Scientists fear renewed threat to white pine trees

Scientists worry that a fungus targeting white pine forests has mutated and could return more than a century after it first hit the United States.

White pine blister rust comes from a combination of white pines and flowering plants—called ribes (RYE'-beez)—like gooseberries and currants. When infected ribes lose their leaves in the fall, spores of the fungus invade white pines and eventually kill the tree.

When the fungus first hit in 1909, a massive eradication effort including a ban on ribes, helped stem the destruction.

But a Cornell University researcher found a previously immune currant infected with a mutated form of the fungus in 2011 in Connecticut. Scientists now worry the risk may return.

The U.S. Forest Service is leading a research effort into the fungus.

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