Dothistroma septosporum or Mycosphaerella pini is a fungus that causes the disease commonly known as red band needle blight.

Over 60 species have been reported to be prone to infection and Corsican Pine (Pinus nigra ssp.

The first signs of infection that can be seen are yellow and brown spots that develop on the living needles,[7][8] which soon turn red.

[11][12] Spread initially in moist conditions,[13] the pathogen requires physical transport either through mist and rain, or by direct contact with other infected needles.

This reduces yield of timber growth and weakens the tree, serving as a predisposing factor to other diseases.

[18] It has been observed that delays in the first thinning in East Anglia resulted in high mortality rates in the crop.

[18] The environmental and economic factors behind copper based fungicide treatment of large scale commercial crops makes control difficult and inadvisable.