Monarch butterfly in Dyke Marsh. Photo courtesy of of Glenda Booth
Bright orange and black butterflies are zigging and zagging through Northern Virginia in September and October headed south, the migration of monarch butterflies. Each weighing 598 milligrams or one-fifth the weight of a penny, they are headed to central Mexico’s mountains to join up to 100 million that annually cluster like grayish beards on oyamel fir trees at nine to 11,000 feet through the winter. Some will fly 2,000 miles from Canada to reach their winter sites. A western population winters in California.
People are seeing monarchs in backyards, along highways and in natural areas like Dyke Marsh and Huntley Meadows and Riverbend Parks. In mid-August, Alexandrian Jim Waggener spotted 25 in several hours at Meadowood on Mason Neck.
In the 17th century, English colonists named this insect a “monarch” because the orange and black colors reminded them of British royalty, the prince of Orange. Male monarch butterflies have two black spots on their hind wings; females do not.
Life Cycle
Butterflies have four life stages. Female monarchs lay an egg the size of a period on the underside of a leaf, up to 500 to 700 eggs under optimal conditions. Then the parents die.
After the egg hatches, the larva or caterpillar fattens up on milkweed leaves.
“That’s all they do – eat, eat, eat,” said Larry Brindza, who has tagged monarchs for researchers. Monarch caterpillars feed exclusively on milkweed plants, experts contend. Ingested milkweed sap offers protection because predators like birds are repulsed by the taste and toxicity.
The yellow, black and white striped caterpillar outgrows its outer skin or exoskeleton several times and attaches itself to a support by a silky adhesive substance to become a pupa, a green, bag-like chrysalis. The chrysalis dangles delicately and becomes clearer until it transforms into a fully-formed butterfly and splits open. The new, delicate butterfly pumps fluid into its wing veins, dries in the sun, hardens its wings and takes flight.
Spring Journey
The monarch is the only butterfly that regularly has a two-way migration. When spring temperatures rise in Mexico and nectar sources become available, monarchs mate, head north and females lay eggs.
After laying eggs, females live only around 30 days. The eggs become adults and this new generation flies north, mating along the way. The next generation does the same. During warm years, a few of the migrants from the mid-latitudes of the U.S. are fifth generation monarchs.
The human equivalent of the typical monarch’s astonishing odyssey is 11 times around the world, estimates Dr. David Gibo, a Toronto zoologist.
Threatened
Monarch populations are seriously threatened, according to the conservation organization Monarch Watch, largely by habitat loss from ever-expanding development and farming. Some people intentionally destroy milkweed and use harmful herbicides and pesticides. The butterflies’ wintering sites in Mexico are also at risk from logging.
To offset the decline in milkweeds and nectar sources, some people plant milkweeds and nectar-producing plants in their gardens. Monarch Watch certifies monarch-friendly gardens as Monarch Waystations. There are, for example, waystations at Providence Presbyterian Church and Daniels Run Elementary Fairfax; Runnymede Park, Herndon; Riverbend Park, Great Falls; Thomas Jefferson Elementary School, Falls Church; and Knox Presbyterian Church, Falls Church.
The Dale City, Interstate-95 rest stop managed by the Virginia Department of Transportation is part of a national coalition dedicated to creating habitats on rights-of-way for pollinators, including monarch butterflies.
How to Help
• Plant common milkweed.
• Create a monarch waystation.
• Plant nectar plants.
• Support natural areas.
• Visit https://www.monarchwatch.org/. “No effort is too small to have a positive impact,” says the website.
Monarch Nectar Plants for the Mid-Atlantic Region
SOURCE: National Wildlife Federation
1) Common milkweed, Asclepias syriaca, Pink flowers, up to 8 feet tall, Monarch caterpillar host plant. Drought tolerant.
2) Joe-pye weed, Eutrochium stulosum, Pink/purple flowers, up to 7 feet tall, Great nectar plant that attracts many pollinator species.
3) Swamp milkweed, Asclepias incarnata, Pink flowers, up to 4 feet tall, Monarch caterpillar host plant.
4) Wild bergamot, Monarda stulosa, Purple/pink flowers, up to 3 feet tall, Aromatic foliage. Flowers attract butterflies, bees, and hummingbirds. Summer to Fall
5) Blackeyed Susan, Rudbeckia hirta, Yellow flowers, up to 3 feet tall, Can be biennial or annual. Butterfly attractant. Drought tolerant.
6) Blue mist flower, Conoclinium coelestinum, Blue/purple flowers, up to 3 feet tall, thin regularly to control spread by runners.
7) Butterfly milkweed, Asclepias tuberosa, Orange/yellow 2 L Monarch caterpillar host plant. Drought tolerant.
8) Common boneset, Eupatorium perfoliatum, White flowers, up to 6 feet tall; Tolerates sandy or clay soils but needs constant moisture.
9) Dense blazing star, Liatris spicata, Purple flowers, 4 feet tall, Highly adaptable and easy to grow. Attracts many butterflies, bees, and hummingbirds.
10) Eastern purple coneflower, Echinacea purpurea, Pink/purple flowers, up to 5 feet tall, Can become aggressive. Attracts a number of butterflies, native bees, and hummingbirds.
11) Flat-top goldentop, Euthamia graminifolia, Yellow flowers, up to 6 feet tall, Attracts many species of bees, wasps,flies, butterflies, moths, and beetles.
12) Grass-leaved blazing star, Liatris pilosa, Purple flowers, up to 4 feet tall.
13) Narrow-leaved mountain-mint, Pycnanthemum tenuifolium, White flowers, up to 3 feet tall, Attracts bees, butteries, and birds.
14) Narrow-leaved sunflower, Helianthus angustifolius, Yellow flowers, 3 to 6 feet tall, Important nectar source for fall migrating monarchs. Latest flowering sunflower species.
15) New England aster, Symphyotrichum novae-angliae, Pink/purple flowers, 6 L/M One of the latest fall-blooming plants. Frequented by bees and pre-hibernation bumble bee queens.
16) New York ironweed, Vernonia noveboracensis, Purple flowers, up to 8 feet tall, Easy to grow and tolerates a wide range of soils, although prefers rich, moist soils.
18) Smooth blue aster, Symphyotrichum laeve var. laeve, Blue/purple purple flowers, up to 4 feet tall, Larval host of the pearl crescent butterfly.
19) Spotted bee balm, Monarda punctata, White/pink/yellow flowers, up to 3 feet tall, Drought tolerant. Annual plant.
20) Wingstem, Verbesina alternifolia, Yellow flowers, up to 6 feet tall, Attracts numerous insects, especially bumble bees.
21) Wreath goldenrod, Solidago caesia, Yellow flowers, up to 3 feet tall, Drought tolerant.