Monarch the pupa stage. The outside is
Monarch butterflies are not able to survive the cold winters of most of the United States so they migrate southwest each autumn to escape the cold weather (thebutterflysite.com). The monarch is the only butterfly known to make a two-way migration like birds do. Monarchs travel 2,000 to 3,000 miles on their trips.
The monarchs that make the journey each year are part of a “super generation” of butterflies, meaning they are at least four generations removed from the butterflies who made the trip the year prior. In 2002, a winter storm in Mexico killed more than 200 million monarchs; or more than 75 percent of the population (whyy.org). Here we uncover all about monarchs, the history, migration, habitats and disease.The main butterfly that migrates are the Monarch butterflies they are reddish-orange with a black vein like markings. There is a black border around its wings with white spots on it.
They are often mistaken for the Viceroy butterfly. Scientists believe that Viceroys have evolved to look the way they do to take advantage of a monarch’s defense. Since monarchs eat milkweed, they are bad-tasting to birds.The monarch butterfly, like other insects, has several life forms and stages prior to reaching adulthood. The monarch has four distinct life stages: egg, larva (caterpillar), pupa (chrysalis), and adult. Female monarchs can lay over 1,000 eggs in their lifetime.
However, in the wild they can lay an average of 400 to 500 eggs. Monarchs butterflies typically live from two to six weeks except for the last generation of the year, which can live up to eight to nine months. The pupa of a butterfly is called a chrysalis rather than a cocoon. The difference in the structures is that many moths spin a layer of silk for protection and this structure is called a cocoon. They remain in the chrysalis for about eight to twelve days, depending on temperature. The chrysalis is simply the word of the butterfly during the pupa stage. The outside is the exoskeleton, or skin of the pupa. When it becomes time for the larva to become a chrysalis, the caterpillar spins a silk button from which it hangs.
The front of the chrysalis splits open and the butterfly emerges so that’s how they get out. For the wings to unfold the wings have veins that fluid is pumped through which inflate the wings to their proper shape and size. The butterfly waits until its wings are dry to fly. If the butterfly cannot hang upside down while its wings are inflating and hardening, the wings will not form properly and the butterfly will not be able to fly. People often struggle on picking out the males from the females, this is how you can tell.
Males have a dot on the vein on the hindwing and female’s wings are a little wider than males. The male and female also have very different abdomen shapes (butterfly migration and overwintering). Migration is when the monarchs fly to different areas because they can’t stand the cold. Several butterflies migrate like the lepidoptera and the red admiral.
There are two migration times. The first one is spring migration. North American monarchs spend the winter roosting in trees at sites in Mexico and Southern California. They cluster together, covering whole tree trunks and branches.
As the winter ends and the days grow longer, the monarchs become more active and begin a three to five week period of intense mating activity. In Mexico, they begin to leave their roosts during the middle of march, flying north to east looking for milkweed plants on which to lay their eggs. Because decreasing daylength is very important in signaling monarchs to enter diapause, one might suspect that increasing daylength is very important in signaling them to complete diapause. What is diapause? It’s a period of suspended development in an insect, other invertebrate, or mammal embryo, especially during unfavorable environment conditions; However, the scientist Liz Goehring found no evidence to support this hypothesis.
In her series of experiments, increasing daylength had no effect on monarch post- diapause ovarian development, although it may be important in triggering other related changes to diapause completion (canada’s butterfly migration is largest on record). The second one is fall migration it’s when the late summer and early fall monarchs emerge from their pupae, they are physically and behaviorally different from those emerging in the summer. The shorter days, cooler air, and milkweed aging of late summer trigger changes. In the northern part of their range, this occurs around the end of August, when monarchs begin to emerge in reproductive diapause.
Decreasing daylength is one of the most important factors that cause monarchs to emerge in reproductive diapause. In a series of experiments, Liz Goehring found that monarchs reared under constant short and long daylength were mostly reproductive, while those reared under decreasing daylength were most likely to be in diapause. Therefore, she concluded that it is the change in daylength that is an important cue, rather than absolute day length (canada’s butterfly migration is largest on record).
Monarchs use a sun compass or magnetic compass to find overwintering sites. Sun compass is the celestial cue that is most likely used in pointing the way to the overwintering sites. Monarchs may use the angle of the sun along the horizon in combination with an internal body clock (like a rhythm) to maintain a southwesterly flight path.
