Each fall Monarch Watch distributes more than a quarter of a million tags to thousands of volunteers across North America who tag Monarchs as they migrate through their respective areas. These “citizen scientists” capture monarchs throughout the migration season, record the tag code, tag date, gender of the butterfly, and geographic location, then tag and release them. At the end of the tagging season, these data are submitted to Monarch Watch and added to their database to be used in research.
Tags are tiny, lightweight, round stickers. They are a little larger than a hole-punch, about 9 mm in diameter. Each tag has a unique ID number. When a tag is recovered (found again), valuable information about migration is revealed.
The tag is placed on the underside of the hindwing of the Monarch. This tagging method places the tag close to the center of lift and gravity for the butterfly so as to not interfere with flight or otherwise harm the butterfly.
According to Monarch Joint Adventure, “The purpose of tagging Monarchs is to associate the location of original capture with the point of recovery for each butterfly. The data from these recaptures are used to determine the pathways taken by migrating Monarchs, the influence of weather on the migration, the survival rate of the Monarchs.
Coded tags are attached to Monarchs when they are captured before or during their southbound migration, and recovered when Monarchs are found throughout the migration or overwintering season. Citizen scientists record the date, location, Monarch gender, and unique tag number for each fall-migrating monarch that they tag and then submit these data to be used in research. The tags and tagging process do not harm the butterflies, and the data collected have the potential to answer many important questions about monarch biology and conservation.”
Tagging helps answer questions about the origins of Monarchs that reach Mexico, the timing and pace of the migration, mortality during the migration, and changes in geographic distribution. For example, by tagging Monarchs and collecting data, we have learned that these butterflies can travel at least 170 miles in a single day and that they have traveled as far as 3,000 miles. In fact, tagging led to the discovery of the monarch’s winter home in Mexico. (Read more of this fascinating story here.)
Monarchs can travel between 50-100 miles a day; it can take up to two months to complete their journey. The farthest ranging Monarch butterfly recorded traveled 265 miles in one day.
Monarch Watch, the Southwest Monarch Study, and Monarch Alert all have monarch tagging programs and are always looking for more citizen scientists; find the program that’s best for you and get involved!
It is that time of year when Monarch butterflies are starting their long migration south to Mexico. During the next three months, millions of Monarchs will travel 2500-3000 miles across Canada and the United States headed for warmer weather in Mexico.
During their migration Monarch butterflies need to stop and refuel on flowers.
The Monarchs (Danaus plexippus) fly during the day, typically traveling alone. They do not migrate in flocks like many birds. But in the early evening, they will rest in trees. Sometimes they cluster in small groups, and sometimes they form large clusters. These clusters of Monarchs are called roosts. Most roosts last for only a night or two but sometimes these gatherings may last as long as two weeks.
Why do monarchs roost? According to Journey North, “One hypothesis is that roosting behavior is an anti-predator strategy. Cool temperatures paralyze monarchs, making them vulnerable to predators. A roost provides safety in numbers. When overnight temperatures are warm, monarchs may not aggregate as tightly or roost at all. Perhaps monarchs shift to roosting behavior when cold overnight temperatures make them vulnerable.”
A small group of Monarch butterflies gathers together to rest and to protect themselves at night.
Where do Monarchs roost? Roosts are more likely found in certain habitats but are not consistently found in the same place. They vary from year to year. Roosts can often be found near nectar sources, in trees that are downwind, and near a major flyway. Flyways are typically near valley streams or depressions that provide a cool moist environment. (https://journeynorth.org/tm/monarch/FallRoosts.html)
One of the best ways to follow the fall migration is to track where they are forming roosts. Journey North keeps and posts data collected by citizen scientists on where roosts are being observed. The roost map shows where there are large concentrations of monarchs. Week by week, it reveals the fall migration pathways to Mexico and the pace of the migration.
We all know that Monarch larvae eat Milkweed plants, but there are other insects that also use Milkweed as a source of food. We must realize that most of these insects serve a purpose within their respective ecosystems. It is important to remember that species diversity is necessary for a healthy ecosystem. Feel good about providing habitat and resources for another species in your garden.
