To say that the monarch butterfly (Danaus plexippus) has fallen upon hard times is something of a colossal understatement. This butterfly's heroic annual migration from its eastern North American summer breeding grounds to a specific spot in the oyamel fit forests of mountainous central Mexico has been systematically monitored since 1995, and during the winter of 2013–2014 the population plummeted to an all-time low; the estimated 35 million butterflies represent a reduction of more than 97% relative to the peak size recorded in 1996. In view of the iconic status of the species, memorably dubbed “the Bambi of the insect world” by Iowa State University entomologist Marlin Rice (Weiss 1999), this dire decline was the motivation behind a petition submitted in August 2014 to the U.S. Fish and Wildlife Service and the Secretary of the Interior to list D. plexippus as a threatened species (http://bit.ly/1zS9CjB). The petition is a sad litany of not only the multitudinous natural shocks their flesh is heir to, including an assortment of predators and pathogens, but also a staggering array of unnatural shocks, including “pesticide use from genetically engineered, pesticide-resistant crop systems that kill milkweeds and nectar sources, as well as by development, logging, and climate change.”
Entomological Society of America
Berenbaum, May, "Road Warrior" (2015). Iowa Monarch Conservation Consortium Publications. 1.