A magnetic compass is an addition to a sun compass or as a “back up” orientation guide on cloudy days when they cannot see the sun. Studies of migratory birds have indicated that they register the angle made by the earth’s magnetic field and the surface of the earth. These angles point south in the Northern Hemisphere and north in the Southern Hemisphere (canada’s butterfly migration is largest on record). But the magnetic compass and the sun compass is only a theory. A scientist says, “If they (monarchs) are using the sun as a proximate orientation mechanism and you shift them six hours, you should shift them ninety degrees in their orientation,” Taylor explains, “and that’s what happened in the experiment.
We shifted them and got the response we expected. Instead of flying, as the control group did, at 210 degrees, the time-shift butterflies flew off at about 280 to 290 degrees.” The next task is to figure out how the butterflies are using the magnetic field. “We know at this point from our unpublished data, that they do respond to electromagnetic pulses,” Taylor says. “That is really the first step in establishing whether or not they use the electromagnetic field.
“What that theory does not explain is why along the migration route about the time the butterflies enter Mexico they change their course dramatically. “Most of the data is consistent with the idea that they are using the magnetic field in some way,” Taylor explains. “However when they reach the mountains of Mexico, they move along the mountains in a way that is totally inconsistent with using the magnetic field.” Basically, the butterflies veer off course and make a left turn. Researchers believe that at that point the butterflies switch navigational tools from the earth’s magnetic field to land forms. If they were to continue on their original course, they would end up in the Pacific Ocean, where there is no food source. By following the mountains, they take a course with plenty of food that leads them to the same roosting sites their great-great grandparents left six months before (ebscohost.
com).The biggest recorded migration was 300 million red admiral butterflies from Windsor to New Brunswick, more than ten times what would be seen in a typical year. Numerous other butterfly species have also arrived or appeared in greater numbers. Kerr said, the first local butterflies (the ones that overwinter in canada) were seen as early as March and southern Ontario was hit by the first wave of butterflies in mid april, thanks to strong winds. The red admiral moved so far north so early that they flew into areas with snow, something that normally wouldn’t happen. A second wave arrived in May, boosting the diversity in southern Ontario, especially from Windsor to Toronto. Kerr said one enthusiast recorded 22 different species in a single Windsor park (canada’s butterfly migration is largest on record).You can track monarchs by twitter and there’s also trackers online.
Monarchs have a sticker on their wing that people know where they started from or where they have been. Anyone can tag a monarch the stickers are online. There are classes you can take that shows you how to tag a monarch.
The sticker is made up from thin plastic and you put it on the underside of the monarch’s wing. Butterflies have a insect social security number that they track. The Monarch Monitoring Project warns about releasing monarchs because it can mess with research and it’s against bringing monarchs across state lines.
Twitter allows you to check butterfly sightings and offers a timely feed on monarch news. The wind map shows which way the winds are blowing, for those that track monarchs they can tell where the monarchs will be going. If the winds are coming from the south that means the monarchs won’t be moving much so people can go tag them and record where they are. There is a monarch watch facebook page, there are 23,000 fans on the facebook page. They share information, photos and all about their migration.
The butterflies also have a monarch watch website. This site shares information on how to tag a monarch, raising milkweed, rearing monarch caterpillars and a database with all the monarch tags recovered in Mexico, so for those of us who tag can find out if any of our butterflies made it home. The site also post predictions for when the peak migration will occur at your latitude based on monarch watch scientists (texasbutterflyranch.com) Butterflies traveling south congregate on peninsulas. The shape of the peninsula funnels the migrating butterflies. At its tip, the monarchs find the shortest distance across open water.
They congregate along the shore to wait for a gentle breeze to help them across. The range of the monarch is worldwide and while monarch butterflies are not endangered as a species, the migration of the eastern north american population may be an endangered phenomenon. The media consistently reports that the monarch is endangered of becoming extinct and have been criticized for exaggerating. Reports of the monarch becoming extinct by the media have been criticized by scientists (omicsgroup.
org).Many butterflies have a single plant required as a food source for their larval form called a host plant. Milkweed is the host plant for the monarch butterfly. Without milkweed, the larva would not be able to develop into a butterfly.
