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

 

AGRIMONIA. Agrimony. [Rosaceae]


Two species of Agrimonia are recorded in Britain, the native Agrimony (A. eupatoria L.) and Fragrant Agrimony (A. procera Wallr.). The BSBI provide a downloadable plant crib for Agrimonia.

Fifteen British miners are recorded on Agrimonia.

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

 

Fragrant agrimony - Agrimonia odorata. Image: © Brian Pitkin
Fragrant agrimony
Agrimonia procera



Key for the identification of the known mines of British
Diptera recorded on Agrimonia


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).

See Key to non-Diptera.


1a > 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 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].

1b > Leaf-miner: A long linear mine, never widening into a blotch at end (Spencer, 1976: 107-8, fig. 167).

Long upper-surface corridor. Many straight stretches, often along the midrib. Frass in discrete grains, here and there in thread fragments, but never in pearl strings. Pupation outside the mine.

A long straight mine, which is sometimes branched. Found in the upper leaf surface.

On Filipendula, Potentilla, Rubus and Sanguisorba, but not yet on Agrimonia, in Britain and Filipendula, Potentilla, Rubus and Sanguisorba elsewhere. Currently known in Britain only from Warwick and Mid-west York. Also recorded in the Republic of Ireland and continental Europe.

Agromyza filipendulae Spencer, 1976 [Diptera: Agromyzidae].

1c > Leaf-miner: A distinctive mine primarily above mid-rib, with irregular short lateral offshoots into leaf blade. Pupation external (Spencer, 1972: 51 (fig. 172), 55; Spencer, 1976: 270, 271 (fig. 486)).

Branched, whitish, upper-surface corridor; main axis overlying the midrib; side branches overlying the main lateral veins. (In Campanula and Phyteuma the mine is much less branched, sometimes nothing more than a corridor on top of the midrib). Frass in rather long strings. Usually the mines begins as a long and narrow, shallow, tortuous lower-surface corridor that ends upon the midrib but otherwise is not associated with the leaf venation. Often this initial corridor is filled with callus, and then even less conspicuous. Pupation outside the mine.

A linear mine on the upper surface, usually following the midrib and showing side branches along the veins. The frass is in strings.

Liriomyza strigata larva,  lateral
Liriomyza strigata larva, lateral
Image: © Willem Ellis (Bladmineerders van Europa)

Polyphagous. On more than 40 host genera in 15 families, but not yet on Agrimonia, in Britain. On Agrimonia elsewhere. Widespread throughout Britain. Also recorded in the Republic of Ireland. Widespread in continental Europe.

Liriomyza strigata (Meigen, 1830) [Diptera: Agromyzidae].



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


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 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 > 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. Mine does not contain frass - Coleophora species

2

1b > 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.

3

2a > Leaf-miner and case-bearer: In addition to the small hole where the case was attached there is often a larger hole where the larva has cut a piece of leaf epidermis to create its case. No frass in mine.

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 Agrimonia, Betula, Crataegus, Filipendula ulmaria, Fragaria vesca, Geum, Helianthemum nummularium, Potentilla, Prunus spinosa, Rosa, Rubus caesius, Rosa fruticosus and Salix cinerea 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: In addition to the small hole where the case was attached there is often a larger hole where the larva has cut a piece of leaf epidermis to create its case. No frass in mine.

The larva feeds on a wide range of trees, shrubs and herbs, favouring Rosaceae, but not exclusively. The fully developed cased larva may be found active in October and again, after winter diapause, in April. Cases, about 6 mm, of diapausing larvae may be found through winter, fixed to a tree or fence post. The dorsal surface of the case is usually covered in leaf fragments, but they can sometimes be worn off almost smooth. The ventral surface is swollen at the middle and has a keel, which usually bends upwards at the posterior. The cases of C. ahenella (on Rhamnus, Frangula, Viburnum and Cornus) and C. potentillae (case less swollen, keel not bent up, resting position less prone) are very similar. Brownish lobe case that lies almost flat on the leaf, either on the upper or on the lower side. Case widest about the middle. Ventrally there is a distinct keel. Mouth angle 0°. Full depth mines rather large. The flaps of cuticular tissue that serve to enlarge the case are cut out of the upper epidermis. (contrary to C. ahenella and C. potentillae, that use tissue from the lower epidermis). The removal of these tissue flaps creates holes that are much larger than those that serve as the entrance to the mine.

Coleophora violacea larva,  lateral
Coleophora violacea larva, lateral
Image: © Willem Ellis (Bladmineerders van Europa)

Polyphagous. On numerous genera and species in several plant families, including Agrimonia, in Britain and elsewhere. Widespread in Britain and continental Europe.

Coleophora violaceae (Ström, 1783) [Lepidoptera: Coleophoridae].

3a > Leaf-miner: A long usually narrow winding corridor mine with a central line of frass. Larva not living in a rolled or folded leaf, a tentiform mine or sandwiched between two more or less circular leaf sections in later instars

4

3b > Leaf-miner: Either a blotch or short corridor which becomes a blotch. Larva may live in a rolled or folded leaf, a tentiform mine or sandwiched between two more or less circular leaf sections in later instars

5

4a > Leaf-miner: A slender gallery, leading to blotch. Larva is a pale watery greenish yellowish (whereas S. poterii its yellow).

Egg some place at the underside of the leaf. The first part of the mine is a long, slender corridor, rather straight, often folllowing a vein or the leaf margin. The frass here is black, lying in a very narrow central line. The corridor abruptly widens into a large blotch, where the the frass lies irregularly scattered.

On Agrimonia, Fragaria and Potentilla in Britain and elsewhere. Widespread in Britain and continental Europe.

Stigmella aeneofasciella (Herrich-Schäffer, 1855) [Lepidoptera: Nepticulidae].

