1331       Acentria ephemerella [Denis & Schiffermüller 1775]  WATER VENEER

A species found across much of Britain, the larva living beneath the surface of ponds, lakes and more stagnant parts of rivers, and feeding on canadian waterweed (Elodea canadensis), pondweeds (Potamogeton spp.), stoneworts (Chara spp.) and filiform algae; respiration takes place through the skin. The female has rudimentary wings, although a fully winged form, larger than the male, is occasionally observed at light. The males fly vigorously over the surface of the water at night, and occasionally disperse on the warmest nights in huge numbers, coming to light and being found dead in the base of the moth trap the following morning. In Dorset, the moth is widespread and locally abundant near freshwater habitat. There are many instances of short-range dispersal to localities well away from water.

1345       Elophila nymphaeata (Linnaeus, 1758)  BROWN CHINA-MARK

A widespread species in Britain, the larva feeding beneath the surface of ponds and lakes on pondweeds (Potamogeton spp.), frogbit (Hydrocharis morsus-ranae), bur-reeds (Sparganium spp.), water-lily (Nymphaceae) and other aquatic species. In Dorset, the moth is frequent locally in pond and slow-flowing river habitats where broad-leaved pondweed (Potamogeton natans) is dominant, and in acid mire where bog pondweed (Potamogeton polygonifolius) grows. The national norm is for a single brood from late June to August, but a partial bivoltine cycle is suspected in Dorset, with two overlapping broods between early June and mid-September, much as occurs on the Continent. The moth occasionally flies some distance away from its core watery habitat.

1348       Parapoynx stratiotata (Linnaeus, 1758)  RINGED CHINA-MARK 

 A local species restricted to southern Britain, the larva feeding beneath the surface of ponds and lakes on pondweeds (Potamogeton spp.), Canadian waterweed (Elodea canadensis) and other aquatic species. In Dorset, the moth is local and at low density along the margins of lakes, ponds and slow-flowing portions of rivers. The moth also colonises wet flushes and ditches. The moth occasionally disperses over short to medium distances; the following records refer: Portland, at MV light on 18 July 1997, 24 August 1999, 26 June 2003 (M Cade).

1350       Nymphula stagnata (Donovan, 1806)  BEAUTIFUL CHINA-MARK

A species found across much of England, Wales and southern Scotland, the larva feeding beneath the surface of ponds and lakes on bur-reeds (Sparganium spp.), water-lily (Nymphaceae) and other aquatic plant species. In Dorset, the moth is local, and colonises the margins of ponds, lakes and portions of slow-moving rivers. Acid mire is an additional habitat colonised by the moth, and in localities such as Oakers Wood, Morden Bog and St Leonards Peats, bog pondweed (Potamogeton polygonifolius) is a likely host foodplant. The national norm is for a single brood in July and August, but a partial bivoltine cycle is suspected in Dorset, with two overlapping broods between mid-June and mid-September.

1354       Cataclysta lemnata (Linnaeus, 1758)  SMALL CHINA-MARK

A species of stagnant water habitat in England, Wales and southern Scotland, the larva feeding on duckweeds (Lemna spp.). In Dorset, the moth is very local, colonising ponds at Hengistbury Head, Eastern Lake on Studland Heath, open freshwater reedbed at Lodmoor, and water meadows at Wareham. The national norm is for a single brood between June and August, but a bivoltine cycle is suspected in Dorset, with moths on the wing over a three-month period; the species is double-brooded on the continent. The moth regularly disperses over short to medium distances. The following light trap records refer: Walditch, on 18 July 2003 (M Parsons), West Bexington, on 18 August 1994 (R Eden), Portland, on 27 July 1994, 25 August 2001, 10 and 23 August 2003 (M Cade), Freshwater Bay, on 23 August 2003 (J Chainey).