Ceutorhynchus napi Gyllenhal, 1837
Brassica napus, Hungary, Mosonmagyaróvár © László Érsek: larva boring in the stem
th stem swells and tears open (picture taken on April 9) …
… and becomes seriously destroyed (April 22)
The larva essentially is a borer in petiole or stem. Some larvae (“many”, according to Hering [1957a], “1-3”, according to Scherf [1964a]) live there together in a cavity. At that point the stems is galled and swollen. From there sometimes a larva strays into the leaf blade.
Larvae in April-July (Scherf, 1964a).
BE observed (Curculionidae.be, 2010a).
NE observed (Fauna Europaea, 2007; Heijerman, 1993a).
LUX not observed (Fauna Europaea, 2007).
distribution within Europe
From Denmark and Poland tot the Iberian Peninsula and from France to Bulgaria; not in the British Isles (Fauna Europaea, 2007).
Buhr (1964b, 1965a), Günthart (1949a), Heijerman (1993a), Hering (1957a), Scherf (1964a), Tomasi (2014a), Vorst (2010a).