Drought reduces breeding success of the butterfly Aglais urticae

1. Published laboratory work suggests that Aglais urticae may be affected adversely by drought, as the larvae thrive on actively growing plants with high leaf water and nitrogen. 2. The weekly counts from the Butterfly Monitoring Scheme were used to test the hypothesis of an association between changes in abundance and drought in field data. 3. The analysis supported the hypothesis; breeding success of the summer generation from 1976 to 1995 was greater when the early summer weather was cool and wet than when it was warm and dry.