Interesting article in The Boston Globe about the spread of the hemlock wooly adelgid (Adelges tsugae) throughout New England. The ISW has certainly covered this insect pest before, including this NPR story about the problems caused by the adelgid in Massachusetts. Now there is even more bad news: while biologists once thought that the adelgid could not become a problem in the more northern climes of Vermont and Maine, climate change has busted a hole in that assumption. A nice cold winter freeze will kill the insects, but recent climate data indicates that the average minimum temperature in upper New England has risen several degrees over the past few decades. That means it is getting less and less likely every year that a killing freeze will come by and wipe out any lingering adelgids - bad news for the hemlock trees!