Dryopteris [Dryopteridaceae]

DRYOPTERIS. Buckler ferns. [Dryopteridaceae]

Ten species of Dryopteris, are recorded in Britain. These include the native Broad Buckler-fern (D. dilatata), Crested Buckler-fern (D. cristata), Hay-scented Buckler-fern (D. aemula), Male-fern agg., (D. filix-mas), Mountain Male-fern (D. oreades), Narrow Buckler-fern (D. carthusiana), Northern Buckler-fern (D. expansa), Rigid Buckler-fern (D. submontana), Scaly Buckler-fern (D. remota) and Scaly Male-fern (D. affinis).

Only one Diptera miner, the anthomyiid Chirosia histricina, is recorded mining Dryopteris.

Elsewhere the anthomyiids Chirosia betuleti, Chirosia grossicauda and Chirosia histricina are recorded mining Dryopteris.

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

Elesewhere one additional British non-Diptera miner is recorded on Dryopteris (see below).

A key to the European miners, based on characteristics of the mines, immature stages and where relevant the larval cases, recorded on Dryopteris is provided in Bladmineerders van Europa. This includes Chirosia betuleti, Chirosia histricina and Heptamelus ochroleucus but not Psychoides filicivora or Chirosia grossicauda.

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

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: Mine in the frond, not its rolled apex. Mine on upperside. Even if deep still greenish in transmitted light. Mine very large and broad, usually extended to full depth of a single leaf section, The frass lies in a single almost unbroken fine, black line, parallel to the leaf margins.

On Pteridium and Dryopteris in Britain and continental Europe and additional other genera of ferns elsewhere. Widespread in Britain and continental Europe. Also recorded in East Palaearctic and Near East.

Chirosia histricina Rondani, 1866 [Diptera: Anthomyiidae].

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

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: Larvae usually feed on the underside of a fern frond under an untidy mass of sporangia, but on occasion enter the leaf to make an extensive irregular blotch mine (British leafminers). Usually the larva lives free under the leaf, under an inrregular mass of spun soredia and frass. The larva feeds on the sori, and larva betrays its presence as a sorus on an unusual place. Sometimes also elongate full depth blotches are made (Bladmineerders van Europa).

Recorded on Asplenium, Phyllitis, Polystichum and Dryopteris in Britain and Asplenium, Ceterach, Phyllitis, Polystichum and Dryopteris elsewhere. Widespread in southern England and Wales. Initially occurred mainly near coasts, but it is increasingly recorded inland. Outside of Britain and Northern Ireland, only recorded in Madeira.

Psychoides filicivora (Meyrick, 1937) [Lepidoptera: Tineidae]

1b > Leaf-miner: Full-depth corridor or blotch, often positioned along the leaf margin. In the first part much, brown-black, fine-grained frass, later parts of the mine almost free from frass. After hibernation the larva lives free in an untidy case of silk, covered with remants of sori (Bladmineerders van Europa).

Recorded on Asplenium, Ceterach, Phyllitis and Polystichum, but not yet on Dryopteris, in Britain and Asplenium, Ceterach, Phyllitis, Pteridium and Dryopteris elsewhere. Widespread in Britain and continental Europe.

Psychoides verhuella Bruand, 1853 [Lepidoptera: Tineidae]


	Last updated 04-Feb-2012 Brian Pitkin