The reason that many of them are black and orange like Monarchs is that they use the same defense mechanism called “aposematism” where their black and orange coloration warns predators of their toxic/bitter taste caused by cardiac glycosides which they acquire from milkweed plants they feed on.
Here are some of the insects you will find on milkweed:
Red Milkweed Beetle (Tetraopes tetrophthalmus)
Distribution: Their range matches the distribution of Common Milkweed (Asclepias syriaca), basically the Northeast quadrant of North America.
Harmful to Monarch caterpillars/eggs? No. They are herbivores and only eat milkweed. They are harmless to monarch larvae and eggs so you can leave them on your milkweed plant if you have enough to go around. The best method to remove the bugs from your milkweed plant is to grab them and throw them into a bucket of soapy water.
Identification: Red/orange in color with oval spots all over the body and un-ringed antennae.
Life Cycle: Eggs laid on stems near the ground or just below the surface; larvae bore into stems, overwinter in roots, and pupate in spring; adults emerge in early summer.
Small Milkweed Bug (Lygaeus kalmii)
Distribution: Throughout the US and Southern Canada.
Harmful to Monarch caterpillars/eggs? Sometimes. They are mostly herbaceous and will suck nectar from flowers and sometimes feed on milkweed seeds. However, they have been reported to be predators, especially in spring when milkweed seeds are scarce, feeding on Honey Bees, Monarch caterpillars and pupae, and Dogbane Beetles, among others.
Identification: They adult is black with a broad orange/red band on the forewing, forming an “X” shape. Their head is black with a dull red spot on top. In eastern specimens, forewings are all black, but western specimens have large white spots. (Bugguide.net)
Life cycle: Eggs are laid on Milkweed in spring, one or more generations per year. Adults overwinter.
Large Milkweed Bug (Oncopeltus fasciatus)
Distribution: Throughout North America and from Central America through Mexico and the Caribbean to southern areas in Canada.
Harmful to Monarch caterpillars/eggs? No, they do not feed on Monarch larvae or eggs so they are harmless and play a role in the ecosystem. However, they do feed on the seeds, leaves, and stems of Milkweeds (Asclepias spp). Damage to the plants can deplete resources for Monarch caterpillars. You can control their population by removing the seeds pods from the milkweed plant.
Identification: Adults are overall black and orange with a black band in the middle and two large black spots in front and back. Nymphs are bright orange and develop black spots late.
Life Cycle: Eggs are laid in Milkweed seed pods or in crevices between pods. About 30 eggs are laid a day, and about 2,000 over a female’s lifespan, which lasts about a month during the summer. One or more generations per year. They can’t survive cold winters, so they migrate south in the fall. They overwinter in the southern Atlantic and Gulf coast states where they feed and breed and gradually migrate north again in the spring and summer.
Distribution: Widespread in North America east of the Rocky Mountains, south to northern Mexico.
Harmful to Monarch caterpillars/eggs? Technically, no, because they are herbaceous. However, they do feed on milkweeds, especially Swamp Milkweed (A. incarnata) and Common Milkweed (A. syriaca). To control populations from eating all of your milkweed, you can pick them off and put them in a soapy bucket of water.
Life Cycle: They often overwinter as adults among leaves such as Mullein (Verbascum). Adults mate on or around milkweed. Eggs are cemented to the underside of leaves. Larvae feed on leaves and drop to the ground to pupate.
Distribution: It is found from southern Canada and south through Texas and Florida in North America.
Harmful to Monarch caterpillars/eggs? No, they are herbivores and only eat Milkweed. But they can defoliate an entire stand of Milkweed in a matter of days. You can try removing these fuzzy little guys by hand if you are concerned that there will not be enough milkweed left to sustain your monarch visitors and are determined to reserve your supply. However, handle milkweed tussock moth caterpillars with gloved hands as the caterpillars have urticating hairs that can result in an uncomfortable rash.
Identification: Early instars appear slightly hairy and gray. Later instars sport tufts of black, white, and orange (sometimes yellow) setae (hairs). The head capsule is black. Larvae grow as long as 35 mm.
