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


CONVOLVULUS. Bindweeds and Convolvuluses. [Convolvulaceae]

Field Bindweed (C. arvensis) is the only native species of Convolvulus recorded in Britain. Introduced species include Austraian Bindweed (C. erubicens), Ground Blue-convolvulus (C. sabatius), Mallowed-leaved Bindweed (C. althaeoides), Small Blue-convolvulus (C. siculus) and Tricolor Convolvulus (C. tricolor).

Four British miners are recorded on Convolvulus.

The agromyzid Melanagromyza albocilia is recorded boring the stems of Convolvulus elsewhere.

A key to the European miners recorded on Convolvulus including Calystegia is provided in Bladmineerders van Europa.

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

1a > Leaf miner: Blotch mine. Broad corridor, widening into a large transparant blotch with 1 or several, proportionally very large larvae that quickly completely mine out a leaf, then move to another leaf. At the start of the first mine at the leaf underside 1 or more oval egg shells. Pupation outside the mine.

Forms large blotches on leaves.

On Convolvulus and Fallopia in Britain and Fallopia and possibly Persicaria elsewhere. Uncommon in England - Warwick, Oxford, Hants and West Kent. Widespread in continental Europe.

Pegomya setaria (Meigen, 1826) [Diptera: Anthomyiidae].

1b > 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.

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

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

1c > Leaf miner: At first it makes a narrow gallery lined with frass, but subsequently it makes a series of large translucent yellowish brown blotch mines from which all frass is ejected. It also constructs under the leaf an 'aerial' network of silk threads in which it moves around and rests clear of the leaf surface when not feeding. The mine begins at an egg shell that almost invariably is placed on (not next to) the midrib. The egg is oval, not globular, like in the Nepticulidae. Here a narrow tortuous corridor of some 30 mm begins, with a central frass line, reminding of a Stigmella mine, that often cuts off part of the leaf, causing it to die. Then the larva leaves this mine and begins to make a series of full depth full depth mines (not necessarily on the same leaf). The larva is larger than the mine, and protrudes from it with the rear part of its body. The openings to all these mines are in the lower epidermis. Under the leaf an irregular spinning develops, in which frass grains are trapped. Pupation outside the leaf. The pupa is attached to a leaf without a cocoon. It has a dorsal keel and a pronounced facial beak.

On Calystegia, Convolvulus and Ipomoea in Britain and elsewhere. Widespread in southern England and Wales. Also recorded in the Republic of Ireland. Widespread in continental Europe.

Bedellia somnulentella (Zeller, 1847) [Lepidoptera: Bedellidae].

1d > 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 plant families, but not yet on Convolvulus, in Britain. On numerous genera and species of plant families including Convolvulus elsewhere. Widespread in Britain and continental Europe. Also recorded from the Channel Is.

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

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