By Phil Brighton

Introduction

Tanyptera atrata – female. Image by Richard (CC BY-NC 2.0)

Craneflies are familiar as the large daddy-long-legs which often come into houses in the autumn. They are mostly members of the Diptera superfamily Tipuloidea. However, the national recording scheme also covers the unrelated families Ptychopteridae (fold-wing or phantom craneflies) and Trichoceridae (winter gnats) because of their similar long-legged, long-winged and long-bodied appearance.

Adult craneflies can be caught in nearly all weathers, with a long season (including the winter for Trichoceridae). The habitat range is wide but they are particularly plentiful in woodlands and wetlands; some species have aquatic larvae. Craneflies are good ecological indicators and are useful for site evaluation in many habitats. They are also an important part of the avian diet, both as larvae and adults.

Recording of craneflies really got under way in the region with the work of Harry Britten between 1920 and 1950, particularly around Manchester and in the north of Cheshire. 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.

Are craneflies worth recording?

Craneflies were the first diptera group to be covered by a National Recording Scheme, started by Alan Stubbs in 1973. There are now roughly 200,000 records on the NBN Atlas from the Scheme and other sources. Keeping up the level of effort will enable studies of the broad effects of on-going changes in climate and agriculture over the decades, as well as of the health of special habitats.

The larger craneflies can be frequently spotted and photographed in the field with good prospects of getting an identification to species. Of course, sweep-netting in suitable habitats finds many more, particularly of the smaller species which go down to a few millimetres in size.

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 keys 1. An alternative method of keying has been used by Pete Boardman in his Shropshire Craneflies 2 which covers 245 species recorded in that county: this also contains habitat notes.

These keys have superseded the relevant RES handbooks3 , though these are still useful from time to time and can be downloaded for free4 . A further invaluable source of information is the on-line Cranefly Catalogue of the World (CCW) which can be searched by species5.

Recording Priorities

Many of our scarcer species have characteristic habitats such as lowland bogs, wet woodland, cloughs and other upland steams and seepages, many of which have not been surveyed since Alan Brindle’s time. As the maps below show, there are numerous poorly recorded squares in the wider countryside where locally based recorders could make a significant contribution to our knowledge.

Identification Keys and Other Information

[1] A. E. Stubbs, Provisional atlas of the ptychopterid craneflies (Diptera: Ptychopteridae) of Britain and Ireland, Natural Environment Research Council, 1993.
[2] P. Boardman, Shropshire Craneflies, Field Studies Council, 2016.
[3] R. L. Coe et al, “Diptera 2. Nematocera: families Tipulidae to Chironomidae”, Handbooks for the Identification of British Insects, Vol. IX, Part 2, Royal Entomological Society of London, 1950.
[4] https://www.royensoc.co.uk/out-print-handbooks
[5] http://ccw.naturalis.nl/