Lyme Disease

We’ve known about Lyme for many decades now. So why is it growing? Two factors in particular seem to be making it easier for the tick that carries Lyme, the American blacklegged tick (Ixodes scapularis)—and in Europe, its cousin, the castor bean tick (I. ricinus)—to spread the disease. One is an explosion in the populations of the creatures on whose blood it likes to feed. The other is global warming. Both, of course, are humanity’s…