The main distribution of this species is in the south and west of
Britain and Warwickshire is more or less on the boundary of its
Prior to 1991 there were a few records confined to the rivers
and Stour; 1992 marked a turning point. That year vigorous
were found on the Stour and Blythe and a new population on the
reaches of the Leam.
In 2000 it was recorded on the River Dene at Combrook. In 2003 it
recorded close to
on an upper tributary of Thelsford Brook and in 2004 on a small
stream on the Warkwickshire/Oxfordshire boarder close to
and Paddle Brook, Stretton on Fosse.
continues its slow expansion of range with records for 5 new sites
2010, 1 in 2011 and 3 in 2012. However, it remains a
fairly rare and locally distributed species in the county.