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

  

Cerodontha incisa (Meigen, 1830)
[Diptera: Agromyzidae]

Agromyza incisa Meigen, 1830. Syst. Beschr. 6: 182
Cerodontha (Poemyza) incisa (Meigen, 1830); Spencer, 1990. Host specialization in the World Agromyzidae (Diptera): 354, 355, 356, 357, 367, 368 (fig. 1379), 369
Cerodontha incisa (Meigen, 1830); Ellis. Bladmineerders van Europa.

Leaf-miner: Broad elongated mine; the form is dependent of the leaf form of the host plant. Frass green. Usually a number of larvae together in a mine. Pupation in the mine (Bladmineerders van Europa).

Larva: The larvae of flies 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 larva is described by Nowakowski (1973), Dempewolf (2001: 117) and illustrated in Bladmineerders van Europa.

Cerodontha incisa larva, dorsal
Cerodontha incisa larva, dorsal
Image: © Willem Ellis (Bladmineerders van Europa)

Puparium: The puparia of flies are 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).

Shining, metallic blue-black, deeply segmented, loosely attached by silk; posterior spiracles on conspicuous projections, each with 3 rounded bulbs (Bladmineerders van Europa). Nowakowski (1973) and Dempewolf (2001) give details of the puparium.

The larvae of C. incisa and C. pygmaea are easily discriminated. The oposite hold for their pupariumriua, which is unfortunate because they are found frequently (much more often then the larvae) and because they are quite conspicuous. They are deep black with a strong violet or blue metallic shine; they are lying in the mine, not in puparial chamber, but anchored to the inner wall of the mine by means of a thread. Often several pupariria are found together, and then frequently the anchor wires are fused near the point where they are attached to the plan (Bladmineerders van Europa).

De Meijere (1928) and Hering (1957a) state that the distal margin of the common base of the rear pupariria is straight or convex in incisa, concave in pygmaea. This must be related to the size of the warts at either side of the rear spiracula, small in incisa, large in pygmaea. In practice, however, I find this character difficult to use. A second character invoked by them is that the intersegmental constrictions in incisa are roughened by tiny scalelike irregularities, while those in pygmaea have minute transverse corrugations. I have the impression that this is not reliable (Bladmineerders van Europa).

Cerodontha incisa or Cerodontha pygmaea puparium
Cerodontha incisa or Cerodontha pygmaea puparium
Image: © Willem Ellis (Bladmineerders van Europa)

Comments: Festuca arundinacea is treated as Schedonorus arundinacea (Tall Fescue); Festuca gigantea is treated as Schedonorus gigantea (Giant Fescue) and Festuca pratensis is treated as Schedonorus pratensis (Meadow Fescue) by Stace (2010).

Hosts in Great Britain and Ireland:

Poaceae        
Bromopsis ramosus Hairy-brome British Wild Flowers by John Somerville et al. Pitkin & Plant
Bromopsis ramosus Hairy-brome British Wild Flowers by John Somerville et al. Robbins, 1991:136
Calamagrostis epigejos Wood Small-reed British Wild Flowers by John Somerville et al. Spencer, 1972b:
Dactylis       Robbins, 1991: 136
Elymus       Pitkin & Plant
Elymus repens Common couch British Wild Flowers by John Somerville et al. Robbins, 1991: 136
Phalaris arundinacea Reed Canary-grass British Wild Flowers by John Somerville et al. Spencer, 1972b: 104

Hosts elsewhere:

Poaceae        
Agrostis       Spencer, 1990: 354
Agrostis capillaris Common Bent British Wild Flowers by John Somerville et al. Bladmineerders van Europa
Agrostis stolonifera Creeping Bent British Wild Flowers by John Somerville et al. Bladmineerders van Europa
Alopecurus       Spencer, 1990: 354
Alopecurus pratensis Meadow Foxtail British Wild Flowers by John Somerville et al. Bladmineerders van Europa
Ammophila       Spencer, 1990: 354
Ammophila arenaria Marram   Bladmineerders van Europa
Anthoxanthum       Spencer, 1990: 354
Anthoxanthum odoratum Sweet Vernal-grass British Wild Flowers by John Somerville et al. Bladmineerders van Europa
Avena       Spencer, 1990: 354
Avena sativa Oat   Bladmineerders van Europa
Briza       Spencer, 1990: 355
Bromopsis ramosa Hairy-brome British Wild Flowers by John Somerville et al. Bladmineerders van Europa
Bromus       Spencer, 1990: 355
Bromus arvensis Field Brome   Spencer, 1972b: 104
Bromus arvensis Field Brome   Bladmineerders van Europa
Bromus erectus Upright Brome   Bladmineerders van Europa
Bromus inermis Hungarian Brome   Bladmineerders van Europa
Bromus hordeaceus Soft Brome British Wild Flowers by John Somerville et al.

