Our earliest knowledge of the Purple Hairstreak in the county is largely confined to information referred to in publications by Ellis (1890) and Day (1903). During this late nineteenth century period the butterfly was considered to be “of very rare occurrence in Cheshire” with the only sites listed as Delamere, Eastham, Wallasey and Malpas. There was then a gap of many years until Smith (1948) published details of “half a dozen” at Ollerton in 1936, but stated that the butterfly was still “very rare”. Even during the period from 1961 to 1982 the Purple Hairstreak was still only being recorded regularly at one site in the county, just south of Chester, with Rutherford (1983) commenting that it was “rare and local, but being a rather shy insect it may not be quite as rare as records suggest”.
Since the mid-1990’s data from the Cheshire Butterfly Recording Scheme has shown a dramatic change in the status and distribution of the Purple Hairstreak. Contributors have during this period recorded the butterfly in 212 tetrads (2km x 2km squares), representing 31% of tetrads in the county. Whilst the majority of these sightings emanate from the west of Cheshire, the insect is also being regularly recorded in smaller numbers from most areas of suitable habitat. There are several possible reasons to explain the apparent improved status of the butterfly in Cheshire with the following often being quoted:-
- increased recording activity in recent years
- greater identification skills of contributors
- an improvement in atmospheric conditions
- changing climatic conditions
- a genuine northerly range extension
It seems quite likely that a combination of reasons have contributed to recent distribution changes with evidence showing that the butterfly has now moved into several areas where it had been searched for unsuccessfully in earlier years. Whilst this insect can now be classed as relatively common in the county it is also true to say that many recorders will rarely, if ever, have seen a Purple Hairstreak. Perhaps this is not too surprising as it seldom descends to ground level, but feeds on aphid honeydew from treetop leaves. Unlike other butterflies it is most active on warm sunny evenings when it can be glimpsed flitting through the canopy with a characteristic jerky flight reminiscent of other members of that family. For anyone wishing to observe this insect a pair of binoculars is extremely useful
The Purple Hairstreak can most frequently be found in woodlands or even hedgerows where oak trees grow. Most colonies in Cheshire have been recorded on Pedunculate Oak (Quercus robur), although at some sites it utilises Sessile Oak (Q. petraea) or Turkey Oak (Q. cerris). Quite often the butterfly can also be observed feeding on nearby Ash trees (Fraxinus excelsior). It is a single brooded insect that normally flies throughout July and August. Earliest county sighting was at Chester on 17th June 2006 and the latest at Newgate on 11th September 2000.
Day, G.O. (1903). A list of Lepidoptera found in the counties of Cheshire, Flintshire, Denbigshire, Carnarvonshire and Anglesea.
Ellis, J.W. (1890). The Lepidopterous Fauna of Lancashire and Cheshire.
Rutherford, C.I. (1983). Butterflies in Cheshire 1961 to 1982.
Smith, S.G. (1948). The Butterflies and Moths found in the counties, Flintshire, Denbighshire, Caernarvonshire, Anglesey and Merionethshire.
Written by Barry Shaw for News, the Cheshire and Peak Distrcit Branch of Butterfly Conservation magazine.