Heterarthrus vagans (Fallén, 1808)
Alnus glutinosa, Staelduinse bosch: mine, and cocoon with prepupa
Alnus glutinosa, Nieuwendam: living larva in the mine
Alnus x spaethii, Belgium, prov. Liège, Hermalle-sous-Argenteau; © Jean-Yves Baugnée
A large, practically full depth brownish blotch, without a preceding corridor. The mine begins somewhere on the leaf, and expands in all directions, without having much consideration with even major veins. In this respect the mine differs from that of Fenusa dohrnii on the same host plant. Moreover, as a rule there is just one mine per leaf. The full grown larva makes a disc-shaped cocoon within its mine, with a diameter of about 7-9 mm.
Contrary to F. dohrnii the larva is rather vividly pigmented (picture above). Thus can easily be observed without dissecting the mine. Like in almost all sawflies the larva lies belly-up in its mine.
Alnus cordata, glutinosa, incana, orientalis, x spaethii, viridis.
Larvae from June to October (Buhr, 1941a); hibernation as prepupa in the cocoon (Seidel, 1926b; van Frankenhuyzen & Freriks, 1970c).
BE recorded (Fauna Europaea, 2008).
NE recorded (van Ooststroom, 1976).
LUX recorded (Chevin, Ellis & Schneider, 2011a).
distribution within Europe
From Sweden and Finland to the Iberian Peninsula, Italy and Bulgaria, and from Ireland tot he Ukraine (Fauna Europaea, 2008).
Heterotoma, Phyllotoma vagans; ? Heterarthrus fruticicolum Ermolenko, 1960.
The egg is deposited in a cavity that is made with the ovipositor just below the upper epidermis. In the subsequent days the cavity is filled with frass and turns brown (Pieronek, 1966a; van Frankenhuyzen & Freriks, 1970c).
Mines in the older leaves. The leaf tissue of young leaves dies off so soon after being damaged that the larvae would not be able to survive.
Contrary to F dohrnii about 30% of the adults are males; vagans is not parthenogenetic.
Ahr (1966a), Altenhofer (2003a), Altenhofer, Hellrigl & Mörl (2001a), Beiger (1979a, 1980a), Beneš & Holuša (2015a), Blank ao (1998a), Buhr (1933a, 1941a, 1964a), Chevin, Ellis & Schneider (2011a), Csóka (2003a), Diškus & Stonis (2012a), Drăghia (1968a, 1972a, 1974a), van Frankenhuyzen & Freriks (1970c), van Frankenhuyzen & Houtman (1972a), van Frankenhuyzen Houtman & Kabos (1982a), Haris (2009a), Hartig (1939a), Hering (1957a), Huber (1969a), Kollár & Hrubík (2009a), Humble (2010a), Liston (1995b), Liston & Jacobs (2012a), Liston, Mutanen & Viitasaari (2019a), Liston & Späth (2005a), Lorenz & Kraus (1957a), Maček (1999a), Matošević, Pernek, Dubravac & Barić (2009a), Michalska (1972a, 1976a), Nowakowski (1954a), van Ooststroom (1976a), Pieronek (1962a, 1966a), Popescu-Gorj & Drăghia (1968a), Pschorn-Walcher & Altenhofer (2000a), Robbins (1991a), Scobiola-Palade (1974a), Seidel (1926b), Skala (1951a), Skala & Zavřel (1945a), Sønderup (1949a), Stammer (2016a), Starý (1930a), Surányi (1942a), Taeger, Blank & Liston (2006a), Taeger ao (1998a), Viramo (1969a), Wahlgren (1944a, 1951a, 1963a), Zoerner (1969a, 1970a).