Key for the identification of the known mines of British
insects (Diptera and non-Diptera) recorded on Stratiotes

1a > ? Leaf-miner: A number of short, rather broad corridors that enter the blade from the midrib. Pupation within the mine, mainly in the leaf base and the midrib. At the moment only adult flies can be separated from H. stratiotae..

On ? Alisma, ? Hydrocharis, and ? Stratiotes in Britain. Southern England including Cambridge, East Kent, Hunts and South Hants in Britain. Widespread in continental Europe.

Hydrellia mutata (Zetterstedt, 1846) [Diptera: Ephydridae].

1b > Leaf miner: Irregular mine, locally shallow, elsewhere much deeper, giving it a mottled appearance. In broadleaved plants the mine often begins as a blotch with stellate extensions, but sometimes as a very fine, shallow corridor. In grasses the mine often begins in the leaf sheath. The frass is very fine-grained, initially scattered, later in aggregates. The egg is deposited on the plant surface, and the empty egg shell remains visible. But the larvae are able to leave their mine and restart elsewhere, thus mines without an egg shell can be found as well. The larva also leaves the mine before pupation. Pupation takes place in a newly made, small, blotch mine without frass; this mine may be made in another plant (species).

Polyphagpus. On ? Alisma, ? Damasonium, ? Sagittaria, ? Bellis, ? Rorippa, Tropaeolum, ? Lychnis, ? Stellaria, ? Carex, ? Cyperus, ? Scirpus, ? Hydrocharis, ? Stratiotes, ? Lamium, ? Lemna, ? Allium, Arrhenatherum, ? Polygonum, ? Potamogeton, ? Veronica, ? Typha in Britain.

On ? Alisma, ? Damasonium, ? Sagittaria, ? Bellis, ? Rorippa, Tropaeolum, Lychnis, ? Stellaria, Carex, ? Scirpus, Trifolium, ? Hydrocharis, Lamium, ? Lemna, Allium, Papaver, Agrostis, Alopecurus, Apera, Arrhenatherum, Avena, Avenula, Brachypodium, Briza, Bromus, Calamagrostis, Dactylis, Desmazeria, Digitaria, Echinochloa, Eleusine, Elymus, Festuca, Gaudinia, Glyceria, Holcus, Hordeum, Lagurus, Lolium, Panicum, Phalaris, Phleum, Phragmites, Poa, Secale, Setaria, Triticum, ? Polygonum, ? Potamogeton, Veronica, ? Typha and Verbena elsewhere. Widespread in England. Also recorded in the Republic of Ireland. Widespread in the Palaearctic region. Also recorded from Nearctic and Australasian Regions.

Hydrellia griseola (Fallén, 1813) [Diptera: Ephydridae].

1c > Leaf-miner: Makes short, straight mines, with little frass. The larva crosses from leaf to leaf through the stem. It pupates in the stalk, rarely in the leaf.

On Callitriche and Hydrocharis in Britain and/or elsewhere (records ambiguous), Stratiotes in Britain and Potomegeton elsewhere. Recorded from Cambridge, East Suffolk, North Essex, West Norfolk and West Suffolk in Britain and Widespread in continental Europe.

Hydrellia cochleariae Haliday, 1839 [Diptera: Ephydridae].