Blasticotoma filiceti Klug, 1834
mine
The mine, actually a larval cell, consists of a short corridor in the rachis, barely 2 cm in length -hardly longer than the larva itself-, usually at about a decimeter above the ground. The mine has an opening at the level of the rear end of the larva, and another one, much smaller, at the level of its head. Sometimes several larvae occur in the same rachis. Around the mine the rachis over a few cm has turned brownish black. The larva does not feed on the plant tissues, but on the sap that oozes into its cell. The larva produces at the rear opening a mass of froth, similar to the froth made by a spittle bug, but tougher, more resistant to drying out. Usually ants are attracted to the froth, because of its sugar content. The mine can be found easiest by looking for a combination of ants, a black discolouration of the rachis, and some withered leaf segments nearby.
host plants
Filicales, oligophagous
Athyrium distentifolium, filix-femina; Dryopteris filix-mas.
Also other ferns are mentioned sometimes (Polystichum; Onoclea struthiopteris; Pteridium aquilinum), but Lady-fern doubtless is the most important host plant.
phenology
Full grown larvae in end July – early August.
BENELUX
BE recorded (Verheyde ao).
NE recorded (de Meijere, 1911a).
LUX not recorded (Fauna Europaea, 2008).
distribution within Europe
From Sweden and Finland tot the Pyrenees, and from Ireland to the Ukraine (Bowdrey, 2008a; Fauna Europaea, 2008).
larva
Greenish white with pale brown head (de Meijere).
notes
Just like the “mines” of Cystiphora species with almost as much right one could consider these structures galls.
references
Birjukova & Novgorodova (2008a), Blank ao (1998a), Bowdrey (2008a), Buhr (1964a), Haris (2012a), Hering (1957a), Hoop (1983a), Knight & Howe (2006a), Liston (2007a), de Meijere (1911a), Mol (2017a, 2021a), Pschorn-Walcher & Altenhofer (2006a), Redfern & Shirley (2011a), Robbins (1991a), Shcherbakov (2006a, 2008a), Taeger, Altenhofer, Blank, ao (1998a), Taeger, Blank & Liston (2006a), Mol (2017a), Taeger ao (1998a), Tomasi (2014a), Verheyde, Alberts & Mol (2018a).