Leaf-mine: 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 larva is described by Nowakowski (1973), Dempewolf (2001: 117) and illustrated in Bladmineerders van Europa.

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

Puparium: 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 pupariua, 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 pupal chamber, but anchored to the inner wall of the mine by means of a thread. Often several puparia 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 puparia 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 inpygmaea. 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 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 Britain:

Hosts elsewhere:

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

Time of year - adults: Unknown.

Distribution in Great Britain and Ireland: Widespread in Britain including London (Hampstead), Middlesex (Scratch Wood), Oxfordshire (Oxford), Suffolk (Chillesford), Dunbarton (Bonhill) (Spencer, 1972: 104), Warwickshire (Coventry, Holbrooks) (Robbins, 1991: 136); Cambridgeshire, East Norfolk, East Suffolk, Pembrokeshire, West Kent, West Norfolk and West Suffolk (NBN Gateway - N.B. includes Watsonian Vice Counties having publicly available records that fall within or overlap the vice county border at 10km resolution or better i.e. a record for a vice county may relate to an adjacent vice county - for included datasets see NBN Grid map below).

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

NBN Grid map: Note that not all datasets on the NBN Gateway may be available on the map below. If you are an NBN Gateway registered user you can request access for missing datasets via the link 'Open interactive map in new window' below.

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 (Martinez in Fauna Europaea).

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

NBN interactive distribution map(s) of known host species in Great Britain and Ireland and elsewhere:

Parasitoids in Britain and elsewhere:

Biodiversity Heritage Library
Bladmineerders van Europa
British leafminers
Encyclopedia of Life
Fauna Europaea [128511]
NBN Gateway