The Diptera of Lancashire and Cheshire: Craneflies and Winter Gnats
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The Diptera of Lancashire and Cheshire: Craneflies and Winter Gnats by Phil Brighton 32, Wadeson Way, Croft, Warrington WA3 7JS [email protected] Version 1.1 26 November 2017 1 Summary This document provides a new checklist for the craneflies and winter gnats (Tipuloidea, Ptychopteridae and Trichoceridae) to extend the lists of the diptera of Lancashire and Cheshire first published by Kidd and Bindle in 1959. Overall statistics on recording activity are given by decade and hectad. Checklists are presented for each of the three Watsonian vice-counties 58, 59, and 60 detailing for each species the number of records, year of earliest and most recent record, and the number of hectads with records. A combined checklist showing distribution by the three vice-counties is also included, covering a total of 264 species, amounting to 75% of the current British checklist. Introduction This report is the third in a series to update and extend the partial checklist of the diptera of Lancashire and Cheshire published in 1959 by Leonard Kidd and Alan Brindle1. There were two previous updates, in 19642 and 19713. The previous reports in this series cover the soldierflies and allies4 and the Sepsidae5, the latter family not having been covered in Ref 1. The reader is referred to the first two reports for the background and rationale of these checklists, as well as the history of diptera recording and available data sources. The description of methodology is also kept to a minimum in the present report: only significant differences from the previous publications will be outlined. The previous format of the tables and maps is continued. As before, the geographical scope is limited to the Watsonian vice-counties of Cheshire (VC58), South Lancashire (VC59), and West Lancashire (VC60). However to avoid confusion with the present political area of West Lancashire which lies within VC59, VC60 will be referred to as North Lancashire below. VC60 here is shorn of parts of south Cumbria which were covered erroneously in Ref 1. The Forest of Bowland largely remains in VC64, mid-west Yorkshire, and is also excluded. Taxonomic scope The UK Cranefly Recording Scheme (CRS) was set up by Alan Stubbs in 1973. This was followed by other Diptera recording schemes and then the formation of the Dipterists Forum (DF) in 1995. The scope of the CRS covered the following families: Tipulidae (long-palped craneflies): 87 British species Cylindrotomidae (damsel craneflies): 4 British species Pediciidae (hairy-eyed craneflies): 20 British species Limoniidae (short-palped craneflies): 221 British species in 4 subfamilies Ptychopteridae (phantom craneflies): 7 British species Trichoceridae (winter gnats): 10 British species The above numbers are taken from the January 2017 update of the British checklist on the DF website. The first four families are in the infra-order Tipulomorpha but the other two are more distantly related. The above listing follows the taxonomic order but in the tables below alphabetic order is followed. Draft keys were provided by Alan Stubbs around 1990 and have been revised recently by John Kramer in anticipation of publication of a long-promised book on British Craneflies. These keys also include notes on habitat in many cases. The Ptychopteridae are covered in a published atlas with keys6. An alternative method of keying has been used by Pete Boardman in his Shropshire Craneflies7 which covers 245 species recorded in that county: this also contains habitat notes. 2 These keys have superseded the relevant RES handbooks8, though these are still useful from time to time. A further invaluable source of information is the on-line Cranefly Catalogue of the World (CCW) which can be searched by species9. Sources of data and methodology The approach to collecting and analysing data follows that established for the soldierflies and allies in Ref 4. In addition to the data sources used there, records have been obtained from iRecord10 for the last ten years up to October 2017. Data has also been obtained from a survey of Astley Moss in 2010 by World Museum Liverpool11: these data do not appear either on the LRC or on NBN. The LRC data used was received in late 2016 or early 2017, and the NBN data was also downloaded during this period. My own data extend from 2012 to October 2017 and the duplicates thereof have been removed from the LRC data. The Harry Britten cards have been transcribed and checked against Ref 1 as done previously for the soldierflies and allies. This does create a certain amount of duplication with LRC and NBN data, but also adds much extra data particularly for common species. The numbers of records are as follows, amounting to a total of 14,961. Data Source VC58 VC59 VC60 Greater Manchester LRC 59 544 0 Harry Britten cards 1126 