Stigmina spore-producing structures appear hairy or feathery when seen especially with magnification. Stigmina is found on needles (usually 2nd and 3rd year old needles) of trees showing symptoms very similar to those caused by Rhizosphaera needle cast which causes purpling and loss of older needles, working from the bottom of the tree to top. When spore structures develop for either fungus, the structures are in rows on the affected needles. Current year needles were not affected.
Look closely at the shapes of the Rhizosphaera and Stigmina fruiting bodies because they may look similar if you look too quickly. Stigmina makes the needles look dirtier than Rhizosphaera infected needles. Also, the Stigmina fruiting bodies look like "little spiders" while the Rhizosphaera fruiting bodies look like "smooth bowling balls" especially when seen especially under magnification.