Life Cycle: There is one generation per year in the north and two or more in the south. Mature caterpillars occur from June onwards.
Milkweed Tussock Moth(Euchaetes egle) caterpillars are gregarious when young and feed in large clusters.
Milkweed (Oleander) Aphids (Aphis nerii)
Distribution: Throughout North America and from Central America through Mexico and the Caribbean to southern areas in Canada.
Harmful to Monarch caterpillars/eggs? No, but if they become abundant they will suck the life from Milkweed. They also leave behind a trail of sticky, sweet honeydew that attracts Ants, Wasps, and other sugar-loving insects.
Identification: Tiny bright yellow insects with plump, pear-shaped bodies with black cornicles and legs.
Life Cycle: The Oleander aphid reproduces entirely by parthenogenesis (without fertilization). The females are also viviparous, meaning that they do not produce eggs but instead give birth to live young called nymphs, the adult female’s clones.
A recently released study suggests that monarchs are more likely to surviveon milkweed shared with non-predatory insects than on a “clean” plant. They believe this is because the plant has more food options for a predator, which lessens the chance that they go after the monarch. In other words, we might be doing more harm when we try to kill or remove insects we find on milkweed.
My suggestion is to grow lots of milkweed so there is plenty to go around. You can never have too much milkweed!
In July 2014, I accepted a position with Peace Corps Response as a volunteer in El Salvador working at a butterfly exhibit as an Educational Butterfly Farm Management Specialist. My job was to train a few people to cultivate butterflies and to maintain a healthy habitat for them inside the exhibit.
The map of El Salvador showing the Departamento de Morazán where I served as a Peace Corps Response volunteer.
El Salvador is still recuperating from a devastating civil war that wracked the country from 1980 to 1992, leaving at least 75,000 people dead and tens of thousands more displaced. The site where I served as a volunteer, Segundo Montes, is a community made up of five towns in the eastern department of Morazán. Segundo Montes was formed in 1990 by repatriated refugees who’d fled the country’s civil war. After nearly a decade in refugee camps in Honduras, residents returned en masse 28 years ago to reclaim their livelihoods and dignity.
There is a concerted effort to develop tourism along the Ruta de Paz (Peace Highway) from Morazán’s capital of San Francisco Gotera to El Salvador’s border with Honduras, along Highway 7. The butterfly zoo is strategically located along this route and is well-positioned to attract the attention of vacationers headed to the cool air and brilliant sunshine of Perquín, eight miles farther north.
Teaching visitors about butterflies inside the “Mariposario” butterfly exhibit.
Within a few days of arriving at the site, I, along with my local counterpart and a couple of youth volunteers were driven up the mountainous Ruta de Paz to a small town called Arambala. We were tossed about inside the jeep as we traveled over a rough road to an area where the tiny village of El Mozote once stood. El Mozote is famous today because a beautiful memorial stands in its place to honor the 1,000 civilians, mostly women, children, and elderly men, who were massacred during the civil war.
The Mazote memorial features Christ, speaking John 14:27 as recorded in the New Testament, surrounded by martyrs such as Gandhi, Bishop Romero, and Martin Luther King, Jr.
We climbed out of the jeep with our butterfly nets and backpacks. A small frail-looking granjero (farmer), wearing a worn straw cowboy hat with a machete hung on his belt, met us and proceeded to escort us down a quebrada–a ravine–where apparently we would be able to find some butterflies to capture and place in the butterfly exhibit. We were particularly looking for Blue Morpho butterflies and Malachite butterflies because they are rather colorful with their blues and greens.
The Jeep brought us to the top of a mountain in search of butterflies.
I kept slipping and sliding as I tried to navigate down the steep and narrow path. The anciano (elderly man) seemed not to have as much difficulty as I negotiating the trail, so I figured if he could manage, I could too. As I laboriously climbed down through the thick vegetation, I realized I was eventually going to have to climb back up. I had been living in Florida for most of my adult life and had not climbed a mountain in years! How was I going to manage? My knees were already aching. The farther we descended down the mountain, the more worried I became. I could not imagine myself being able to hike back to the vehicle. I was so worried that I could not enjoy the beautiful lush scenery.
