Crumenulopsis-canker of Pine - Crumenulopsis sororia
Symptoms / species
Impact / measures
Elongated cankers on twigs and thin branches of several pine species, resin flow and dark discoloration of the cankered tissues. Occasionally also associated with slight shoot dieback. More rarely cankers on stems, mostly at their basis. In the cankers, blackish spore cushions are produced, from which asexual spores known as Digitosporium piniphilum are dispersed. These spores are branched and pale brown. Sexual fruiting structures are apothecia, disc-shaped, grey-black and about 1mm in size (hand lens). The cankers can be mistaken for hail wounds and other wounds, the dieback with Scleroderris-disease or Diplodia-dieback; stem cankers and resin flow may also be mistaken for the quarantine organism Gibberella circinata, cause of pitch-canker of pines.
Affected tree species
In Austria the symptoms have so far been restricted to twigs and branches up to a diametre of 2cm as well as to shoots. Many exotic and European pine species can be infected. Infection occurs by the sexual spores, which are spread by wind and rainsplash. The germinating tubes of the spores enter the bark via small wounds causing there the canker growth.
Curative measures Commonly none necessary; if cankers are more common in certain stands, cases shouls be reportes (check for pitch-canker!)
Crumenulopsis sororia: small canker on a twig
Crumenulopsis sororia: conidia of the asexual stage Digitosporium piniphilum