The leaf and stem mines of British flies and other insects

(Coleoptera, Diptera, Hymenoptera and Lepidoptera)

by Brian Pitkin, Willem Ellis, Colin Plant and Rob Edmunds


SPIRAEA. Brideworts and Spiraeas. [Rosaceae]

Twelve species of Spiraea are recorded in Britain. All are introduced. The BSBI provide a downloadable plant crib for Spiraea.

Six British miners are recorded on Spiraea.

A key to the European miners recorded on Spiraea is provided in Bladmineerders van Europa.

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

1b > Leaf-miner and case-bearer: The larva lives outside the mine, protected by a case, and feeds on the underlying plant tissues via a hole cut in the epidermis. From that point it eats away as much leaf tissue as it can reach without fully entering the mine. Mine does not contain frass (Coleophora species)


1d > Leaf-miner, but not a case-bearer: The larva lives mainly inside the mine. Mine usually contains frass. In later instars the larva may live sandwiched between two more or less circular sections cut from the leaf.

2a > Leaf-miner and case-bearer: The case resembles that of C. violacea, but does not lie so flat again the leaf as this species (having a mouth angle of 30 to 50°). C. violacea also has a case which bulges in the middle, whereas in C. potentillae the case tapers towards the posterior. Immediately after emergence the larva makes a full depth, quickly widening, corridor, with frass as small grains in a broad central band. Finally results a blotch of 2 x 5 mm, from which the youth case is cut. The fully developed case is a hairy, greyish brown to silver grey lobe case of about 1 cm long, with a clearly laterally compressed end; the mouth angle is about 90°. The case is difficult to separate from that of C. ochripennella.

On Betula, Agrimonia, Crataegus, Filipendula ulmaria, Fragaria vesca, Geum, Helianthemum nummularium, Potentilla, Prunus spinosa, Rosa, Rubus caesius, Rosa fruticosus and Salix cinerea, but not yet on Spiraea, in Britain plus Malus sylvestris, Ribes, Sanguisorba and Spiraea elsewhere. Widespread in Britain and in continental Europe.

Coleophora potentillae (Elisha, 1885) [Lepidoptera: Coleophoridae].

2b > Leaf-miner and case-bearer: The species spends two years as a larva, the first one-and-a-half years in a small pistol-case, and in the second spring building a long straight case which is dark brown and rather distinctive. The lava lives from autumn until summer next year. In autumn a composite leaf case is made, shaped like the handle of a walking stick. Early in the following spring a tubular leaf case is made that in the end is rather large (10 mm) and is positioned vertically on the leaf; mouth angle 90°.

On Cotoneaster, Crataegus, Malus, Prunus, Pyrus and Sorbus, but not yet on Spiraea, in Britain and Amelanchier, Chaenomeles, Cotoneaster, Crataegus, Cydonia, Malus, Prunus, Pyrus, Sorbus and Spiraea elsewhere. Occurs locally in the south east of England and the Channel Is. Widespread in continental Europe.

Coleophora hemerobiella (Scopoli, 1763) [Lepidoptera: Coleophoridae]

2c > Leaf-miner and case-bearer: The larva feeds by inserting its head into small mines it creates on the leaves of birch, elm, alder, or hazel. Occasionally it is found feeding on other trees, or on herbaceous plants onto which it has accidentally Fallén. It forms two cases during its larval life. The first case is initially curved, smooth, laterally compressed with a bivalved anal opening, and about 2 mm long in September. During October it feeds, and adds a few rough collars of larval material around the oral opening. After hibernation, it feeds again in April and early May, adding more protruding collars until they equal or exceed the original smooth part of the case. At the same time, it expands the case girth by the creation of a silk gusset ventrally. The second case, 6 or 7 mm long, is formed in May, leaving the vacated first case attached to its last feeding mine. The new case is tubular with a trivalved crimp at the anal opening. The dorsum is formed from the edge of the leaf from which the case was cut. This results in a more or less serrated dorsal keel, depending on the plant species and the individual piece of leaf used. Considerable variation in the degree of serration can be found, even among specimens off the same tree. The case colour varies with food plant, from yellowish brown on birch, darkening through elm and hazel to dark brown on alder. The strongly curved young case is is a composite leaf case, the adult case is a tubular leaf case. The adult case is bivalved, about 7 mm in length; the mouth angle is around 30°. The case is straw coloured and almost always has a toothed dorsal keel (remnant of the margin of the leaf from which the case was cut). Neither larvae or cases of C. coracipennella, prunifoliae, serratella and spinella can be separated; from serratella.

On Alnus, Betula, Corylus, Ulmus and Sorbus, but not yet on Spiraea, in Britain plus Carpinus, Mespilus, Ostrya, Hippophae, Ribes, Myrica, Forsythia, Amelanchier, Chaenomeles, Cotoneaster, Crataegus, Cydonia, Eriobotrya, Malus, Prunus, Sorbus, Spiraea, Populus and Salix elsewhere. This is probably the commonest species of British coleophorid, and is found throughout the British Isles. Widespread in continental Europe.

Coleophora serratella (Linnaeus 1761) [Lepidoptera: Coleophoridae].

3a > Leaf-miner: Initially a linear mine which later develops into a conspicuous blotch; frass in two rows in linear section, scattered irregularly in the blotch (Spencer, 1976: 134-5, fig. 237, as potentillae).

Corridor, gradually and considerably widening towards the end. Frass in two rows in the corridor part, further up dispersed irregularly. Pupation outside the mine.

A short broad upper surface corridor leading to a long blotch between veins.

On Agrimonia, Filipendula, Fragaria, Geum, Potentilla, Rubus and Sanguisorba, but not yet on Spiraea, in Britain. On additional Rosaceae elsewhere. Common and widespread throughout Britain. Also recorded in the Republic of Ireland, Europe, Japan, U.S.A. and Canada.

Agromyza idaeiana (Hardy, 1853) [Diptera: Agromyzidae].

3b > Leaf-miner: The mine is in the upper epidermis of a leaf, usually over midrib or vein. The mine is at first silvery, later with brown speckling. Silvery, upper-surface, epidermal tentiform mine, centered over the midrib or a heavy lateral vein. Unlike P. leucographella, with which this species shares some host plants, the upper epidermis looks dirty by the presence of numerous fine black-brown specks of frass. The epidermis remains without folds until the mine becomes strongly contrated. Young mines look like a streak of silver on top of a vein.

On Betula, Crataegus, Malus, Pyrus and Sorbus, but not yet on Spiraea, in Britain and Betula, Fagus, Amelanchier, Chaenomeles, Cotoneaster, Crataegus, Cydonia, Malus, Mespilus, Prunus, Pyrus, Sorbus and Spiraea elsewhere.

Phyllonorycter corylifoliella (Hübner, 1796) [Lepidoptera: Gracillariidae].

3c > Leaf-miner: Small (less than 1 cm), full depth blotch, transparent when fresh, starting at the leaf margin, usually near the leaf tip; frass in scattered grains. The larva makes an elliptic double sided excision to form a case. Subsequently, it continues feeding within the case.

On Agrimonia, Alchemilla, Filipendula, Fragaria, Geum and Rubus, but not yet on Spiraea, in Britain. On Achillea, Agrimonia, Alchemilla, Filipendula, Fragaria, Geum, Potentilla, Rubus and Spiraea elsewhere. Distributed throughout much of Britain. Widespread in continental Europe.

Incurvaria praelatella (Denis & Schiffermüller, 1775) [Lepidoptera: Incurvariidae].

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