Thick vegetation surrounded our path down the hill.
Eventually, we came to an area that opened up and leveled out where an abandoned and dilapidated adobe farmhouse stood. The surrounding area was thick with large mango trees, banana trees, and old citrus trees. I was relieved not to have to negotiate the steep trail, but now I kept fumbling as I tried to walk through the overgrown garden.
Trying to catch butterflies with a net in the thick vegetation.
As I staggered through the vegetation I was elated when I saw several butterflies flying overhead. Vladimir Nabokov, the author of Lolita, once said, “The highest enjoyment of timelessness is when I stand among rare butterflies and their food plants. This is ecstasy, and behind the ecstasy is something else, which is hard to explain. It is like a momentary vacuum into which rushes all that I love.” I, like Nabokov, was caught up in that timeless ecstasy as I surveyed my surroundings and looked upon all the beautiful butterflies. I completely forgot about the anticipated climb back to the vehicle.
Many butterflies tend to fly very fast and erratically as a defense against predators such as birds, so they can be quite challenging to catch with a net. It’s easier to catch a butterfly when it stops to nectar on a flower. Some butterflies, such as the Blue Morphos and Malachites, do not stop to nectar on flowers. Instead, they feed on fruit.
The Malachite (Siproeta stelenes) is named for the mineral malachite, which is similar in color to the bright green on the butterfly’s wings. Typically, the wingspread is between 8.5 and 10 cm (3.3 and 3.9 in). The Malachite is found throughout Central and northern South America, where it is one of the most common butterfly species.
I carefully plodded through the thick undergrowth towards some flowers by a tree, hoping to catch some butterflies. I did not see that there were Malachite butterflies feeding on the fallen mangoes beneath my feet until they all fluttered to escape my intrusion. I was encircled in a cloud of emerald-green jewels. It was magical! I began to giggle with sheer delight. Distracted, I failed to catch a single one of those butterflies with my net.
I began to wonder if these butterflies represented those precious children who were massacred years ago. Many indigenous Central American peoples believe that butterflies are the souls of their dead ancestors. For example, in Mexico, the natives in Michoacán State believe that the Monarch butterflies that return to their homeland mountains every year around the Day of the Dead celebrations in early November are their ancestors returning to visit them. Did the souls of these Salvadorian children return to their homeland as butterflies?
This statue represents the children who lost their lives.
My compadres and I did manage to catch many butterflies that day. We protected them in envelopes nested in small boxes inside our backpacks. Once we had enough butterflies, we began our trek back up the mountain, which, as I anticipated, was even more challenging than the hike down. Again the weathered old man led the way. I was huffing and puffing and working up quite a sweat, trying to keep up.
After a while, he turned around to encourage me and said, “Slow and easy, one step at a time. You will make it. We do not need to hurry.” He then began to tell me his story. He was living with his wife and thirteen children in that abandoned farmhouse when the civil war started. After the massacre at El Mozote, he realized he needed to escape, along with others, to a refugee camp in Honduras to protect his family. With just a few clothes and possessions, leaving their home and farm behind, they began the long arduous journey through the mountains to Honduras. I could imagine him leading the way and stopping every now and then and turning around to his children and saying, “Slow and easy, one step at a time. You will make it. We do not need to hurry.”
I did survive the trek up the ravine thanks to the old man’s reassuring words of encouragement and his persistent example. We stopped by the memorial at El Mozote. The memorial stands on top of a hill surrounded by lush green fields and beautiful mountains. Statues of Martin Luther King, Jr.; Mother Teresa, Pope John Paul II, and Mohandas Gandhi were all represented. I felt privileged not only to be surrounded by great leaders who taught me how to overcome adversity but proud to be standing next to an old Salvadorian farmer who taught me that day how to climb a mountain.
Just as a caterpillar transforms itself into a butterfly, that day I was transformed into a different person by eliminating my self-doubts and overcoming my own personal adversity.
Planting milkweed is one of the easiest ways that each of us can make a difference for Monarch butterflies. There are over 100 species of this wildflower native to North America. Here are just a dozen.
