Orchestes fagi (Linnaeus, 1758)
Fagus sylvatica, Belgium, prov. Antwerp, Mol © Carina Van Steenwinkel
mine with fresh cocoon
Fagus sylvatica, Duin en Kruidberg: mine with old cocoon
Oviposition in the underside of the midrib, rarely in a thick lateral vein. At this site the vein swells, and splits open over a few mm. The larve begins by making a short mine in the midrib, but soon enters the blade with an the narrow, but gradually widening corridor that generally runs towards the leaf tip. The final part of the mine is a broad blotch that generally occupies a initially part of the leaf tip or leaf margin. Frass in the corridor part in an indistinct central line, higher up it is irregular, often also in longer threads. Against the end of May a globular cocoon is secreted by the larva inside the mine; here pupation takes place.
The mine initially is whitish, but it turns brown soon. Later the mine withers away totally, but the infestation remains visible in the ravaged leaves, that still show the oviposition scar and often also the first part of the corridor.
Larvae in April-May (Scherf, 1964a).
BE recorded (Curculionidae.be, 2010).
NE recorded (Heijerman, 1993a)
LUX not recorded (Fauna Europaea, 2007).
distribution within Europe
From Norway, Ireland and France eastwards till Poland, the Balkan Peninsula and Italy.
Rhynchaenus, Euthoron, fagi
In the Netherlands rather common. At times a mass-outbreak may occur, during which hardly any leaf remains undamaged (von Frauenfeld, 1864a; Oudemans, 1929a). Very common in the UK (Morris, 1993a).
After the female has come out of the winter diapause she must first eat (beech leaves, sometimes hawthorn, of which the leaves unfold somewhat earlier) to let the eggs in her develop; only then oviposition can take place. Already in a week after bud burst the tissues of the beech leaves begin to toughen, and the larvae then cannot complete their development. Obviously, only one generation per year is possible. A perfect synchronisation of the hibernating female with bud burst is of vital importance (Bale, 1984a).
Bale (1981a, 1984a), Bale & Luff (1978a), Beiger (1979a), Buhr (1933a), Caillol (1954a), Csóka (2003a), van Frankenhuyzen & Houtman (1972a), van Frankenhuyzen, Houtman & Kabos (1982a), von Frauenfeld (1864a), Haase (1942a), Hartig (1939a), Heijerman (1993a), Hering (1924a, 1930a, 1935a, 1957a), Huber (1969a), Kirichenko, Augustin & Kenis (2018a), Kleine (1924a/1925a), Kollár (2007a), Kollár & Hrubík (2009a), Maček (1999a), Matošević, Pernek, Dubravac & Barić (2009a), le Monnier (2003a), Morris (1993a), Nowakowski (1954a), Oudemans (1929a), Rheinheimer & Hassler (2010a), Robbins (1991a), Scherf (1964a), Seidel (1957a), Skala (1951a), Skala & Zavřel (1945a), Sønderup (1949a), Starý (1930a), Tomov & Krusteva (2007a), Trägårdh (1910a), Vorst (2010a), Zoerner (1969a, 1970a).