By Kathy Feagan
Big Country Master Gardener
Monarch butterflies (Danaus plexippus) are important pollinators that are well known for being the State Insect of Texas and for their long-distance migration and . . . their recent declines.
The monarch butterfly, with its beautiful black and orange markings, is one of the most recognizable butterflies in America. By consuming milkweeds, they produce cardenolides which make their bright colors that warn it’s predators that they are toxic.
They are originally native to North America, while only non-migratory monarch populations are found from islands in the Pacific Ocean to the western edge of Europe. But the majority of monarchs live and migrate in North America. North American migratory monarchs are divided into eastern and western populations by the Rocky Mountains, limiting their contact. The two populations are not totally isolated from each other and still occasionally interbreed. There are also non-migratory monarchs that remain year-round at the southern end of their breeding range including in parts of Florida, California and even the Gulf coast. There are also populations in Hawaii; Portugal and Spain; and Australia, New Zealand, and elsewhere in this region.
The largest population of monarchs are the Eastern Monarchs which are also largest in range. The eastern population makes upwards of 70% of the total North American monarchs. In the fall, they may fly more than 2,000 miles to reach their overwintering sites in Mexico.
The western North American migratory monarch population is generally found west of the Rocky Mountains. These butterflies annually migrate 300 to 1,000 miles to overwinter in hundreds of clusters of trees along the California coast and northern Baja California, Mexico.
The female butterfly lays each of her eggs, attaching them individually, with a glue she secretes on the leaf of a milkweed plant. Females usually lay 300 to 500 eggs over a two- to five-week period.
A few days later, the eggs hatch into larvae, known as caterpillars. The caterpillars then grow and they spend most of their time eating voraciously. They only eat milkweed, which is why the female lays her eggs only on milkweed leaves.
For about two weeks, the caterpillars eat all they can and then they spin a protective case around themselves and enter the pupa stage, which is also called “chrysalis.” After about a week or two, they complete their metamorphosis and emerge as fully formed, black-and-orange, adult monarch butterflies. If they emerge in the spring or early summer, they’ll start reproducing within days. In the east, only monarchs that emerge in late summer or early fall make the annual migration south for the winter. As the days get shorter and the weather cooler, it’s time to abandon their breeding grounds in Canada and the northern U.S. and head south to the mountains of central Mexico. Some migrate up to 3,000 miles.
The eastern monarchs huddle together on oyamel fir trees to wait out the winter. As the days start growing longer again, they begin to move back north, stopping along the route to lay eggs. Then the new generation continues farther north and stops to lay eggs. The process may repeat over 4 to 5 generations before the monarchs have reached their northern home.
Western monarchs head to California for the winter, stopping at one of hundreds of known areas along the coast, to wait out the cold. When spring comes, they disperse across California and other western states.
Monarchs use the sun to stay on course, and they also have a magnetic compass to help them navigate through cloudy days. They are gifted with extremely efficient muscles that aid them in long-distance flights.
Western monarchs have declined by over 99% since the 1980’s while eastern monarchs have declined by about 80%. The main cause of their decline is lack of milkweed. Farmers have mostly eradicated milkweed from their fields along with using more herbicides and pesticides. Even roadsides have little milkweed for the same reasons. At their winter grounds, logging and development have cleared thousands of acres.
Western monarchs have declined by over 99% since the 1980’s while eastern monarchs have declined by about 80%. The main cause of their decline is lack of milkweed. Farmers have mostly eradicated milkweed from their fields along with using more herbicides and pesticides. Even roadsides have little milkweed for the same reasons. At their winter grounds, logging and development have cleared thousands of acres
What can you do to help? Plant and grow milkweed. According to MonarchWatch.Org, for the South Central region including Texas and Oklahoma the main monarch host plants for this region are A. viridis (green antelope horn milkweed), A. asperula (antelope horn milkweed), A. latifolia (broadleaf milkweed) and A. oenotheroides (Zizotes milkweed). A. incarnata (swamp milkweed) which is mostly limited to river bottoms and A. tuberosa (butterfly weed) which can be found along roadsides and in some grasslands are also used by monarchs. Asclepios tuberosa is locally sold and is a great native perennial. Another plant that will draw not only monarchs, but many, many more butterflies to your yard is Gregg’s Mistflower, along with coneflowers, goldenrod and gayfeather, especially Blazing Star. If you do plant Gregg’s Mistflower beware that it spreads like crazy so plant in containers or in a huge area you’d like to fill! Go to the websites of the Native Plant Society or Lady Bird Wildlife Center for great information on milkweeds and plants for pollinators for our region.
Looking for more opportunities to learn about all things gardening? Join us for our monthly library program. The first program starts at 6:00 p.m. on the 1st Tuesday of the month at the South Library Branch in the Mall of Abilene, and the same program is offered again at 10:00 a.m. on the 2nd Friday of the month at the Downtown Library. Watch the BCMGA website and Facebook page for the topics and dates of these monthly programs or click this link for a list of topics. There are also Saturday Seminars on the last Saturday of the month from February through August at 9:00 a.m. in the Taylor County Extension Office Conference Room. Click here for a list of Saturday Seminar dates and topics.
If you have any questions, call the Taylor County Extension Office at 325-672-6048 or email us at mgardeners@yahoo.com. We hope you visit bcmgtx.org for information on all Big Country Master Gardener events, like us on BCMGA Facebook, and check out training presentations on the BCMGA YouTube channel. Be sure to click the subscribe button! We are here to help you.
