Annual report to the Wiltshire BRC April 2011
DIPTERA 2010
Click here to download a copy of this report
1. Annex 1 lists all Diptera records of my own or communicated to me by others (BL = Barbara Last; JN = John Notman; BH = Brian Harding.) If I have overlooked other contributions please let me know. I express our thanks to these indefatigable recorders.
2. There is probably little of real significance in the list this year, by which I mean records of notable (scarce or rare) species. It is worth remarking that Volcella zonaria (fam. Syrphidae) is, on the evidence, now well established across southern England, having been slowly extending its range over the last twenty years. The UK’s largest Syrphid, it is certainly a magnificent and unmistakeable insect, and both John Notman and I have recorded it this year. But in general this has been for me a quiet period; I had more enjoyment in Greece in May photographing some spectacular Mediterranean insects in several orders – but that is of little use to the Wiltshire BRC.
3. Unsurprisingly most dipteran records still relate to the Hoverflies (Syrphidae), and it would be valuable to begin to focus our interests in some of the other groups. But of course identification can become problematic without access to detailed keys. I continue to be especially interested in the Empidoidea, and have recorded in 2010 several species new to me, although not new to the region.
4. In my three years in the county I have yet to identify any habitats especially rich in the Diptera; we are well blessed for diversity and one could spend a lifetime doing justice to all the key areas and tying the species to the local geology and flora. Fortunately many – perhaps most – dipteran species are widespread and mobile enough to be found just about anywhere, and most records tend not to record or comment on the habitat or precise circumstances of the observation. In cases where there is known to be a close relationship between a species and, for example, its food plant , as there is with many Lepidopterans, the pattern will have been noted in the literature, but in the Diptera these relationships have been less well remarked.
5. Flies tend to make one think of spiders, and I must mention in passing, in case they are not recorded elsewhere, two sightings in 2010 of Argiope bruennichi, at Bentley Wood on 4 September and on Salisbury Plain on 12 September. Similarly to V. zonaria, this is a species which is spreading across the UK from the early sightings near the south coat. It is large and unmistakeable; the small party of our recorders in Bentley Wood that September Saturday morning crouched one by one at ground level, cameras at the ready.
6. Which reminds me: recorders who photograph Diptera may have to be reminded that it is not easy to give a secure identification on the basis of one photograph. It would be helpful if recorders taking photographs would at the very least make a note of noteworthy and specific features of the specimen and send them with their pictures. One hopes that in due course keen observers will capture the specimens and use specialist keys for identification, thereby improving their expertise.
Anthony Bainbridge
Wiltshire Diptera Recorder
Feb 2011