Bladmineerders van Europa, as mollis
Bromus tectorum Drooping Brome   Bladmineerders van Europa
Calamagrostis       Spencer, 1990: 354
Calamagrostis       Spencer, 1976: 196
Calamagrostis arundinacea     Bladmineerders van Europa
Calamagrostis canescens Purple Small-reed   Bladmineerders van Europa
Calamagrostis epigejos Wood Small-reed British Wild Flowers by John Somerville et al. Bladmineerders van Europa
Calamagrostis epigejos Wood Small-reed British Wild Flowers by John Somerville et al. Spencer, 1972b: 104
Calammophila baltica Purple Marram   Bladmineerders van Europa
Dactylis       Spencer, 1990: 355
Dactylis glomerata Cock's-foot British Wild Flowers by John Somerville et al. Bladmineerders van Europa
Digitaria       Bladmineerders van Europa
Echinochloa crus-galli Cockspur British Wild Flowers by John Somerville et al. Bladmineerders van Europa
Elymus repens Common couch British Wild Flowers by John Somerville et al. Spencer, 1990: 356
Elymus repens Common couch British Wild Flowers by John Somerville et al. Bladmineerders van Europa
Elytrigia       Spencer, 1990: 356
Elytrigia       Spencer, 1976: 196
Festuca       Spencer, 1990: 355
Festuca       Spencer, 1976: 196
Festuca arundinacea Tall Fescue British Wild Flowers by John Somerville et al. Bladmineerders van Europa
Festuca gigantea Giant Fescue British Wild Flowers by John Somerville et al. Bladmineerders van Europa
Festuca pratensis Meadow Fescue   Bladmineerders van Europa
Hierochloe australis     Bladmineerders van Europa
Holcus lanatus Yorkshire-fog British Wild Flowers by John Somerville et al. Bladmineerders van Europa
Holcus lanatus Yorkshire-fog British Wild Flowers by John Somerville et al. Spencer, 1990: 354
Holcus mollis Creeping Soft-grass   Bladmineerders van Europa
Hordeum       Spencer, 1990: 356
Hordeum vulgare Six-rowed Barley   Bladmineerders van Europa
Leymus arenarius Lime-grass British Wild Flowers by John Somerville et al. Bladmineerders van Europa
Lolium       Spencer, 1990: 355
Lolium multiflorum Italian Rye-grass British Wild Flowers by John Somerville et al. Bladmineerders van Europa
Lolium perenne Perennial Rye-grass British Wild Flowers by John Somerville et al. Bladmineerders van Europa
Lolium perenne Perennial Rye-grass British Wild Flowers by John Somerville et al. Spencer, 1972b: 104
Melica       Bladmineerders van Europa
Milium       Spencer, 1990: 356
Molinia caerulea Purple Moor-grass British Wild Flowers by John Somerville et al. Bladmineerders van Europa
Phalaris       Spencer, 1990: 355
Phalaris       Spencer, 1976: 196
Phalaris arundinacea Reed Canary-grass British Wild Flowers by John Somerville et al. Dempewolf, 2001: 117
Phalaris arundinacea Reed Canary-grass British Wild Flowers by John Somerville et al. Bladmineerders van Europa
Phleum pratense Timothy British Wild Flowers by John Somerville et al. Bladmineerders van Europa
Phragmites       Spencer, 1990: 356
Phragmites australis Common Reed British Wild Flowers by John Somerville et al. Spencer, 1972b: 104
Phragmites australis Common Reed British Wild Flowers by John Somerville et al. Bladmineerders van Europa
Poa       Spencer, 1990: 355
Poa trivialis Rough Meadow-grass British Wild Flowers by John Somerville et al. Bladmineerders van Europa
Secale       Spencer, 1990: 356
Secale cereale Rye   Bladmineerders van Europa
Setaria       Bladmineerders van Europa
Trisetum       Spencer, 1990: 355
Triticum       Spencer, 1990: 356
Triticum aestivum Bread Wheat   Bladmineerders van Europa
Zea mays Maize   Bladmineerders van Europa

Time of year - mines: June-September, sometimes also May and October (Bladmineerders van Europa).