4b > Leaf-miner: A long gallery with dispersed frass. Oviposition may be at either side of the leaf, not necessarily close to a vein. The mine is a not very tortuous corridor, not widened in the end. Frass in a broad central line. The mine strongly overlaps with the one of S. splendidissimella.

On Agrimonia, Fragaria, Geum, Potentilla and Rubus in Britain plus Geranium elsewhere. Widespread in Britain and continental Europe.

Stigmella aurella (Fabricius, 1775) [Lepidoptera: Nepticulidae].

4c > Leaf-miner: Egg on the leaf upperside. The mine is an unusually short, not very tortuous corridor with a central line of frass that is irregularly interrupted and takes about 2/3 of the corridor width. Pupation external.

On Rubus fruticosus but not yet on Agromonia in Britain; Agrimonia, Rubus sanctus and Rubus ulmifolius elsewhere. England including Dorset and South Wilts in Britain. Also recorded in the Republic of Ireland and continental Europe.

Stigmella auromarginella (Richardson, 1890) [Lepidoptera: Nepticulidae].

4d > Leaf-miner: A long sinuous gallery with narrow frass-line.

Oviposition generally at the leaf upper side, not especially close to a vein. From there a long and slender corridor starts, with frass usually in a narrow central line. The corridor often crosses itself, but rarely a thick vein (Blladmineerders van Europa).

On Agrimonia, Filipendula, Fragaria, Geum, Potentilla and Rubus in Britain and elsewhere. Widespread in Britain, Ireland and continental Europe.

Stigmella splendidissimella (Herrich-Schäffer, 1855) [Lepidoptera: Nepticulidae].

4e > Leaf-miner: The initial gallery is twisted and can follow the leaf edge. It contains broken linear frass. it then widens to form a blotch or gallery, with scattered frass.

Oviposition on the leaf underside. There starts an initially strongly contorted narrow corridor with a linear interrupted frass line. This is continued in broad corridor or elongated blotch with dispersed frass. Often a number of mines in a leaf. Pupation inside the mine, in a violet to blackish cocoon.

On Agrimonia eupatoria in Britain and Agrimonia eupatoria and Aremonia agrimonioides elsewhere. Recorded in south-east England. Widespread in continental Europe.

Ectoedemia agrimoniae (Frey, 1858) [Lepidoptera: Nepticulidae].

4f > Leaf-miner: A gallery with dispersed frass.

Egg at the underside of the leaf. The first part of the mine is a quite narrow and strongly contorted gallery with grey brown frass. This is followed by an elongate blotch (or broad corridor) that frequently overlaps a part of the earlier mine; here the frass lies scattered throughout the blotch. Pupation external.

On Fragaria and Potentilla sterilis, but not yet on Agrimonia, in Britain plus Agrimonia and Fragaria moschata, Fragaria vesca, Fragaria viridis and Potentilla erecta elsewhere. Widespread in Britain and continental Europe.

Ectoedemia arcuatella (Herrich-Schäffer, 1855) [Lepidoptera: Nepticulidae].

5a > Leaf-miner: Egg well visible, on the upper surface (contrary to Metallus pumilus). The mine is a large, transparant, upper-surface blotch, yellowish green at first, brownish later. Silk is deposited in the mine, but the quantity is too little to influence its colour; also the mine does not contract, like in C. marginea. All frass is ejected through a small opening in the underside of the mine. Pupation takes place after hibernation, within the mine; pupa not in a cocoon.

Coptotriche heinemanni larva,  dorsal
Coptotriche heinemanni larva, dorsal
Image: © Willem Ellis (Bladmineerders van Europa)

On Rubus fruticosus, but not yet on Agrimonia, in Britain plus Agrimonia eupatoria, Agrimonia procera, Rubus caesius, Rubus idaeus and Rubus laciniatus elsewhere. Distribution in Britain unknown. Widespread in continental Europe.

Coptotriche heinemanni (Wocke, 1871) [Lepidoptera: Tischeriidae].

5b > 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 from within the case.

On Agrimonia, Alchemilla, Filipendula, Fragaria, Geum and Rubus 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].

5c > Leaf-miner: Full depth transparent blotch without a clear preceding corridor, quickly and strongly widening from the start. Frass in sausage-shaped granules. Often several leaflets of a composite leaf each have a mine.

The larvae of sawflies have at least six thoracic legs (although they may be reduced or absent), a head capsule and chewing mouthparts with opposable mandibles but no abdominal legs.

Fenella nigrita larva
Fenella nigrita larva
Image: © Willem Ellis (Bladmineerders van Europa)

On Agrimonia, Potentilla and Rubus in Britain plus Aremonia, Filipendula, and Fragaria elsewhere. Widespread in Britain including Surrey and West Cornwall. Widespread in continental Europe.

Fenella nigrita Westwood, 1839 [Hymenoptera: Tenthredinidae].

5d > Leaf-miner: In the first instar the larva mines the leaves, forming short, irregular, blotch-like mines, but in later instars it lives externally, feeding in spun leaves and often twisting those of tender shoots. Larval head light-brown or yellowish brown, edged with black postero-laterally, ocellar area blackish; prothoracic plate black edged with whitish anteriorly; abdomen dull dark green; pinacula distinct, black, sometimes brownish but with black bases to setae; anal plate large, black (Bradley et al., 1973).

Small, full depth mine without a definite shape; little frass. Some silk is deposited in the mine. The larva soon leaves the mine and continues feeding among spun leaves.

Polyphagous. On numerous genera and species of several plant families, but not yet on Agrimonia, in Britain and elsewhere. Widespread in Britain and continental Europe. Also recorded from the Channel Is.

Cnephasia incertana (Treitschke, 1835) [Lepidoptera: Tortricidae].



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