Tachyerges stigma (Germar, 1821)
Oviposition in the base of the midrib, without giving rise to a oviposition scar. The larva initially bores inside the midrib. Later it leaves the midrib, forming a broad corridor in the blade, that widens into a blotch. Finally the legless larva pupates in a globular cocoon inside the mine. Because the mine develops at a time that the leaf is fully developed, mined leaves are not disfigured.
Betulaceae, Salicaceae; narrowly polyphagous
Roques (1998a) moreover mentions Populus alba, nigra, but this is not supported by Hering (1957a), Scherf (1964a), Robbins (1991a) or Morris (1993a).
Larvae in May and August (Hering, 1957a), June-August (Scherf, 1964a); adults emerge in August (Reinheimer & Hassler, 2010a).
BE observed (Delbol, 2009; Curculionidae.be, 2010).
NE observed (Heijerman, 1993a).
LUX not observed (Fauna Europaea, 2007).
distribution within Europe
From the UK, Germany, Poland and Russia to France, Italy and Bulgaria (Fauna Europaea, 2007).
Only shortly ago it was discovered that T. stigma comprised a second species viz., T. pseudostigma (Tempère, 1982). Information before that time should be used with caution.
Bachmaier (1965a), Caillol (1954a), Heijerman (1993a), Hering (1930a, 1957a), le Monnier (2003a), Morris (1993a), Reinheimer & Hassler (2010a), Robbins (1991a), Roques (1998a), Scherf (1964a), Viramo (1962a), Vorst (2010a).