Answers From the Monarch Butterfly Expert
Spring 2012
(Back to: News Update | Teaching Suggestions | Q & A )

Special thanks to Dr. Karen Oberhauser for sharing her time and expertise again this year to answer readers' questions.

Have you ever wondered:

  • Where a female goes after she lays eggs in your garden?
  • Which nectar plant is the most popular food for monarchs?
  • Why isn't the word monarch capitalized?
  • If you can put nectar out for monarchs, like hummingbirds?
  • How to protect yourself against ticks in the field?
Teaching Suggestions
Teachers: You can use today's Answers from the Expert in the activities suggested in "Learning from Experts."

Dr. Karen Oberhauser

Dr. Karen Oberhauser
Professor at the University of Minnesota. Director of the Monarch Larva Monitoring Project and Monarch Lab.

From California:

Q: Is there a specific term used to describe the time period when monarchs are spending the winter in Oyamel, Mexico's forests?

A: I use the term overwintering. Some people say wintering. Others say hibernation, but I don't really agree with calling this period hibernation, since it is not a true hibernation.

From Ontario:

Q: When should I plant milkweed seeds? I have some milkweed seeds that I wish to plant in preparation for the arrival of the monarchs. When should I plant them, indoors and outdoors? I live in Toronto, Ontario, Canada on the north west shore of lake Ontario.

A: You could either start the seeds indoors, where you'd get a bit of a jump start on natural growth, or you can put them outside in flats or pots, or just scattered in your garden so they can start naturally.

From Texas:

Q: Last season we had many tachinid flies that impacted our local Monarch caterpillar population. Is there anything that can be done to keep that from happening again?

A: Tachinid flies are a natural part of monarchs' habitat, and there's really nothing you can do about them. If you collect the larvae and rear them inside, you are decreasing their exposure time, but this doesn't have a large effect on a population-level scale. If you're interested, please report your rearing outcomes to the Monarch Larva Monitoring Project – we're very interested in documenting parasitism rates throughout the country. Feel free to contact me with questions about how to do this; you'd need to report both the ones that are parasitized and those that aren't. You can read about the flies at (see Activity #3), or contact me at

From Illinois:

Q. When a female lands in my garden and deposits eggs on the milkweed in mid-May, what happens to her? Does she die right away or does she continue her journey north? Does she stick around for a few days?

A. Great questions! The answer depends partly on how old the female is, and what the landscape is like around your garden. If she's quite young, she may continue northward; females that leave the south and get to your area in mid-May are part of the large movement northward. But, she may be from an egg that was laid in early-mid March, and could thus be nearing the end of her life. Also, if your garden is an oasis in a suburban desert of grass, roads and parking lots, she might be more likely to stay because there is no good habitat.

Q. And when her offspring are born in mid-June, do they stick around my yard or do they fly north? It's hard for me to tell who is staying and who is coming and who is going!

A. As for the offspring in mid-June, we really don't know. If you have monarchs throughout the summer, I'd guess they may be local, but they could also be coming up from the central part of the country.

From Texas:

Q: As you are aware, Texas has been hard hit by drought which has decreased our milkweed. Is it possible to make supplemental feeding stations? I live in North Texas near Sherman,Tx and we are on migration track. Would love to help so any info would be appreciated.

A: I'm always in favor of planting native milkweeds wherever you can to help out monarchs, with the caveat that it's probably not a good idea to plant it near overwintering sites. But since you're in Texas, that isn't an issue. I would avoid planting too much non-native, tropical milkweed, since there's evidence that the presence of milkweed during times that it's not normally available could influence their migration patterns.

From Delaware:

Q: What could we put out for Monarchs before flowers bloom? Nectar, as for hummers? Fruit?

A: You probably won't see too many monarchs before flowers bloom. They can find dandelions, lilacs, maple flowers, and other early blooms. I have used hummingbird feeders in cages sometimes, but have only seen a few wild monarchs at feeders. You could try fruit too, but it spoils pretty quickly.

