Last winter, there was finally some good news for the monarch butterfly – the dapper orange and black species with white polka dots on their bodies. In the winter of 2021-2022, the population numbers were up 35% over the previous year. However, they are still down 85% since the 1990s. If you’re like me, you remember seeing monarchs and maybe even catching them when you were a kid. Viceroy butterflies, an orange mimic of the monarch, were seen more often but not as highly prized by us young butterfly aficionados.
Changes to weather patterns, more cars on the roads, herbicides that control milkweed, habitat loss and fragmentation along their migration route, and insecticides have all taken their toll on the charismatic monarch. Even with last year’s increased overwintering numbers, the population is about 40% of the number needed for a stable community. Nearly all monarchs in the world overwinter in an area totaling approximately 7 acres. That tiny area makes for a fragile population.
Monarchs have the most amazing migration I’ve ever encountered. Rather than flying the same route their parents and ancestors have flown for millennia, the four generations of monarchs per year each fly only part of the route. In spring, butterflies that have overwintered in the high, fir forests of Mexico migrate to Texas. They lay their eggs on milkweed there, and only milkweed, then die. Their eggs hatch into caterpillars, then pupate and “eclose” or emerge into the orange and black adults we are most familiar with. This second generation then flies north, following the sprouting milkweed. They then lay eggs on milkweed. Then, the third generation does the same. The fourth generation reaches the northernmost limits of the migration, as far north as southern Canada, then turns south and flies all the way back to Mexico. This fourth generation will overwinter there and fly north to Texas in the spring.
How something as tiny as a butterfly can be hard-wired to fly a migration route it has never seen, and further to know which section of the route it is supposed to fly, is beyond my understanding. Undoubtedly, they respond to hours of daylight, temperature, the availability of host plants, and probably other environmental cues, but it is still astounding.
There has been a movement over the last few years to help the beloved species by hand raising them. Although the inclination to protect the caterpillars from birds, spiders, and other methods of demise comes from a good place, hand-raising can do more harm than good. A highly spreadable protozoa referred to as “OED” can be magnified in captivity, then spread to the wild population.
Rather than risk increasing the disease load of our precious monarch, a better way to help is to plant milkweed. You probably know that monarchs eat milkweed. What you may not know is it is the caterpillar stage that eats it. And they eat only milkweed. No other plant will suffice for raising baby monarchs. The adult butterflies can, and do, sip from many kinds of flowers, but for caterpillars, only milkweed will do.
There are twenty-two native milkweeds in Georgia. The most common ones are increasingly available for purchase.
Butterfly weed – Asclepias tuberosa. This is the 2.5’ tall bright orange flower you may have seen growing on the roadside. This is the only milkweed in our area that does not have milky sap for which “milkweed” is named. It is also the only local one with leaves arranged alternately along the stem. The others have leaves that appear in pairs.
Swamp Milkweed – Asclepias incarnata. This pink-flowered species is true to its name in preference for wet, mucky soils. Grows 2-4’ tall.
Aquatic milkweed – Asclepias perennis. This one is also sometimes called swamp milkweed. Again, this is why we depend on scientific names. This species’ blooms are light pink turning white upon opening. Another great plant for wet areas. Grows 3-6.’
Carolina milkweed – Asclepias cinerea. This purplish-pink species is not commercially available, but you might spot it in the wild.
Common milkweed. Asclepias syriaca This species also has purplish-pink flowers. It can grow 3-5’ tall.
There is also a tropical milkweed available for purchase (A. curassavica). The species is not native to Georgia and should be avoided. Because it doesn’t die back in the winter, it can collect high populations of the OE protozoa which are then ingested by caterpillars, hurting rather than helping the monarch.
When it comes to saving species, habitat is everything. Plant some milkweed, and give the monarch a way station on their long and miraculous journey.
For more information see: The Monarch Butterfly Fund, The Xerces Society, Journey North, and Monarch Watch.
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Donna H. Black writes articles, fiction, poetry, and more. A horticulturist by training and a writer by choice, she enjoys bringing facts of the natural world to readers. Follow her blog about writing at donnablackwrites.com and find her books on Amazon.com.
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