Aecia are pale yellow to bright orange blisters. Aecia produce spores which are wind blown to the alternate hosts. Aeciospores infect the underside of currant or gooseberry leaves where the third type of reproductive structures, uredia, develop. Spores produced by uredia can infect more Ribes leaves throughout the season, thus increasing the number of infections. During late summer and early fall, brown hair-like reproductive structures called telia develop near the uredia.
Teliospores germinate and form another reproductive structure called basidia.
Basidiospores are wind blown to white pine from July to October, causing new infections. There are no fungicides available for prevention or treatment of white pine blister rust. Cultural control methods should include proper pruning and inspection of pine trees. The majority of infections occur on pines within a few feet of the ground. Less air movement and higher relative humidity in the lower story facilitate spore germination and infection.