Monarchs use a variety of milkweeds. Over 100 species of milkweed exist in North America, but only about one fourth of them are known to be important host plants for monarch butterflies. Every backyard can become an oasis for monarchs and other pollinators, even in cities. Schools, youth and community groups, businesses and state and local governments can engage in planting native milkweed and protecting monarch habitat along roadsides, rights of way, and other public and private lands. Whether it’s a field, roadside area, open area, wet area, or urban garden; milkweed and flowering plants are needed for monarch habitat. Adult monarchs feed on the nectar of many flowers, but they breed only where milkweeds are found. The easiest way to grow milkweed is to sprinkle some seeds around in the fall after a killing frost and wait for spring.
The seeds experience winter and know when it’s time to get growing in spring. You can also grow milkweed indoors. If you want to have larger plants for the beginning of the growing season, you’ll need to start some plants inside. It is also more predictable. If you grow them inside you need to trick the seeds into thinking they have been through winter because you need cold stratification for growth and germination. It’s easy to fool the seeds all you need to do is put them in a wet paper towel, put them in a bag and put them in the refrigerator for three to six weeks.
After that you’ll want to start planting them (growing milkweed). Milkweeds- along with the nectar plants monarchs need to fuel migration—have fallen prey to changes in midwestern farming practices. The most detrimental has been development and increased planting of corn and soybeans genetically engineered to survive applications of the herbicide glyphosate, or Roundup. Then near ubiquitous use of “Roundup Ready” crops today allows farmers to apply the herbicide widely, killing off milkweed and other native plants that once thrived between crop rows and along the edges of millions of acres of agricultural land. Milkweed losses also have been driven by the massive conversion of grasslands, rangelands and former conservation reserves to monocultures of corn and soybeans—a change propelled in large part by federal pressure to develop ethanol as an alternative fuel. Taylor reports that since 2007, farmers have plowed under more than 24 million acres of new cropland, an area about the size of Indiana.
“In much of the Corn Belt, farming is now from road to road, with little habitat for any form of wildlife remaining,” he says. As monarch populations plummet, “other threats are becoming proportionally more significant,” Oberhauser says. She cites disease, predation in the butterflies’ winter roosts, insecticide use and invasion by nonnative plants related to milkweeds. Monarchs lay eggs on these plants, called swallow-worts, but their caterpillars cannot eat the leaves and die (ebsco.com).One task force, led by U.S. Fish and Wildlife Service Director Dan Ashe, focuses on monarchs, and the service is reviewing a petition to list the butterfly as threatened under the U.
S. Endangered Species Act. Meanwhile, dozens of nongovernmental groups—including NWF—are mobilizing members and partners nationwide to restore milkweed and native nectar-plant habitat for monarchs.Will such efforts be enough? “The scale of habitat loss is so great that we’ve only just begun,” Jepsen admits. According to Taylor, one million acres of milkweed must be planted annually simply to keep pace with new losses.
Creating all the habitat monarchs need, he adds, “requires the largest habitat-restoration program ever attempted in the world.” Still, he and other scientists believe it is doable—with sufficient will, collaboration and long-term financial commitment. “There is no reason to lose the monarch migration,” Taylor says.Did you know milkweed is poisonous? The white milky sap in milkweed is what makes it toxic, this sap is all throughout the plant. But not all species of milkweed are poisonous. Those that are the levels are different. Asclepias Syriaca is a broad-leafed milkweed, it’s said that the broad-leafed milkweed are more toxic than others. Asclepias Syriaca produces cardenolides.
These toxins affect the heart, many plants contain this toxins. Since monarchs feed on milkweed in all stages of life. The toxin provides a defense for them because birds or other animals often die from the toxin (uwlax.edu). The monarchs that spent winter breeding on tropical milkweed were infected with OE at levels five times higher than those that migrated.
Yet researchers found no difference in OE virulence between migratory and nonmigratory populations. Because OE infection often results in deformed wings, shorter lifespans and decreasing breeding. Monarchs for going winter migration could experience serious health effects and possibly spread disease to migrating monarchs as they cross paths. Still, researchers stressed importance of providing monarchs with milkweed habitat, which is being lost. Year around access to milkweed in the Southern U.