Butterfly Weed (Asclepias tuberosa) is also called Pleurisy Root, Canada Root, Orange Milkweed, and Indian Paintbrush. It takes about two years before it flowers, but it is well worth the wait for the spectacular orange blooms. Unlike other milkweed species, the leaves don’t contain a milky sap.
Native to most of the Continental US and Eastern Canada. (USA: AL , AR , AZ , CA , CO , CT , DC , DE , FL , GA , IA , IL , IN , KS , KY , LA , MA , MD , ME , MI , MN , MO , MS , NC , NE , NH , NJ , NM , NY , OH , OK , PA , RI , SC , SD , TN , TX , UT , VA , VT , WI , WV Canada: NB , NL , NS , ON , QC)
Plant in full sun.
Dry, sandy, well-drained, and slightly acidic soil.
Height 30-40 inches.
Drought Tolerant.
Orange crown-shaped cluster blooms Summer to Fall
Swamp Milkweed (Asclepias incarnata)usually grows in moist areas but it does not require a moist location in the garden. It will grow well in containers and can easily be grown from cuttings. There are different varieties of this milkweed including ‘Cinderella’ Swamp Milkweed (pink blooms) ‘Ice Ballet’ Swamp Milkweed (white blooms.)
Native to most of the eastern US and eastern Canada. (USA: AL , AR , CO , CT , DC , DE , FL , GA , IA , ID , IL , IN , KS , KY , LA , MA , MD , ME , MI , MN , MO , MT , NC , ND , NE , NH , NJ , NM , NV , NY , OH , OK , PA , RI , SC , SD , TN , TX , UT , VA , VT , WI , WV , WY Canada: MB , NB , NS , ON , PE , QC)
Will tolerate shade but also full sun
Height 4 to 6 feet
Needs moist to wet soil
Blooms throughout the summer.
Fragrant flowers
Tolerant of drought conditions once established
Common Milkweed (Asclepias syriaca) is a critical plant for Monarchs but has a spreading root system so it needs plenty of space. It’s a wonderful choice for natural areas and an excellent replacement for tough invasive plants in sunny spots.
Native to most of the eastern US and eastern Canada (USA: AL , AR , CT , DC , DE , GA , IA , IL , IN , KS , KY , LA , MA , MD , ME , MI , MN , MO , MS , MT , NC , ND , NE , NH , NJ , NY , OH , OK , OR , PA , RI , SC , SD , TN , TX , VA , VT , WI , WV Canada: MB , NB , NL , NS , ON , QC , SK)
Full sun, but will tolerate some shade.
Height 2-4 feet
Well-drained soil, even tough clay or dry sand
Rose-colored blooms early to late Summer
Drought tolerant.
Showy Milkweed (Asclepias speciosa) has flowers that resemble a cluster of brilliant pink stars. Although it spreads through underground rhizomes, it is far less aggressive than common milkweed and is an excellent alternative.
Native to the western half of US and Canada (USA: AZ , CA , CO , IA , ID , IL , KS , MI , MN , MT , ND , NE , NM , NV , OK , OR , SD , TX , UT , WA , WI , WY Canada: AB , SK)
Full sun
Height 2 to 4 feet
Grows best in well-drained soil
Drought tolerant.
Blooms late spring to early fall
Antelope Horn Milkweed (Asclepias asperula) s a low, sprawling Southwestern native that thrives in warm, arid zones. It appears early in the spring to provide food for early-migration Monarchs. Because of its long taproot, this milkweed is drought-tolerant and non-aggressive.
Native native to the Southwestern United States. (USA: AZ , CA , CO , ID , KS , NE , NM , NV , OK , TX , UT)
Full sun
Height 1 to 2 feet
Needs dry, well-drained soil.
Blooms early spring to late summer.
Aquatic Milkweed (Asclepias perennis) prefers wet, rich soil and can be found in wetlands and swamps throughout the Southeastern United States. Not to be confused with swamp milkweed (Asclepias incarnata), the flowers are white and restricted to floodplain forest and along streams.
