From the Monarch Butterfly Expert
Special thanks to Dr. Oberhauser for providing her time and expertise in responding to your questions below.
From: Greensboro, North Carolina
Q: Last August 24th a Monarch laid eggs on common milkweed in my yard. Other years we have had egg laying in July and August with much less in the earlier summer months. Maps don't show North Carolina as a late-summer egg-laying area. Are these monarchs early migrants on their way to Mexico or are they the next to last summer generation venturing south?
A: We are
documenting more and more monarch egg-laying in southern states in the
late summer through the Monarch Larva Monitoring
Project and other observations. If you go to the results page of this
site and click on your state, you’ll see that other people are seeing
the same thing. The monarchs laying these eggs are moving south, perhaps
to escape coming cold temperatures in the north, but are very unlikely
to get to Mexico.
From: Saylorsburg, Pennsylvania
Blue Ridge Homeschool Group
Q: We have questions about the Monarch population, after studying the graph in the March 3 update. Why was the population/area covered so low in the winter of 04/05? Why was it so high in 96/97? Why hasn't it recovered, to be close to the levels from the mid 90's? Augustin Cavalier, age 7, homeschool student and mother Nina Cavalier
A: There are many reasons that we think the population was so low in 04/05. These include winter storm mortality during 03/04, a cold and wet summer breeding season in 2004 that led to fewer monarchs being produced, and habitat deterioration in Mexico and the US. Luckily, the population did rebound somewhat in the winter of 05/06, but many monarch biologists are concerned about the extremely dry conditions in Texas that these monarchs will face as they head back north.
From: Perrysburg, Ohio
Q: These three questions are based on a dead monarch that was found in our town of Perrysburg, Ohio in January. Do butterflies decompose? We are surprised that after two months of being in our classroom, the colors on its wings are still very vibrant and the body intact.
A: If the butterfly is dry, it will last a long time without decomposing. There are insects in collections that are over 100 years old!
Q: How did the butterfly get to Northwest Ohio in January? Is it possible that the chrysalis was formed late in the fall and it opened up during our mild January weather?
A: My guess is that this was an erroneous report! Unless you had mild weather in November and December, the chrysalis would have been killed outside. They can’t stand long periods of extremely cold temperatures in any life stage.
From: Ferrisburgh, Vermont
Ferrisburgh Central School
How fast can a monarch fly? How do they know how to find a good air current
that will take them in the right direction? Erik Grade Three Ferrisburgh
From: Dallas, Texas
Episcopal School of Dallas
Q: Karen, I am a first grade teacher at the Episcopal School of Dallas in Dallas, Texas. For the past 15 years we have been raising and studying monarchs in the classroom. Thank you for the wonderful resources in your book. My question is this: Each August, September, I find monarch eggs and caterpillars on my garden milkweed. If the migrating monarchs do not mate where are these caterpillars coming from? I do not see local monarchs during the summer. The first I see seem to be the migratory ones in late August. Thank you for what you do. Lee Hammons
A: Hi Lee! I’m glad you like our book. I’m going to refer you to my first answer above to the student from North Carolina. This pattern is very pronounced in Texas (see www.mlmp.org) and we would love it if you would join the Monarch Monitoring team and report your garden observations!
From: Texarkana, Arkansas
Vera Kilpatrick Elementary
Q: Why have so many monarchs appeared in the state of Arkansas this early in the spring when there is little or no milkweed available for egg laying?
A: We don’t know. This seems maladaptive, but it is possible that there is milkweed available in places you aren’t looking. They may also have stayed in Texas through the winter, and are moving north; we’re seeing some monarchs throughout the year in Texas where people are cultivating tropical milkweed.
Q: Why do some of the monarchs we are seeing in southwest Arkansas appear to be worn and faded and the others appear to be almost brand new? Could some of them have over wintered through our mild winter, much like they do in Mexico?
A: It is likely that worn monarchs you’re seeing have either come from Texas (see my answer above), or they could have left Mexico early. Since I’m not sure when you wrote this question, I don’t really know the timing of your observations.
From: Ontario, Canada
I live in a rural setting and it is always pretty windy. What can I do
to attract monarchs, in particular, or all other species of butterfly?
From: Soldiers Grove, Wisconsin
Are there any Monarch butterflies on Maui, or any of the Hawaiian Islands?
If so, which island and what time of year?
From: Katy, Texas
Cinco Ranch High School
We have noticed that there are monarch caterpillars on our butterfly bush.
