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


Phytomyza continua Hendel, 1920
[Diptera: Agromyzidae]

Phytomyza continua Hendel, 1920. Arch. Naturgesch. 84A(7) (1918): 158
Phytomyza cardui Hering, 1943. EOS 19: 55. [Synonymised by Spencer, 1976: 405]
Phytomyza polyarthrocera Frey, 1946. Notul. ent. 26: 54. [Synonymised by Spencer, 1976: 405]
Phytomyza zetterstedti Rydén, 1951b. Ent. Tijdschr. 72(1-2): 179. [Preoccupied]
Phytomyza zetterstedtiana Rydén, 1953. Ent. Meddr. 26: 16. [Synonymised by Spencer, 1976: 405]
Phytomyza continua Hendel, 1920; Spencer, 1972b. Handbk ident. Br. Ins. 10(5g): 82, 83 (fig. 268)
Phytomyza continua Hendel, 1920; Spencer, 1976. Fauna ent. Scand. 5(1): 405-6, figs 708-710.
Phytomyza continua Hendel, 1920; Spencer, 1990. Host specialization in the World Agromyzidae (Diptera) : 251, 255, 256 (fig. 959-60).

Leaf-miner: Larva feeds along the mid-rib, predominantly on the lower surface and there is little evidence of gall-like swelling. Pupation takes place at the base of the midrib (Spencer, 1976: 496).

In Burdock the species bores in the petioles, and in Chicory it is a root borer, but in thistles it mainly lives in the base of the midrib, making from there brief excursions into the blade. The midrib somwhat swells, gall-like and obtains a somewhat darker shade. Pupation takes place within 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 Dempewolf (2001: 183).

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).

Whitish; posterior spiracles on an angular projection, each with some 18 bulbs (Spencer, 1976: 496).

Hosts in Great Britain and Ireland:

Carduus       Robbins, 1991: 121
Carduus       Spencer, 1990:
Centaurea       Pitkin & Plant

Hosts elsewhere:

Arctium       Bladmineerders van Europa
Arctium minus Lesser Burdock British Wild Flowers by John Somerville et al. Dempewolf, 2001: 183
Carduus       Spencer, 1976: 405
Carduus       Spencer, 1990: 251
Carduus crispus Welted Thistle British Wild Flowers by John Somerville et al. Bladmineerders van Europa
Cichorium       Bladmineerders van Europa
Cirsium       Spencer, 1976: 405
Cirsium       Bladmineerders van Europa

Time of year - mines: March (Hering, 1957).

Time of year - adults: May-July, September-November.

Distribution in Great Britain: Britain including Breconshire, Cambridgeshire, East Norfolk, Monmouthshire, North Somerset, Oxfordshire and South-west Yorkshire (NBN Atlas).

Distribution elsewhere: Widespread in continental Europe including Austria, Denmark, Finland, France, Germany, Sweden (Spencer, 1976: 405), Belgium, Czech Republic, Latvia, Lithuania, Poland, Spanish mainland and Switzerland (Fauna Europaea).

NBN Atlas links to known host species:

Arctium minus, Carduus crispus

British and Irish Parasitoids in Britain and elsewhere:

Ichneumonoidea - Links to species no longer available  
Chorebus leptogaster (Haliday, 1839) Braconidae: Alysiinae

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