869 66 iRecord 24 0 99 LERN (Lancashire LRC) 0 71 125 Merseyside Biobank 64 489 1 NBN Gateway 1569 2093 1227 P Brighton 901 1441 34 RECORD (Cheshire LRC) 3824 261 29 WML 0 43 0 TOTALS 7567 5811 1581 Only limited validation has been carried out. A number of records of rare and implausible species have been omitted, primarily where the recorder was anonymous or a non-specialist. A number of other records were found with incorrect grid references and a few others had dates incompatible with the active dates of the named recorder. Such records have also been omitted. Uncertainties in other records are discussed in the species status notes in the Appendix. Overview of combined dataset The combined data have been analysed to provide details of recording frequency by decade and vice-county in Tables 1-4. The overall pattern is similar to that already found in Refs 4 and 5, though the records are more evenly split between VC58 and VC59. Table 1 shows the influence of Harry Britten during the 20s, 30s and 40s, with Cheshire visited rather more often than Lancashire. Alan Brindle’s records start in 1937 but were interrupted by war service. His contributions then extend from the 1950s through to 1982 when he retired from Manchester Museum. His records are strongly concentrated in areas of both the Lancashire vice- counties. It is also worth noting that he had a particular interest in cranefly larvae, and also other aquatic larvae. There was a lull in cranefly recording in the 1980s but during the 1990s and 2000s, the Cheshire numbers were greatly increased by Bill Hardwick. In the present decade, my own records have contributed at a similar level of effort in Cheshire, and rather more so in South Lancashire. 3 The maps in Tables 2a-c also show the strong influence of these recorders. In Cheshire the top four hectads are as follows: Hectad Description No. of records No. of species SJ57 Frodsham and Delamere Forest 1090 139 SJ66 Winsford and the Weaver Valley 1056 127 SJ88 South Manchester and Wilmslow 819 142 SJ98 Stockport, Marple and Poynton 776 109 The tally for SJ57 was significantly boosted by an invertebrate survey in 2003 for the Lost Meres and Mosses project12, and I have been carrying out further surveying there in the last few years13. SJ66 is the home square of Bill Hardwick and as well as the Weaver Valley contains the classic dipterising sites of Pettypool and Newchurch Common. SJ88 includes the Bollin Valley and Cotterill Clough: the latter was much frequented by Harry Britten and appears to have retained much of its diverse cranefly fauna despite its proximity to Manchester Airport14. SJ98 also owes its prominence largely to historic records by Harry Britten and others. Turning to South Lancashire, my home square SJ69 has become the most worked of all in the region but is relatively poor in species, as it has little extent of woodland and no upland areas. Alan Brindle worked extensively in SD73 and SD84 near to his home town of Nelson. SD61 was covered by entomologists based at Bolton Museum in the 70s and 80s and is the scene of renewed recording effort following the acquisition of the Smithills estate by the Woodland Trust. Hectad Description No. of records No. of species SJ69 NE Warrington and the Manchester 1189 109 Mosses SD73 Whalley and Padiham 559 126 SD61 NW Bolton and Winter Hill 397 107 SD84 Pendle Hill and Barnoldswick 318 96 A result of the much lower overall level of recording only two squares are highlighted in VC60: Hectad Description No. of records No. of species SD47 Silverdale area 573 117 SD63 Longridge area 165 74 There is no simple relation between number of records and the number of species recorded in a hectad. Apart from the intrinsic species numbers, this is affected by the increasing propensity of recorders in recent decades to record common species more thoroughly and at a higher grid resolution. Vice-county and Regional Checklists Tables 3a-c present the summary of the data for each of the three vice-counties in the format previously used for the soldierflies and allies and for the Sepsidae. The families are listed in alphabetical order rather than the taxonomic order presented above. The family Limoniidae has been split into its four British subfamilies. In each family or subfamily, species are listed alphabetically except for genus Tipula where subgenus names have been included. The earliest year of observation may represent the beginning of a range of years where no exact date was given in the historic records. Equally latest dates may represent the end of such a range. Table 4 provides a combined checklist for the whole region, comparing numbers of records in each vice-county. National conservation status classifications have been taken from the PANTHEON software, version 3.7.4, but have been simplified to just “rare” or “scarce”: a revised status review is 4 currently being prepared (see Ref 7).