We already have eleven! (Today is March 13th.) Why are monarchs reproducing
now? Will the adults that develop from these caterpillars make it to Mexico
From: Torrance, California
St Catherine Laboure
Q: The cocoon is exquisite. How does the butterfly spin a green lantern with golden dots precisely placed?
A: First, butterflies don’t make a cocoon; a cocoon is a silken covering made by some moths to cover their pupa. The green coloring of the monarch pupa, or chrysalis, is the actual skin of the monarch during this stage.
From: Mexico City, Mexico
Q: Dear Karen, My name is Arturo Velez, from Mexico. My question is: Has anyone discovered the Monarch's main migratory route INSIDE Mexico? Every time I see a migratory map I wonder which villages and towns they fly through during their long trip. Thanks! Arturo
A: Arturo, this is a wonderful question! We actually know very little about the paths that the monarchs take through Mexico on their way to the wintering sites in the Fall, or back from the sites in the Spring. Maybe you can help us figure that out!
From: Houston, Texas
Q: What is a good estimate of the average number of Monarch butterflies that die while overwintering in Mexico (without incidence of a major disaster such as the big snow storm in 2002)and are deducted from the number of butterflies that will make it as far as Texas during the journey north in the spring? Thank you! Sincerely, The students and teachers from Hairgrove Elementary in Houston, Texas
A: This is a hard one to answer, since it’s difficult to count either the dead butterflies or the living ones. We think that about 20-25% of them die, barring major disasters. Most important causes of mortality are bird and mouse predation, desiccation (drying out) and starvation.
From: Waite Park, Minnesota
Kimball Elementary School
Q: Why did so many of our caterpillars die this last fall from the monarch lab...we only tagged 25 of our 200 we received and were really sad...........we washed hands, etc. to avoid parasites but can't figure out what it was. Thanks, Karen. Hope all is well with you. Did you go to Mexico this winter? Paulette Hauge 6th grade teacher at Kimball Elementary School!
A: Hi Paulette! I did go to Mexico this winter, and was thrilled to see that the colonies were larger than they were when I was there last year. It was an amazing trip, since I was there just before they left for the US, and were, therefore, very active.
We did have
problems in our lab last year, and you should receive our newsletter with
a discussion of this very soon. Here is a brief summary: We have come
up with two possible reasons for this. The first is a microsporidian disease
called Nosema. This is a widespread group of organisms that are found
in many insects, and there is a group within them that infects Lepidoptera.
They are spread very easily, and are extremely contagious. We’re
not sure where the infection came from, but it is sometimes used as a
biological control agent to combat insect pests, like corn borers and
gypsy moths. One report said that Nosema is sometimes used to control
greenhouse pests, and may have even been in the potting soil that we used.
The second possibility is something called nuclear polyhedrus virus (NPV),
which would cause them to turn black and sort of gooey. This is also used
as a biocontrol agent, and is airborne and especially common in the fall.
From: Hinckley, Illinois
Q: How do the Monarchs survive in Mexico?
A: They store up a lot of fat in their bodies that they can use to stay alive all winter, since they don’t have much or any food in Mexico. Also, the cool temperatures there slow down their metabolism so they can stay alive longer than they would up here in the summer.
Q: Where do they sleep and what do they eat?
A: They sleep on the trees, and, as I said above, eat little or nothing. There are some flowers near the colonies, but nowhere near enough for all of the butterflies. They do need to drink water though, and depend on streams in and near their winter sites.
Q: How do they know when it is time to come back?
A: We think they can tell by the day length when it is time to leave for the United States breeding grounds.
A: The number of questions about early monarchs in the south makes me suspect that there are more this year than in past years. I’d be interested in hearing if you think this is true!
There are two ways to tell; one is not definitive, but doesn’t result in dead monarchs, and one is definitive.
First, you can surmise where they came from by the timing of your observation. If you see them in February or early March, it is very unlikely that they migrated from Mexico and more likely that they are the offspring of butterflies that wintered locally. If you see them later, especially if you haven’t been seeing monarchs for several months, you can surmise that they re-migrated from Mexico.
You can also analyze the monarchs to see what kind of milkweed they ate when they were caterpillars, but this requires killing them and having access to specialized equipment. If they ate common milkweed or other northern species, they are migrants, since they must have been larvae in the northern part of the United States or southern Canada. If they ate local Texas species, they are the offspring of butterflies that laid eggs in Texas. This is the technique used by Stephen Malcolm and his colleagues to determine how monarchs re-migrated into their northern breeding ranges – if they flew all the way from Mexico to the north, or if they had an additional generation in the south before getting all the way north.
