GENTIANA. Gentians. [Gentianaceae]

Seven species of Gentiana are recorded in Britain. These include the native Alpine Gentian (G. nivalis), Marsh Gentian (G. pneumonanthe) and Spring Gentian (G. verna).

Alpine Gentian (G. nivalis) and Spring Gentian (G. verna) are protected under Schedule 8 of the Wildlife and Countryside Act, 1981.

Spencer (1972b: 95) recorded Chromatomyia gentianae (as Phytomyza) on Blackstonia perfoliata and Centaurium erythrae (as minus). However, he later (Spencer, 1990: 396-7) recognised that specimens on Blackstonia perfoliata and specimens on Centaurium erythrae represented two different new species, which he described as Chromatomyia blackstoniae and Chromatomyia centaurii respectively.

Chromatomyia gentianae is not a British species. It is recorded elsewhere on Gentiana and Gentianella.

Elsewhere the agromyzids Liriomyza bryoniae and Liriomyza huidobrensis are recorded mining Gentiana.

One non-Diptera miner is recorded on Gentiana in Britain (see below).

A key to the European miners, based on characteristics of the mines, immature stages and where relevant the larval cases, recorded on Gentiana and Gentianella is provided in Bladmineerders van Europa. This includes Chromatomyia gentianae, Liriomyza amarellae and Stenoptilia zophodactylus.

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

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: Initially the larva mines a basal leaf, subsequently feeding in flower buds (which turn yellow), opened flowers and foliage (UKMoths). Full depth irregular blotch that may occupy an entire leaf. Frass in numerous, dispersed, brown grains. Some larvae remain in the mine until shortly before pupation, others leave the mine in an early stage and feed externally on the flower buds and developing fruits (Bladmineerders van Europa).

Mine of Stenoptilia zophodactylus on Gentiana sp. Image: Willem Ellis (Bladmineerders van Europa)

Recorded on Blackstonia, Centaurium and Gentiana in Britain and Blackstonia, Centaurium, Gentiana and Gentianella elsewhere. Widely distributed in southern Britain and continental Europe.

Stenoptilia zophodactylus (Duponchel, 1840) [Lepidoptera: Pterophoridae]