The influence of temperature on river fly phenology based on historic records.

First appearance dates of three river flies (Mayfly, two caddis flies: Grannom and Welshman's Button) for 1834-1931 were abstracted from the records of a chalk river fly fishing club in southern UK. First appearance dates of the terrestrial invertebrates Mole Cricket and Glow-worm were also abstracted. Appearance dates were related to monthly mean air temperatures by multiple regression. For all but Mole Cricket, modest but significant advances in phenology were detected in years with warmer temperatures; typically of the order of 3-6 days/°C. However, limited meteorological data were available for this historic period and we suggest that improved models require additional and more fine scale local weather and environmental data.