From: Glen Ellyn, Illinois
Forest Glen School
Q: About how many monarch butterflies are there in the United States? Thank you. We are a first grade classroom in Glen Ellyn, Illinois.
A: This would be very difficult to tell with a great deal of accuracy, and would depend on the time of year. At the end of the summer, a good estimate of the number east of the Rocky Mountains is probably almost a billion. If you included the monarchs west of the Rocky Mountains, the number might go up a few million or so.
Q: How many
years have you been working with butterflies?
Q: How many years do butterflies live?
A: Monarchs that migrate live about 6 to 8 months. Those that don’t migrate live about one month.
Q: What is your favorite question people have asked you over the years?
A: It would be hard to choose my favorite question. My favorite kind of question is one that I don’t know the answer to, because it makes me think about new things about monarchs! After 22 years, it’s nice to think about something new. Your question about the number of monarchs in the United States really made me think!
From: Seattle, Washington
We are located in Seattle, Washington. We have classes participating in
the Tulip Program and the Whooper migration. I have checked the open spaces
around our school, and can't find milkweed plants. My question is; if
we raise milkweed, and raise the caterpillars, will Monarchs fly south
to Mexico? We have not witnessed a monarch population in Seattle. How
would they "know" where to migrate?
Q: We are very familiar with salmon migrations and the "cues" they get to return to their spawning grounds but they are a higher order species and they spend considerable time in their hatching environment. If monarchs were raised in a non-traditional area where would they migrate when they leave Mexico? Does food availability serve as the primary "cue" and would they follow the food source?
A: I’m not sure that I would consider salmon a higher order species than monarchs. Both have evolved over many eons, and have adapted to fit their particular environmental niches extremely well, or they wouldn’t be around. Monarchs don’t learn how and where to migrate, but it’s almost more amazing that they have the right instincts that allow them to carry out this amazing migration with no learning. Thus, a monarch put into the winter colonies would probably be able to migrate appropriately, although this has never been tested, to my knowledge. We don’t know if food serves as the primary cue for spring re-migrants.
From: Duntroon, TX, New Zealand
What is the gold for on the chrysalis and how does it turn black? Baeley/Jack
some hypotheses for the reasons that these butterflies have metallic-looking
spots on their pupae:
From: Lowville, New York
Q: I allow milkweed to grow in my butterfly garden. Last year the milkweed became very dark and sticky. I couldn't find one single caterpillar on the milkweed. Could you tell me what happened to it so I can avoid the problem this year?? Thank You Cherie Brigham
A: I have no idea what happened to your milkweed; I’ve never seen this before. It sounds like some kind of a fungus.
From: McLean, Virginia
Spring Hill Elementary
Karen, I was on the tour with Bill Calvert from March 4 -11 and was thrilled
to meet you. I have shared my trip with all my students and these questions
come from that sharing. I don't know the answers. Thanks! If monarch butterflies
can die in a puddle of water why don't they die when it rains?
From: Lake Elmo, Minnesota
Lake Elmo Elementary
Q: Dear Dr. Oberhauser,
Did you find out how the caterpillars got the disease that killed our caterpillars last September? Where did it come from? How did it get into the lab? How did our caterpillars catch it? Will the caterpillars next year be OK? Was it an insect? Did it cause all the caterpillars to die? Were our cages clean, and how did they catch the disease? Was it something they touched or ate? Did they catch it here at our school or did they catch it at the lab? How many caterpillars got sick? Mrs. Frederick's Kindergartners at Lake Elmo Elementary
A: Hi Barb and Lake Elmo Students! Another good friend of mine from Minnesota, Paulette Hauge, asked the same question, and I’m going to refer you to her answer above to save space on this long list of questions. And I’m going to forward this file to De so that she can answer your last question!
Q: Question for De: When De was here she said we could make new milkweed from the tropical one we have. It is almost as tall as Mrs. Frederick. Do we cut it at a special place? Do we put it in water or in dirt?
to Mrs. Fredreck’s lovely Kindergarteners! Yes, new plants can grow
from “cuttings” of old plants, especially if they’re
as tall as a teacher! Now that spring has arrived, and the days are getting
longer (…more light!), it’s a GREAT time to try this in your
classroom. Cut the stem(s) into approximately 12 inch lengths, and remove
any remaining leaves from the bottom half of the stalk. Place the stalks
in a container of water on your windowsill. Roots should sprout from the
places where leaves previously grew. Once you have a lot of little roots,
plant your cutting in soil. And don’t forget to keep watering the
original plant. It will sprout new growth from the places you cut. Good