Key Sites: Summer Leys, Pitsford Reserve, Welford Quarry Ponds. The Emerald has a scattered distribution, preferring sites with dense vegetation, which tend to be older gravel pits. Generally not present where fishing is common, which limits its distribution along the Nene Valley.

Characteristics: The Emerald Damselfly is characteristically different from all other species in the county, with its bright metallic green body and its habit of resting with wings held open. Found in areas of dense emergent reeds, the Emerald is often hard to find and probably under-recorded as a result. Both sexes remain concealed, rarely if ever leaving the protection of the vegetation, where Its green colour blends well with its surroundings. 

Eggs are laid in high summer and hatch the following spring for emergence in June the same year. This results in rapid larval development, with high activity in the water, which makes them easy prey for fish. The distribution map shows a decline in this species since the late 1990's, possibly as a result of increased fishing in the Nene Valley Gravel Pits--it now appear to be absent from pits it was recorded in during the early '90's. The floods of the Nene Valley in 1998 displaced fish from the Nene into the Pits, and may have contributed to this decline.

The short larval development time is adapted to breeding in temporary ponds, that are prone to drying in high summer, which makes some colonies transient in nature. It may therefore readily disappear from historical breeding site without too much effect on the County's population.

County Status: Under-recorded. The recent spell of very hot summers have caused many ponds to dry out before the larvae have matured and emerged, and this is beginning to hit population numbers. Where possible, such ponds in nature reserves should be managed to maintain water levels throughout the year.

Emerald Damselfly

Lestes sponsa

Male Southfield's Farm Marsh, July 2006