SciSun: King for a Day   Leave a comment

It’s good, they say, to be King. But despite the raiment – or at least the name – of royalty, it’s not necessarily a good time for the Monarch Butterfly (Danaus plexippus), the widely-recognized orange and black flier perhaps best known for her annual migrations across North America (and mobs of individual butterflies that occasionally cover trees, camouflaging the foliage in a cloak of brilliant crimson). With numbers falling from over one billion in the 1990’s to 35 million in 2014, flutters of the migrating insects, once an anticipated Spring and Autumn event, is in danger of becoming no more than the flitter of a few stragglers following unseen routes of generations past.

Last month (on the final day of the year, at that!), the US Fish and Wildlife Service (USFWS) initiated the first steps in the process that could ultimately list the Monarch as a threatened or endangered species. While the worldwide, overall population of the butterfly species continues to be relatively healthy (although under environmental pressure and not as abundant as they once were), the concern comes from the decline in butterflies traveling to and from North America – numbers dropping 96.5 percent over the past few decades – and what this fall in Autumn and Spring visitors could mean not only in pretty butterflies visiting our gardens, but directly linked to the food you and I eat; crops grown for livestock; and the same gardens planted for their beauty that could actually be leading to the Monarchs’ decline.

As far back as anyone can research, the Monarch has migrated between central North America – primarily the American Midwest – and the forests of Mexico. (There are also eastern populations that follow the Gulf Coast and move into the Mid-Atlantic area; and an unique western group that only flies between California and neighboring western US and Mexican states. Californians have always been a little different). But one thing that makes the Monarch migrations special, is they are the only insect that moves both ways – in the Spring and Fall – one of the longest migrations of any animal. And on the return trip, each individual has never made that journey before yet instinctively recognizes the way. (As we know, once the butterfly lays its eggs it dies, and newly born butterflies are the ones that have to make the return).

Despite these herculean achievements, the Monarch depends upon one food source both as a larvae and adult: The Milkweed (genus Asclepias) which once was common within North America and may have actually been among the most numerous of all ‘weeds’. Just as the name implies milkweed is considered a weed (despite the ‘milk’ part, which is a bit redeeming); and farmers hate weeds. So do livestock, which usually don’t eat the plants, and if they do it sometimes makes the cattle sick. So much are these plants despised massive attempts to remove every weed are undertaken including mowing, burning, cutting, and poisoning to keep the land clear for crops like corn, wheat, hay and grains. And that leaves the adult Monarch very little to eat as it makes it’s journey; and nothing for the larva (‘caterpillar’) Monarch to eat as it grows. For that matter it doesn’t even leave any place for the larvae to live, as Monarchs only lay eggs on the Milkweed. To make it more convenient for the larva to get a meal, you see.

Milkweed will grow most anywhere.  It's truly outstanding in its field.

Milkweed will grow most anywhere. It’s truly outstanding in its field.

 

Of course in gardens throughout America there are millions of Milkweed plants, many purposely positioned to attract the Monarch and give them a good home. But the most common milkweed sold in nurseries and garden centers is not the native milkweed the butterflies need (Asclepias incarnata), that produces subdued white and pastel flowers and dies off each year; but a foreign species (Asclepias curassavica) that grows year-round, exhibiting colorful pink, red and orange blossoms. Unfortunately the protozoan parasite Ophryocytis elektroscirrha (OE) grows on milkweed. Once eaten, it can cause wing deformities, infection and ultimately kills the butterfly (it seems this one-food diet might not have been the wisest choice for the monarch. But it probably sounded good at the time). In normal conditions, any ill monarch would die before passing on the parasite and the milkweed itself, along with its parasitic hangers-on, would die during the winter and fresh, parasite-free plants would grow in the Spring, with no ill effects to newly-hatched larvae. But as foreign milkweed grows all year – harboring the parasite – illness is just passed from one Monarch generation to another; and some Monarch populations, particularly in mild climates like the Gulf and Pacific Coasts, are abandoning migration to remain among the year-round milkweed. They think they’ve got it made, when they are slowly extinguishing their species.

Intense logging in Mexican forests; climate change; intensive use of resilient pesticides; and even severe storms are other challenges this little insect must face (with a body mass less than a penny, over 500 million were killed in severe winter storms of 2002). But by the simple effort of not disturbing native milkweed, particularly if the plants are along ditches, empty fields, and other un-farmed areas; and buying and planting the natural flower in our own gardens, is something every one of us can do to help save the Monarch. We might not be kings – but with just a little planning, we can all help the King of Butterflies continue to reign.

 

http://www.fs.fed.us/wildflowers/pollinators/Monarch_Butterfly/migration/index.shtml

http://www.illinoiswildflowers.info/weeds/plants/cm_milkweed.htm

^^^

Michonne Says: The flutter-byes eat the milk-flowers and the flowers make them sick? That is very sad. Sometimes I eat flowers all day from when I wake up until it’s time to go back underground (except for nap-times of course, I only dream of flowers then), and later I don’t feel so well either. And I wasn’t even eating milk-flowers.

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