![]() ![]() ![]() Non-migrating monarchs do seem to show higher infection rates (More details can be found at ). While this protozoan-monarch relationship has probably existed for millennia, multi-generational feeding from the same plants is allowing the parasites to accumulate to abnormal levels. Heavily parasitized butterflies may be weakened, unable to mate or deformed and incapable of long-distance flight many won’t make it out of the chrysalis. Additionally, there is a parasitic protozoan ( Ophryocystis elektroscirrha) infecting the monarch population. Therein lies the problem: migrating monarchs, leaving areas where native milkweed is naturally diminishing with cooler weather, may encounter tropical milkweed and be induced to mate and lay eggs-and not migrate. In warmer regions, it will flower year round. ![]() Its bursts of orange and yellow flowers and ease of cultivation make it appealing to home gardeners. A very common milkweed is tropical, or scarlet, milkweed ( Asclepias curassavica ), a non-native to the U.S. Ironically, this may in some ways be detrimental. One of the many ways people aid monarchs is by planting milkweed. (I still find it incredible that humans have invented insecticides, and then wonder in amazement that those same insecticides are actually killing insects). Of course, this all requires a lot more research, and it may never be completely understood. Other monarch threats are the same old culprits hurting so many other animal and plant populations: habitat loss, drought (especially for the California population), climate change and extremes of temperature, logging in the Mexican overwintering sites, and pesticides of particular concern are the neonicotinoids, a type of insecticide implicated in the decline of bees. “We’ve seen a 20-fold increase in its use over the last 20 years, and during that same time period monarch populations have declined by 90%,” says Jepsen. Much of that milkweed is indeed considered a weed in agriculture, and so is destroyed by herbicides especially harmful are herbicides containing glyphosate, which annihilates native milkweeds and other plants, but not the crops genetically modified to tolerate it. The hatchling caterpillars must feed on milkweed before pupating and eventually emerging as adults. Jepsen indicates “the greatest concern is the decline in milkweed plants, the monarch’s host plant.” Many of the eastern population monarchs spend the spring and summer in the Midwest and central Canada, where they lay eggs on milkweed. The eastern population famously makes the long, multigenerational migration from as far north as Canada to spend winter in central Mexico, while the third group doesn’t migrate at all, staying more or less year round in South Florida, Texas and the Caribbean. Those west of the Rocky Mountains generally spend winter months in locations along the California coast (with some flying to Mexico). However there are three main populations-still the same species-of monarchs in North America. Monarchs are found throughout the world, even on remote Pacific islands. Lincoln Brower-one of the world’s most renowned monarch biologists-to request that the Federal Government list the monarch as a threatened species under the Endangered Species Act. There are currently about 33–35 million that may sound like a lot of butterflies, but it’s low enough that one major storm could be catastrophic.” In August 2014, Xerces joined with other conservation groups and Dr. She related “when it was counted last winter, the monarch population that overwinters in Mexico represented about 10% of the average population size over the past 20 years. I spoke to Sarina Jepsen, Endangered Species Program Director at the Xerces Society for Invertebrate Conservation. Cheering on this limp, nearly helpless little orange and black folded mass of color for the almost ten minutes it took to be free of the chrysalis, this made me really want to explore the monarch’s world. But watching the struggle up close is different, both emotional and enlightening. We’ve all seen the photos, and read about the basic butterfly life stages: Egg, larva, pupa, adult. ![]() I was recently fortunate to get to watch monarch chrysalises develop, and was incredibly lucky to find one breaking open, with a monarch emerging. Given our many host and nectar plants here at Fairchild, we have loads of butterfly activity throughout the Garden. We need to look deeper into what’s going on and what we can do about it so we don’t lose this beautiful, iconic animal.īutterflies and plants are intricately and intimately connected. Precipitous declines in monarch populations have been reported. But soon they could be hanging out with the passenger pigeon and the dodo. Monarch butterflies are plentiful and seem to be everywhere, so we take it for granted that they will always be here. As published in the Miami Herald, 12/4/14. ![]()
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