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

1# >Leaf / Stem-miner: In leaf stems and fronds (Ackland in Chandler, 1978: 227).

On ? Matteucia and ? Pteridium in Britain. Also on Athyrium elsewhere. Widespread in Britain and continental Europe

Chirosia cinerosa (Zetterstedt, 1845) [Diptera: Anthomyiidae].

1a > Leaf- and stem-mine: Mine in the lowest part of the petiole, not in the pinnulae-bearing part of the rachis. Often several larvae together. Mined leaves are stunted, often incompletely rolled out. Puparium in the mine or in the ground. See de Meijere (1911a) and Brown and McGavin (1982) for details of the biology.

On ? Pteridium in Britain. Widespread in Britain and continental Europe

Chirosia crassiseta Stein, 1908 [Diptera: Anthomyiidae].

1b > Stem-miner: Oviposition normally on one of the lower secondary pinnulae. The larva enters a vein and from there descends as a borer in the rachis. Often several larvae together. Attacked leaves can be recognised because the leaf is stunted, often remaining partly unfolded. Pupation in the mine or in the ground. See Brown and McGavin (1982) for details of the biology.

On ? Pteridium in Britain and elsewhere. Widespread and not uncommon in Britain. Widespread in continental Europe

Chirosia albitarsis (Zetterstedt, 1845) [Diptera: Anthomyiidae].

1c > Leaf-miner: The larva mines the lower surface of rachis, close to the lesf tip. The upper surface is left intact, resulting in growth disturbance that causes the leaf tip to strongly curl downwards. Larva generally solitary. Pupation within the roll.

The miner causes the pinna tip to curl downwards.

On Pteridium aquilinum in Britain and elsewhere and in addition Asplenium and Dryopteris eslewhere. Common and widely distributed in Britain. Also recorded in the Republic of Ireland. Widespread in continental Europe. Also recorded East Palaearctic Region.

Chirosia grossicauda (Strobl, 1899) [Diptera: Anthomyiidae].

1d > Leaf-miner: Large full depth blotch, covering the entire distal part of a pinnula. The mine begins near the top, where an elliptic egg shell is attached to the underside of the rachis. Larva solitary. The mine contains much frass.

An upperside blotch at the tip of a pinna lobe.

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].

1e > Leaf-miner: Ovipisition on the upper part of the rachis of an unrolling leaf. The larva bores into the rachis, causing the distal part of the leaf to become stunted and finally necrotic. Often several larvae in a mine. Pupation outside the mine (Brown and McGavin, 1982a).

Hosts in Britain unknown. On Pteridium elsewhere. Widespread in Britain. Recorded also inFinland, Germany, Italian mainland, Russia - North and Sweden

1f > Leaf-miner: Larva forming short linear mine in single section of a frond. Pupation external (Spencer, 1972b: 58).

Large, very transparant blotch, with primary and secondary feeding lines. In the centre a concentration of black frass. Mines can coalesce, and then contain several larvae. At the start of the mine, at the leaf underside, a white egg shell. However, the larva can leave its mine and restart elsewehere, therefore mines without an egg shell may occur as well.

A small marginal upper surface gallery in a single section of frond.

On Pteridium aquilinum and Polypodium vulgare in Britain. Also Asplenium elsewhere. Widespread in Britain. Also recorded in the Republic of Ireland. Widespread throughout Europe.

Phytoliriomyza hilarella (Zetterstedt, 1848) [Diptera: Agromyzidae].

1g > Leaf-miner: A short linear mine at edge of frond segment. Pupation external. Mines practically identical to those of P. hilerella which may be distinguished from P. pteridii by the male genitalia. Puparium brownish-orange

On Pteridium aquilinum in Britain and elsewhere. Included in Robbins (1991: 20) from the 'north' in Britain. Also recorded in the Republic of Ireland. Widespread in continental Europe.

Phytoliriomyza pteridii Spencer, 1973 [Diptera: Agromyzidae].

1h > 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.

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

Psychoides verhuella Bruand, 1853 [Lepidoptera: Tineidae].