• Perennial in USDA Zones 6-9.
• Native to the Southeastern United States. (AL , AR , FL , GA , IL , IN , KY , LA , MO , MS , SC , TN , TX)
• Partial shade to full sun.
• Prefers moist rich soil.
• Height 1-2 feet.
• Requires regular watering.
Poke Milkweed (Asclepias exaltata) is one of the few milkweeds that are shade tolerant. This low-maintenance, quick-growing native grows wild in most of the Eastern US and Canada, primarily in damp, shady edges of clearings, or on shorelines of ponds and other waterways. Poke Milkweed is often planted as a fast-growing annual in colder zones, where it will tolerate full sun.
• Perennial in USDA Zones 3-7.
• Native to the eastern United States and Canada. (USA: CT, DE, GA, IA, IL, IN, KY, MA, MD, ME, MI, MN, NC, NH, NJ, NY, OH, PA, RI, SC, TN, VA, VT, WI, WV Canada: ON , QC)
• Partial shade.
• Prefers sand, loam, and well-drained soil.
• Height 2-6 feet.
Spider Milkweed (Asclepias viridis), also known as Green Milkweed, and Green Antelopehorn Milkweed, is one of the earliest spring blooming milkweeds with large yellow and green flowers and purple centers.
• Perennial USDA Zones 3-11.
• Native to south central and southeastern United States. (USA: AL , AR , FL , GA , IL , IN , KS , KY , LA , MO , MS , NE , OH , OK , SC , TN , TX , WV)
• Full sun.
• Sandy or rocky well-drained soil.
• Height 1-2 feet.
• Drought tolerant.
Prairie Milkweed (Asclepias sullivantii) is extremely easy to grow and grows in any sunny spot in the garden. It is similar to Common Milkweed but is less aggressive, has slightly smaller flowers, and an overall smooth appearance on the stem, leaves, and seed pods.
• Perennial in USDA Zones 3-7.
• Native to central and south-central United States. (USA: AR , IA , IL , IN , KS , MI , MN , MO , ND , NE , OH , OK , SD , WI Canada: ON)
• Full sun.
• Height 3 feet
• Grows best in consistently moist soil.
Whorled Milkweed (Asclepias verticillata) has very skinny, “whorled” leaves. There are clusters of approximately 20 flowers near the top of each plant. Whorled Milkweed can bloom anytime between July and September, which is later in the year than many other milkweeds. The white flowers can be a greenish-white on some plants. Please note, this species is rhizomatous and will spread.
• USDA Zones 3-9.
• Native to eastern North America and parts of western Canada and the United States.
• Partial shade to full sun.
• Medium, to medium-dry well-drained soil.
• Height 2-3 feet.• Drought tolerant
Narrowleaf Milkweed (Asclepias fascicularis), also known as Mexican Whorled Milkweed, blooms in clusters of lavender, pale pink, purple, white, to greenish shades of flowers. It is one of the easiest milkweeds to grow and establish.
• USDA Zones 3-11.
• Native to California, Nevada, Oregon, and Washington.
• Thrives in full sun.
• Dry to rocky well-drained soil.
• Height 24”- 48” tall.
• Drought tolerant.
Zizotes Milkweed (Asclepias oenotheroides) is sometimes called side cluster milkweed because the flowers form on the sides of the stem, sometimes under the leaves. The flower of this species is unique among milkweeds. Most other milkweeds form a cluster of flowers at the top of the stem. The long, slender hoods extend beyond the stigmatic groove and flare or bow outward at the top. This species survives periodic droughts and occasional mowing.
Distribution: Their range matches the distribution of Common Milkweed (Asclepias syriaca), basically the Northeast quadrant of North America.
Distribution: Throughout the US and Southern Canada.
Distribution: Throughout North America and from Central America through Mexico and the Caribbean to southern areas in Canada.
Distribution: Widespread in North America east of the Rocky Mountains, south to northern Mexico.
Distribution: It is found from southern Canada and south through Texas and Florida in North America.
Distribution: Throughout North America and from Central America through Mexico and the Caribbean to southern areas in Canada.
