Hendersonia acicola on pine needles infected by Lophodermella sulcigena

Hendersonia acicola normally infects only needles already infected, in July‐August of their first year, by Lophodermella sulcigena . Secondary infection, by H. acicola , occurs at the base of the L. sulcigena lesion either in August‐October of the first year (early secondary infection) or after fruiting of L. sulcigena in June‐July of the second year (late secondary infection). Early secondary infection prevents fruiting of L. sulcigena . An intercellular matrix forms at the base of the L. sulcigena lesion in response to both early and late secondary infection and rapid tissue disorganisation and disintegration ensues. Secondary infection decreases with increase in height up the tree and often results in needle breakage.