogenetics and DNA sequencing.
Hoverflies are diverse and beautiful and their habits and behaviour provoke both wonder and curiosity. Many people have developed an interest in hoverflies and actively contribute to the growing but still, gap-riddled, collective knowledge of these colourful and generally beneficial insects. A much greater number of people have heard of hoverflies and may even be able to recognise them but beyond this, hoverflies remain a mystery.
Until now hoverflies are one of the few insect groups with a growing appeal but with no book devoted to their natural history. The aim of this book is to fill this gap and to take readers into the world of hoverflies by giving an account of their major features, attributes, habits and behaviour.
1. Introduction
2. Adult Form and Function
3. Early Stages
4. Origins, Features and Faunas
5. Hoverflies in Europe and Britain
6. Colour and Mimicry
7. Flowers and Pollination
8. Zoophagy
9. Saprophagy and Phytophagy
10. Populations and Life Cycles
11. Habitats and Communities
12. Hoverflies and Humans
In 1976, after completing a joint honours Biology/Philosophy degree at Keele University, Graham Rotheray moved to Cardiff University where he completed a PhD on hoverfly parasitoids under Professor Mike Claridge. In 1979 he moved to Liverpool Museum as Assistant Curator of Invertebrates and in 1981, went to the University of Maryland, USA to undertake a post doctoral position researching natural enemies of the Gypsy Moth. On return to the UK, in 1984 he became Head of the Entomology Section at the National Museums of Scotland, a position he has held ever since.
Francis Gilbert completed his undergraduate and PhD degrees at St John's College, Cambridge between 1975 and 1981. His PhD studied the morphology and foraging behaviour of adult hoverflies in natural and garden habitats, and particularly the possibility that competition structures hoverfly communities. After finishing his PhD, he went to the USA for two years as a Harkness Fellow, again studying the morphological structure of communities of adult hoverflies in Maine, Florida, Arizona and Oregon. He returned to a Junior Research Fellowship at Gonville & Caius College, Cambridge, but within a year had obtained a lectureship at the University of Nottingham, where he has remained ever since.