Vol 10 Part 14. An introduction to the immature stages of British Flies ...

for higher degrees. This has resulted in several valuable and comprehensive studies, e.g.
Dixon (1960) and Hartley ( 1961) on Syrphidae; Okely ( 1974) and Pitkin ( 1988, in part)
on Sphaeroceridae.
Unfortunately all families do not lend themselves to concentrated short term study
and may require a long and continuous effort before a reasonably comprehensive
treatment can be achieved, e.g. Brindle's work on Tipulidae (1952- 1967) and the 25
years required to produce Skidmore's (1985) book on Muscidae. Some fine work has
been done in Europe especially by Dusek & Laska (1967, summary) on Syrphidae, and
Hennig (1943a-1956) and Schumann (1953- 1974) on Cyclorrhapha.
The identification oflarvae beyond family level has thus remained a difficult process
requiring a knowledge of, and access to, a very widely scattered literature. In this
Handbook keys to families and sub-families of final stage larvae are given as far as this is
possible. In some families further keys and illustrations are given to facilitate identification
to genera and sometimes to species. For the latter the aim has been to include
species of medical and economic importance, species commonly involved in the everyday
enquiries of environmental health officers or the general public (including non­
British species regularly introduced in imported food, etc.) and those species most
frequently encountered as larvae during ecological surveys or of special value in teaching
biology at school or university level. To further these aims some bionomic keys are
given at appropriate points where a limited number of species occur in a restricted
habitat. In a section on ecology there are some listings of families, genera or species to
be found in specific habitats which, by restricting the possibilities, should facilitate
more rapid identification by reference to the figures alone. A full index provides rapid
access to ecological information in the text. There are brief general comments on eggs
and pupae, and illustrations showing their diversity of form.
The following comprehensive specialist works on larvae are of value in identification.
Hennig (1948- 1952) is well illustrated and lists the world species described as
larvae up to that time with a full bibliography. Peterson (1957) treats Nearctic species
but Teskey (in McAlpine et al., 1981) does so in much greater detail. Seguy (1950)
gives much detailed information on all aspects of fly biology arranged under subject
and habitat and similar information for British species is given in Stubbs & Chandler
( 1978) which includes a key to families of larvae (by Brindle & Smith). Brauns ( 1954)
deals with terrestrial Diptera larvae and pupae and is well illustrated. Teskey
(1984) gives a well-illustrated key to aquatic Diptera larvae. Oldroyd & Smith (in
Smith, 1973) give a key to families of larvae of medical importance. Smith ( 1986) deals
with species of forensic importance including those found on carrion (human
and animal). Koppen ( 1972) covers some agricultural pest species. Askew (1971) and
Clausen (1940) review parasitic Diptera. References to particular families are given in
each section below.
As this book goes to press a very important two volume work has appeared on the
immature stages of the Cyclorrhapha (Ferrar, 1987) and also part 2 of the Manual
of Nearctic Diptera (McAipine et al., 1987), also covering Cyclorrhapha, has been
published.
Acknowledgements
In his Introductory Handbook to the Diptera the late Harold Oldroyd (1970b)
expressed the hope that a volume dealing with the early stages of flies would eventually
be produced in this series. Indeed, we had intended that we should cooperate in such a
venture but his early death sadly prevented this. Nevertheless many of his ideas
expressed both verbally and in his writings, especially in his unique book The Natural
History of Flies (1964), have stimulated an interest in the biology of flies among
Dipterists, including the present author.
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