Douglas Fir needle with galls (31225230214)

Descrição:

Description: Douglas Fir (Pseudotsuga menziesii) needles attacked by two bioagressors : 1) the somewhat inflated bases of the needles colored with violet are galls caused by the Douglas fir needles gall midge (Contarinia pseudotsugae s.l.) 2) the brownish/reddish, dessicated needle tips are probably caused by a fungal pathogen (maybe the Swiss Needle Cast, Phaeocryptopus gaeumannii). These last symptoms could also be caused by physiological problems or by the destruction of the needle conductory tissues by the Contarinia larvae. Date: 6 September 2016, 21:53. Source: Douglas Fir needle with galls. Author: Gilles San Martin from Namur, Belgium.