Centaurium [Gentianaceae]

CENTAURIUM. Centaury. [Gentianaceae]

Five species of Centaurium are recorded in Britain. All are native and include Lesser Centaury (C. pulchellum), Slender Centaury (C. tenuiflorum), Common Centaury (C. erythraea), Seaside Centaury (C. littorale) and Perennial Centaury (C. scilloides).

Slender Centaury (C. tenuiflorum) is protected under Schedule 8 of the Wildlife and Countryside Act, 1981.

Seaside Centaury (C. littorale) is protected in Northern Ireland under Schedule 8 of the Wildlife (Northern Ireland) Order, 1985.

Only one Diptera miner, the agromyzid Chromatomyia centaurii, is recorded on Centaurium in Britain.

Elsewhere the polyphagous agromyzids Chromatomyia centaurii and Liromyza bryoniae are recorded mining Centaurium.

One non-Diptera leaf-miner, Stenoptilia zophodactylus, is recorded on Centaurium in Britain (see below).

Elswhere one additional British non-Diptera miner, Orthochaetes insignis, is recorded on Centaurium (see below).

A key to the European miners, based on characteristics of the mines, immature stages and where relevant the larval cases, recorded on Centaurium is provided in Bladmineerders van Europa. This includes Liromyza bryoniae, Chromatomyia gentianae (misidentification), Chromatomyia centaurii, Orthochaetes insignis and Stenoptilia zophodactylus.

Common Centaury
Centaurium erythraea

Key for the identification of the mines of British Diptera recorded on
Centaurium

Note: Diptera larvae may live in a corridor mine, a corridor-blotch mine, or a blotch mine, but never in a case, a rolled or folded leaf, a tentiform mine or sandwiched between two more or less circular leaf sections in later instars. Pupation never in a cocoon. All mining Diptera larvae are leg-less maggots without a head capsule (see examples). They never have thoracic or abdominal legs. They do not have chewing mouthparts, although they do have a characteristic cephalo-pharyngeal skeleton (see examples), usually visible internally through the body wall. The larvae lie on their sides within the mine and use their pick-like mouthparts to feed on plant tissue. In some corridor miners frass may lie in two rows on alternate sides of the mine. In order to vacate the mine the fully grown larva cuts an exit slit, which is usually semi-circular (see Liriomyza huidobrensis video). The pupa is formed within the hardened last larval skin or puparium and as a result sheaths enclosing head appendages, wings and legs are not visible externally (see examples).

1 > Leaf-miner: Linear in first instar, later developing into a blotch which is frequently at base of leaf. Pupation internal. Puparium whitish

On Centaurium erythraea in Britain and elsewhere. Widespread in southern England. Also recorded in the Republic of Ireland and in continental Europe only Germany.

Chromatomyia centaurii Spencer, 1990 [Diptera: Agromyzidae].

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

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).

1a > Leaf-miner: Rather narrow corridor, untidy and sometimes branched, starting from the base of the leaf, in particular the midrib. Sides of the corridor irregularly eaten out, not really parallel. Frass mostly present, and then in a central line. The legless larva is capable of leaving the mine and start a new one elsewhere. These later mines are much broader, and the frass is scattered irregularly. (Bladmineerders van Europa.

Host plants unknown in Britain. Recorded on numerous genera and species in several plant families, including Centaurium, elsewhere. Recorded in southern England. Widespread in continental Europe.

Orthochaetes insignis (Aube, 1863) [Coleoptera: Curculionidae]

1b > 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]


	Last updated 04-Feb-2012 Brian Pitkin