S. might be increasing the risk of disease, they encourage either replacing tropical milkweed with native varieties or pruning that exotic plant in winter (weeding out disease pg.7). Long distance migration can lower parasite prevalence if strenuous journeys remove infected animals from wild populations. Researchers collected monarchs from two wintering sites in Central Mexico to compare infection status. On average uninfected monarchs had lower values than parasitized butterflies, indicating that uninfected butterflies originated from more northerly latitudes and travelled farther distances to reach Mexico. Within the infected class, monarchs with higher quantitative spore loads originated from more southerly latitudes, indicating that heavily infected monarchs originating from farther north are less likely to reach Mexico. We ruled out the alternative explanation that lower latitudes give rise to more infected monarchs prior to the onset of migration using citizen science data to examine regional differences in parasite prevalence during the summer breeding season.
We also found a positive association between monarch wing area and estimated distance flown. Collectively, these results emphasize that seasonal migrations can help lower infection levels in wild animal populations (ebscohost.com).
Breeding habitats have a profound effect on migration of large numbers of monarchs. The single most influential factor is the weather. Ideal habitats promote the migration of large numbers of migrating monarchs. Summer habitats provides ample nectaring plants for the adults and abundant, healthy larval plants. Low populations of predators and parasites will also allow for more monarchs surviving into adulthood. A low prevalence of disease will improve the survival. Monarchs breed the fastest within a specific temperature range. An increase of the range of the breeding population is another indicator that the habitat is conducive to reproductive success.
In the fall in North America the ideal breeding habitat changes in late summer. The migration begins and the ideal habitat required for successful migration changes to a ‘corridor’ (to Mexico) of available nectaring plants, optimal temperatures, tailwinds and low precipitation. The butterflies must also remain hydrated. An early frost will kill migrating butterflies. The ideal habitat for monarchs in winter exists in their overwintering sites. The factors influencing the habitat include, the condition of the forest canopy, precipitation, predation, availability of suitable trees on which to roost, sources of water, the ideal temperature range, sunlight, lack of rain and ice and human activity near the sites.
Roosting butterflies have been observed to roost in sumacs, locusts, basswood elm, oak, osage orange, mulberry, pecan, willow, cottonwood, and mesquite. If conditions are too hot in the overwintering sites, the butterflies will use up their fat reserves and not survive until spring. High temperatures initiate reproductive behavior with the possibility of the butterflies leaving the overwintering areas to early while it is still too cold in the north to stimulate the emergence of food plants and nectar plants. In the spring The ideal habitat for monarchs migrating north from Mexico sites to Texas and Oklahoma is less studied. Presumably, tailwinds assist the migration north.
Rainfall is critical in creating the ideal habitat for the returning monarchs which must have abundant, lush and healthy food plants available for larvae. Ideal growth of larval plants that emerge in succession as the breeding butterflies migrate north, is also critical. Drought is a big factor influencing the emergence of food plants (omicsgroup.org).Since monarchs cannot stand the winter they migrate south and west each year. The monarchs travel in the spring and fall. They cover more than 2,000 miles to get to their destination. Even though the sun compass and magnetic compass is just a theory scientist believe that they use these two to travel and so they know where to go.
The biggest recorded migration was 300 million butterflies that traveled from Windsor to New Brunswick. You can pretty much track a monarch anyway you want. There ‘s a ton of sites and social media that shares butterfly migration information, photos and plenty more. Most insects have a host plant, the monarchs have milkweed. Milkweed can be grown anywhere from your home, garden, field and on the side of the road.
The problem we now have is we don’t have enough milkweed for the monarchs or butterflies in general because of the chemicals farmers put in their fields before the plant their crops. The butterflies need that to travel, that’s their fuel. It no longer grows on the side of the road because crops are from road to road. Some monarchs get diseases if they don’t travel long enough. Therefore it’s spending everywhere.
Breeding habitats go off of the weather. The habitats need low populations of predators and parasites so the monarchs can grow into adulthood, low prevalence of disease and the right temperature. The ideal habitat for monarchs in winter in overwintering sites include: the condition of the forest canopy, precipitation, predation, which trees are available, sunlight and how much ice and snow they get. For the returning monarchs rainfall is critical and they need host plants for the larvae. We covered all the information about monarchs, the history, migration, habitats and disease.