Time of year - adults: Currently unknown.

Distribution in Great Britain and Ireland: Widespread in Britain including London (Hampstead), Middlesex (Scratch Wood), Oxfordshire (Oxford), Suffolk (Chillesford), Dunbartonshire (Bonhill) (Spencer, 1972b: 104), Warwickshire (Coventry, Holbrooks) (Robbins, 1991: 136); Cambridgeshire, East Norfolk, Elgin, Pembrokeshire and South-west Yorkshire (NBN Atlas).

Also recorded in the Republic of Ireland: Co. Clare (Burren) (Spencer, 1972b: 104).

Distribution elsewhere: Widespread and common in Europe (Spencer, 1990: 367) including Denmark, Finland, Norway, Sweden (Spencer, 1976: 196), The Netherlands, Luxembourg (Bladmineerders van Europa), Belgium (Scheirs and de Bruyn, 1992), Germany (Spencer, 1976: 554), Austria, Corsica, Czech Republic, Estonia, Hungary, Iceland, Italian mainland, Latvia, Lithuania, Poland, Romania, Slovakia, Spanish mainland and Yugoslavia (Fauna Europaea).

Also recorded in Japan (as okazakii) (Spencer, 1990: 367), U.S.A. and Canada (Spencer, 1969a: 128; Dempewolf, 2001: 117).

NBN Atlas links to known host species:

Agrostis capillaris, Agrostis stolonifera, Alopecurus pratensis, Ammophila arenaria, Anthoxanthum odoratum, Avena sativa, Bromopsis ramosa, Bromus arvensis, Bromus erectus, Bromus hordeaceus, Bromus inermis, Bromus tectorum, Calamagrostis canescens, Calamagrostis epigejos, Calammophila baltica, Dactylis glomerata, Echinochloa crus-galli, Elymus repens, Festuca arundinacea (= Schedonorus arundinacea), Festuca gigantea (= Schedonorus gigantea), Festuca pratensis (= Schedonorus pratensis), Holcus lanatus, Holcus mollis, Hordeum vulgare, Leymus arenarius, Lolium multiflorum, Lolium perenne, Molinia caerulea, Phalaris arundinacea, Phleum pratense, Phragmites australis, Poa trivialis, Secale cereale, Triticum aestivum, Zea mays

British and Irish Parasitoids in Britain and elsewhere:

Chalcidoidea   
Chrysocharis polyzo (Walker, 1839) Eulophidae: Entedoninae
Chrysocharis viridis (Nees, 1934) Eulophidae: Entedoninae
Pediobius metallicus (Nees, 1834) Eulophidae: Entedoninae
Pnigalio soemius (Walker, 1839) Eulophidae: Eulophinae
Merismus megapterus Walker, 1833 Pteromalidae: Miscogastrinae
Ichneumonoidea - Links to species no longer available  
Chorebus cytherea (Nixon, 1937) Braconidae: Alysiinae
Chorebus difficilis Griffiths, 1968 Braconidae: Alysiinae
Chorebus poemyzae Griffiths, 1968 Braconidae: Alysiinae
Chorebus talaris (Haliday, 1839) Braconidae: Alysiinae
Coloneura stylata Förster, 1862 Braconidae: Alysiinae
Exotela flavicoxa (Thomson, 1895) Braconidae: Alysiinae
Exotela melanocera (Thomson, 1895) Braconidae: Alysiinae
Heterolexis balteata (Thomson, 1895) Braconidae: Alysiinae
Opius ambiguus Wesmael, 1835 Braconidae: Opiinae
Opius cingulatus Wesmael, 1835 Braconidae: Opiinae
Phaedrotoma rex (Fischer, 1958) Braconidae: Opiinae
Phaedrotoma variegata (Szépligeti, 1896) Braconidae: Opiinae

External links: Search the internet:
Biodiversity Heritage Library
Bladmineerders van Europa
British leafminers
Encyclopedia of Life
Fauna Europaea
NBN Atlas
NHM UK Checklist		 Find using Google
Find using Google Scholar
Find images using Google

XHTML Validator Last updated 09-Jul-2019 Brian Pitkin Top of page