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DAUCUS. Carrots. [Apiaceae] |
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Nine species of Daucus are recorded in Britain. These include the native Carrot (D. carota), Sea Carrot (D. carota gummifer) and Wild Carrot (D. carota carota). Two Diptera miners, the agromyzids Phytomyza chaerophylli and Napomyza carotae, are recorded on Daucus in Britain. The agromyzid Phytomyza chaerophylli is also recorded on Chaerophyllum, Conopodium, Torilis, and possibly Sison in Britain. Elsewhere the agromyzids Chromatomyia horticola, Chromatomyia syngenesiae, Liriomyza huidobrensis, Liriomyza sativae, Liriomyza trifolii, Phytomyza chaerophylli, Phytomyza heracleana, Napomyza carotae and the tephritid Euleia heraclei are recorded mining Daucus. Two non-Diptera miners are recorded on Daucus in Britain (see below). Elsewhere one additional non-Diptera miner is recorded on Daucus. A key to the European miners, based on characteristics of the mines, immature stages and where relevant the larval cases, recorded on Daucus is provided in Bladmineerders van Europa. This includes Chromatomyia horticola, Napomyza carotae, Phytomyza chaerophylli, Phytomyza ferulae, Phytomyza heracleana, Phytomyza mylini, Agonopterix purpurea, Agonopterix rotundella, Cnephasia asseclana, Cnephasia incertana, Epermenia chaerophyllella, Epermenia aequidentellus but not Chromatomyia syngenesiae, Liriomyza huidobrensis, Liriomyza sativae, Liriomyza trifolii or Euleia heraclei. N.B. The key to mines below includes mines recorded on Chaerophyllum, Conopodium, Daucus, Sison and Torilis (Apiaceae). |
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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). 1a > Leaf-miner: A short, narrow, linear mine, generally closely following margin of leaf segment; in very small sections of a leaf producing a secondary blotch. Puparium shining black
Phytomyza chaerophylli Kaltenbach, 1856 [Diptera: Agromyzidae]. 1b > Leaf-miner: Oviposition as a rule in the stem, only occasionally in a leaf. In the latter case the larva makes an upper-surface corridor that ends in a thick vein. From there it descends, through petiole and stem, down to the root. Here the pupation takes place
Napomyza carotae Spencer, 1966 [Diptera: Agromyzidae]. |
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Key for the identification of the mines of British
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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).
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1a > 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 (Bladmineerders van Europa). Recorded on numerous genera and species of plant families, but not yet on Daucus, in Britain. Recorded on numerous genera and species of plant families including Daucus elsewhere. Widespread in Britain and continental Europe. Also recorded from the Channel Is. Cnephasia incertana (Treitschke, 1835) [Lepidoptera: Tortricidae]
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1b > Leaf-miner: Young larvae make small, full depth blotch mines, almost without frass. Older larva live externally on the plant under a light web (Bladmineerders van Europa). Initially forms a small blotch mine and may later feed in a slight web. In coastal areas may continue mining throughout the larval stage (British leafminers). |
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Epermenia aequidentellus (Hofmann, 1867) [Lepidoptera: Epermeniidae]
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1c > Leaf-miner: The larvae are often gregarious and feed on the underside of the leaf causing a 'windowing' effect as they eat the mesophyll and lower epidermis. This effect can be seen from the top of the leaf as it discolours (British leafminers). Short, small, irregular, sometimes widened corridor. Mostly a number in a leaf, concentrated in the axils of the midrib and the primary side veins. Each larva makes a number of mines. Often the larva protrudes with its rear end out of the mine, causing most frass to be ejected. While moving, at the leaf underside, silken threads are produced, in wich grains of frass may be trapped. Older larvae live free and cause window feeding, often in a group under a light spinning (Bladmineerders van Europa).
Epermenia chaerophyllella (Goeze, 1783) [Lepidoptera: Epermeniidae] |
| Last updated 04-Feb-2012 Brian Pitkin |  |
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