Flies

It is incredible but true that more species of fly have been found at Wicken Fen than any other group of animals. There are more fly species than all of the plants, fungi, birds and mammals added together. Flies are a very diverse group of insects and include hoverflies, soldierflies, houseflies, horseflies, assassin flies, midges, gnats, mosquitoes and craneflies.

So far, an amazing 1,894 species of fly have been recorded at Wicken Fen nature reserve.

Hoverflies might be the flies most familiar to us all. Many of these have black and yellow colours and are attracted to flowers where they collect pollen. There have been 118 species of hoverfly seen at Wicken (although 7 of these have not been recorded since 1980).

The National Trust is deeply indebted to Ivan Perry, an expert in the natural history and identification of Diptera (flies), who has been instrumental in carrying out the majority of the detailed survey work of this insect group at Wicken Fen.

New horsefly recorded at Wicken Fen
First record in Cambridgeshire since 1909

The rediscovery of Tabanus Autumnalis in Cambridgeshire
(INSECTA, DIPTERA, BRACHYCERA)

Adrian Colston

On the night of the 11.vii.1998 a single female of Tabanus autumnalis entered a mercury vapour moth trap running in the garden of 15 Lode Lane, Wicken in Cambridgeshire (TL 565706). This specimen was collected for identification.

During the morning of the 15.vii.1998 another female was caught in a bird ringing net on Wicken Fen National Nature Reserve (TL 559707) by the Head Warden Martin Lester. This animal was dead. This animal represents the first ever specimen recorded at Wicken Fen NNR.

On the afternoon of 16.vii.1998 a further female became trapped within the William Thorpe Visitor Centre at Wicken Fen (TL563705). This animal was subsequently released. On the 22.vii.1998 another female was again trapped in the same mist net, again this animal was dead.

The record from 15 Lode Lane appears to be the first record for Cambridgeshire (Vice County 29) since 14.vi.1909 when a male was collected by Francis Jenkinson in Cambridge.

Wicken Fen has been worked extensively for Diptera over the decades most recently by Ivan Perry and as Tabanus autumnalis is such a large and distinctive animal it is unlikely to have been missed. Indeed grazing of the Reserve by cattle, sheep or horses has historically never occurred. However in 1991 the National Trust purchased 37.4 hectares of arable land known as Priory Farm adjacent to the existing Reserve and converted it to wet grassland. In the spring of 1997 cattle were introduced for the first time to graze the land. It is therefore likely that the recent records of Tabanus autumnalis coincide with the introduction of cattle to the site.

I would like to thank Ivan Perry for confirming my initial identification, informing me of the significance of the records and providing the historical record for the species in Cambridgeshire.