Part 2: Nematocera and Aschiza not dealt with by Falk (1991) - JNCC

Scientific name Shirt 1987 Falk 1991 Reason excluded
Pipunculus hertzogi Rapp (as P. phaeton Coe in - Notable Taxonomy
Falk 1991)
Tomosvaryella palliditarsis (Collin) Notable At least 40 sites
8. The future
Although there is an understandable tendency for recorders to report mainly those species which are
known to be rare, it is hoped that this review, along with those on other groups of Diptera, will have the
opposite effect, and that it will, indeed, lead to a greater enthusiasm for recording not only the rare
species but also those which are considered to be common.
Regional variations in status have not been covered in this review. What is regarded as a common
species in some parts of the country may be rare in others, and such differences have frequently been
reflected in the views expressed by fellow dipterists during discussions in the preparation of this volume,
e.g. some Pipunculidae have been reported to be frequent in Scotland but to justify Lower Risk
(Nationally Scarce) status further south; this is the reverse of the state of knowledge in many fungus
gnats where there are remarkably few and scattered Scottish records for some species which are frequent
and widespread in England.
There are many species that, although not nationally rare or scarce, are by no means widespread and
common. These could perhaps be categorised as Nationally Local, but at present there is no provision for
the inclusion of these species in a review such as this. Even if there was a suitable category it is doubtful
if there is sufficient information available nationally to enable species to be assigned to it. Again, this
demonstrates the desirability of recording all species.
In common with other groups of insects, many species of Diptera exhibit fluctuating fortunes in their
populations over the years and it is clear from the historic records that some come and go, and there are
often peaks and troughs, sometimes separated by many years. This, too, should be a stimulus to increased
recording.
Reviews such as this are a contribution to what must inevitably be a continuing process; this is a
snapshot of knowledge of selected species at this time only. It is hoped that the result will be an upsurge
of recording.
In this connection, the recording schemes and study groups for British Diptera are listed in Stubbs (2003)
and are available from the Biological Records Centre, CEH Monks Wood, Abbots Ripton, Huntingdon,
Cambridgeshire, PE28 2LS and from their website (www.brc.ac.uk).
9. Acknowledgements
As indicated in the family introductions in Section 6, this work has only been possible with the assistance
of specialists in each group and on the support of many others.
As stated earlier, the information in this volume is based on the preliminary research undertaken by
Steven J. Falk and I am indebted to him for his efforts and the comprehensive basis for this work that he
provided.
Much of the introduction is based on the review of the Empidoidea by Falk & Crossley (2005) and
statements which apply equally to the present review are often repeated verbatim. The clarity of their
approach has been invaluable.
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