From Texas:

Q: We grow an abundance of butterfly weed in our flower beds. They look great this year because we didn't freeze. They also multiply everywhere. We always have a lot of monarch caterpillars but rarely see chrysallis. We have a lot of trees in our yard also. I never see chrysallis there either. Where do they go after leaving the butterly weed. Should I put up a fence in my flower bed and cover with cheesecloth to ensure the chrysallis formation?

A: It's really hard to find monarch chrysalids (or pupae). Also, there is very high mortality throughout the larval stage, so you'll always see more eggs and larvae than pupae. They might be going to your trees, or to other plants in your yard. You can definitely try the cheesecloth; I'd be interested in hearing how it works.

Q: We had about 15 monarch caterpillars this winter in the flower bed. Every time they made a chrysallis they died. I would like to build a shelter to bring indoors with butterly weed in it to allow them to become butterflies. Is that possible?

A: Yes, it's possible. Here are some instructions for rearing monarchs indoors.

From Saskatchewan:

Q: Is there such thing as an albino Monarch butterfly/caterpillar? Would they taste different to predators?

A: There are white monarchs, which are fairly common in Hawaii. However, they're not true albinos because they still have the black lines on their wings. There are also larvae that are missing the yellow stripes, and are only white and black. I studied the larvae in my lab several years ago. I don't know how they taste to predators.

From Michigan:

Q: Why isn't the word monarch capitalized?

A: Some people do capitalize it; it's just a matter of preference. Some people capitalize bird names, and other people don't. You can choose; in my experience, most scientists don't capitalize the common names of species. I don't capitalize monarch, or robin, or bluejay, or human, or dog, or raccoon, or house fly. But, I do capitalize proper names that are part of species names, like American robin, Henslow's sparrow, or New England aster.

From New Brunswick:

Q: What is this year's population estimate for eastern monarchs?

A: The numbers just came out from the Mexican overwintering sites. The population this year covered 2.89 hectares, which is the third lowest value since monitoring started in the 1993-1994 winter.

From Vermont:

Q: How do you protect yourself from deer ticks/Lyme disease when you're in the field?

A: I don't worry about looking like a complete nerd. Since the deer ticks are already (on March 16!) out in full force in Wisconsin, where I spend a lot of time in the field, I've already had practice this year. I wear long pants, and tuck the pants legs into my socks. I tuck my shirt into my pants, and wear long sleeves. I constantly look for ticks on my legs and arms, and check myself thoroughly when I'm back inside. I don't ever use insecticides, since I'm worried that it will affect the insects I handle.

From Maryland:

Q: Which nectar plant is the most popular food for the Monarch butterfly?

A: Monarchs nectar from many flower species, and their favorite species vary a great deal because different nectar flowers are available at different times of the year and in different locations. They generally like yellow and purple flowers, but also use red and white flowers.

From Vermont:

Q: What kinds of questions might the sequencing of the monarch genome help scientists answer?

A: The possibilities are endless! First, sequencing the monarch genome can help us understand monarch butterfly migration. We'll be able to see what genes are turned on during the migration, and will be able to understand the genetic differences, if any, between migratory and non-migratory populations. We'll also be able to compare the genes involved in monarch navigation with those used in other long-distance migrating species. Genome work could also help us understand behaviors like mate choice, host-plant choice, or the relationships between monarchs and other butterflies.

From: Michigan:

Q: Do male Monarchs migrate north from Mexico?

A: Yes, the males migrate too. While females do sometimes mate in the Mexican colonies, they usually use sperm from the last male that they mate with, so it's to the males' advantage to move north with the females.

Q: Can butterflies hear sounds?

A: In general, butterflies have very poor hearing. They can often sense sound through veins in their wings, but this has only been studied in a few butterfly species. Larvae can sense sound through small hair-like projections on the surface of their bodies called tactile setae. The setae sense vibrations in the air.