The mature male Scarce Chaser possesses pale blue pruinescence on the abdomen. Its eyes are blue. However, prior to maturation the male and female look very similar and are highly distinctive with vivid orange colouration, black triangular shaped markings on the upper surface of each abdominal segment and dark bases to the wings. Synchronised emergence usually begins towards the end of May, and adults can be seen on the wing until early August.
The Scarce Chaser is a species of Lowland river floodplains and usually inhabits slow-flowing, meandering rivers and large dykes. Occasionally mature gravel pits and nearby ponds also support populations. Inhabited sites characteristically have good water quality, which supports submerged and floating plants as well as prolific stands of emergent vegetation. Ovipositing females require areas of slow flowing open water, and the adults require some shrub or tree shelter.
L. fulva is scarce in Britain and is consequently listed under category 3 (scarce) in the British Red Data Book on Insects.
The Scarce Chaser is restricted to 6 main localities in Norfolk/Suffolk, Sussex, Wiltshire/Somerset, Cambridgeshire, Kent and Dorset/Hampshire. Populations appear to be stable and there is evidence that suggests that it may be expanding its range.
- The mature male Scarce Chaser possesses pale blue pruinescence on the abdomen and blue eyes. Prior to maturity the male and female look very similar and are highly distinctive with vivid orange colouration.
- The Scarce Chaser is a species of Lowland river floodplains and usually inhabits slow-flowing, meandering rivers and large dykes.
- Although scarce in Britain there is evidence that suggests that it is expanding its range.
- Length: 40-49mm
- May – July
The main threats to this species come from the inappropriate river management, river improvement schemes, pollution, eutrophication, over-shading, changing water levels and excessive boat traffic.
General management principles include maintaining inhabited sites and the adjacent landscape, controlling water quality, controlling boating activity, and undertaking monitoring and research. There are also best practice guidelines for managing inhabited sites, particularly regarding dredging, management of aquatic vegetation, and scrub control.