RORIPPA. Yellow-cresses and Water-cresses. [Brassicaceae]

Eleven species of Rorippa are recorded in Britain. These include the native Great Yellow-cress (R. amphibia), Northern Yellow-cress (R. islandica), Narrow-fruited Water-cress (R. microphylla), Water-cress (R. nana), Marsh Yellow-cress (R. palustris) and Creeping Yellow-cress (R. sylvestris).

Rorippa nasturtium-aquaticum is treated as Nasturtium officinale by Stace (2010).

The British ephydrids Hydrellia griseola, Hydrellia meigeni and Hydrellia ranunculi are recorded on Rorippa by Irwin and Chandler in Chandler (1978) and the British drosophilids Scaptomyza flava and Scaptomyza graminum are recorded on Rorippa by Chandler, 1978, but it is not clear whether the host associations are British or Foreign.

See BRASSICA.

Elsewhere the agromyzids Chromatomyia horticola, Liriomyza strigata, Liriomyza sativae and Phytomyza rufipes and the drosphilid Scaptomyza flava and are recorded on Rorippa.

No non-Diptera miners are recorded on Rorippa in Britain.

Elsewhere one British non-Diptera miner, Ceutorhynchus minutus, is recorded on Rorippa (see below)

Key for the identification of the mines of British
non-Diptera recorded on Rorippa

Note: The larvae of mining Coleoptera, Hymenoptera and Lepidoptera may live in a corridor mine, a corridor-blotch mine, a blotch mine, a case, a rolled or folded leaf, a tentiform mine or sandwiched between two more or less circular leaf sections in later instars. Larva may pupate in a silk cocoon. The larva may have at least six legs (although they may be reduced or absent), a head capsule and chewing mouthparts with opposable mandibles (see video of a gracillarid larva feeding). Larvae of Hymenoptera and Lepidoptera usually also have abdominal legs (see examples). Frass, if present, never in two rows. Unless feeding externally from within a case the larva usually vacates the mine by chewing an exit hole. Pupa with visible head appendages, wings and legs which lie in sheaths (see examples).

1 > Leaf-miner: Rather small, untidy, full depth, often branched corridor, often close to the leaf margin. Sides irregularly eaten out. Frass in a greyish-green central line that is interrupted from time to time, sometimes partly in strings. In times of rain the frass may run out and appear greenish. Usually several mines in a leaf (Bladmineerders van Europa). The legless larva is rather shapeless, with a well-sclerotised head. The body is whitish; head greyish brown with Y-shaped lighter marking. Pronotum with a pair of brownish shields. The mandibles have two teeth (Bladmineerders van Europa).

Mine of Ceutorhynchus minutus on Raphanus sativus Image: Willem Ellis (Bladmineerders van Europa)

Recorded on numerous genera and species of Brassicaceae, Capparaceae, Resedaceae and Tropaeolaceae, including Cochlearia, but not yet on Rorippa, in Britain and Rorippa elsewhere. Widespread in Britain and continental Europe. Also recorded in the Republic of Ireland.

Ceutorhynchus minutus (Marsham, 1802) [Coleoptera: Curculionidae]