Pity the fly on the pitcher plant. Having landed on the tropical plant’s vaselike structure, which looks no more dangerous than a partially unfurled leaf, the insect tumbles down the six-inch chute and lands in a pool of liquid.Not just any liquid, it turns out, but a brew of digestive juices that gradually dissolves the hapless bug.Scientists have wondered for at least a century what chemicals are in the pitcher plant’s juice — and how it turns insects, with their tough exoskeletons, into mushy dietary supplements. Now a team from Japan has done the first thorough analysis of that fluid, answering some old questions and raising a few new ones.The carnivorous plants, which live mostly in the Asian tropics but have also become popular houseplants in the West, rely on occasional insect snacks to stay nourished, since they mostly grow in nutrient-depleted soil. Charles Darwin himself was fascinated by the plants, and wrote a book about them in 1875.“The fact that a plant should secrete, when properly excited, a fluid containing an acid and ferment, closely analogous to the digestive fluid of an animal, was certainly a remarkable discovery,” he wrote.
