Anasimyia contracta Claussen & Torp, 1980
This species was confused with A. transfuga before the review by Claussen & Torp (1980); older records are therefore suspect unless a specimen has been re-examined.
Biology & ecology:
A lowland species associated with beds of emergent vegetation growing at the edges of ponds and slow moving rivers. The larva is unknown, but is thought to live in the saturated, decaying vegetable material found around the base of such plants. Adults seldom stray far from breeding sites and can be found sitting on leaves and visiting flowers. Adults fly in early summer with a peak in June and July.
Widespread in the lowlands, especially along the courses and floodplains of river systems. The scarcity of records in northern England and Scotland appears to be genuine. The lack of records in the SW peninsular seems strange since it is widespread in the lowlands of Wales.
Status & conservation:
Like many wetland species, there has been a downward trend in frequency over the last decade or so.