Monarchs and Milkweed: A Migrating Butterfly, a Poisonous Plant, and Their Remarkable Story of Coevolution
The fascinating and complex evolutionary relationship ofthe monarch butterfly and the milkweed plantMonarch butterflies are one of nature's most recognizablecreatures, known for their bright colors and epic annual migrationfrom the United States and Canada to Mexico. Yet there is much moreto the monarch than its distinctive presence and mythic journeying.In Monarchs and Milkweed, Anurag Agrawal presents a vividinvestigation into how the monarch butterfly has evolved closelyalongside the milkweed—a toxic plant named for the sticky whitesubstance emitted when its leaves are damaged—and how thisinextricable and intimate relationship has been like an arms raceover the millennia, a battle of exploitation and defense betweentwo fascinating species.The monarch life cycle begins each spring when it deposits eggson milkweed leaves. But this dependency of monarchs on milkweeds asfood is not reciprocated, and milkweeds do all they can to poisonor thwart the young monarchs. Agrawal delves into major scientificdiscoveries, including his own pioneering research, and traces howplant poisons have not only shaped monarch-milkweed interactionsbut have also been culturally important for centuries. Agrawalpresents current ideas regarding the recent decline in monarchpopulations, including habitat destruction, increased winterstorms, and lack of milkweed—the last one a theory that the authorrejects. He evaluates the current sustainability of monarchs andreveals a novel explanation for their plummeting numbers.Lavishly illustrated with more than eighty color photos andimages, Monarchs and Milkweed takes readers on anunforgettable exploration of one of nature's most important andsophisticated evolutionary relationships.