Answers From the Monarch Butterfly Expert
Spring 2010
Special thanks to Dr. Oberhauser for providing her time and expertise in responding to your questions below.
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| Dr. Karen Oberhauser | ||
From: Virginia
Q: How old were you when you started to get
interested in monarch butterflies?
A: Ten.
From: Wisconsin
Q: How many miles do individual monarchs migrate?
A: The distance varies a lot, probably on average
about 1500-2000 miles. You can look at map and make some estimates yourself
– try measuring the distance from northern Maine to the wintering sites
in Mexico. This would be one of the longer distances.
Q: Why are they called "monarchs?"
A: Nobody really knows this for sure. It’s possible
that monarchs were given this name because they are so large and majestic. But
the name may have also come from King William III (from England), who was
called Prince William of Orange (get it?) before he became king.
From: Texas
Q: Is there a fungus that affects the chrysalis? I
have had problems losing several chrysalis. They just turn black. Also, during
the process some caterpillars just hang and die.
A: There are many diseases and parasites that kill
monarchs, including viral, protozoan, fungal, and bacterial infections. These
often kill the caterpillars just before they pupate, or during the pupa stage.
If you’re having a lot of problems with this, you might want to consider
rearing them in separate containers to see if you can avoid this problem in the
future.
Q: What type of bug is red and black and loves to
be on the butterfly weed?
A: Milkweed bug or milkweed beetle – try
looking these up on-line and seeing which it is you have. I recommend the book
Milkweed, Monarchs and More for descriptions of many of the cool things you can
find on milkweed plants. You can order it from the MonarchLab store.
From: Tennessee
Q: On the crysalis at the lower edge of the top
region is a ring of gold dots. Of what substance are these composed? Do they
have any special function?
A: Fred Urquhart first studied the gold spots on
monarchs in the 1970s. He felt that the spots were involved in the distribution
or formation wing scale coloration. However, the experiments that he did
involved cauterizing the gold spots on the pupa, and it is possible that this
process may have damaged the underlying tissue and affected the color patterns.
Interestingly, all /danaine/ butterflies (monarchs and their relatives) have
metallic spots on them. A group of researchers in Germany did a careful study
of the properties of these spots. They are not metallic (so they aren't really
gold), but the cells reflect light like metals do, giving them the appearance
of being metallic. Other danaids have silver, copper, or gold spots.
Here are some hypotheses for the reasons that these
butterflies have metallic-looking spots on their pupae:
a) camouflage they could reflect colors of the surroundings and break up the shape of the pupa; they might also look like dew droplets.
b) Warning coloration
c) Filtering particular wavelengths of light which might be harmful to the monarchs
d) They might not have any function, but just be the result of something else in the cuticle of the insect.
From: Wisconsin
Q: Is
there a Monarch generation that doesn't migrate (either north or south) away
from where it emerges? Have tagging studies during the summer months shown that
at a certain latitude and date range Monarchs stay where they are for their
entire butterfly life?
A: Migration is defined as directional movement, so monarchs could move quite far from where they emerge, and still not be migrating. "Conventional wisdom" is that monarchs that emerge in the northern part of their summer range (i.e. north of the southern part of Lake Michigan, or so) in June or early July don't move far, at least in a directional way. It is difficult to do tagging studies during the summer, because monarchs are not concentrated in a single area. However, I did some work on this many years ago, and caught many adult monarchs (especially males) at roughly the same location over several weeks. There is a description of the different monarch generations, and where we think they go (or don't go) at this link.
From: Pennsylvania
Q: Is any work being done on making more efficient
cook stoves in Mexico? We read about families around the sanctuaries
using the trees for firewood. This year we corresponded worked with a Peace Corps volunteer in
Senegal who helped the people there plant trees and make efficient cooking
stoves.
A: Yes, there is a wonderful organization named
Alternare in Mexico that is doing exactly what you suggest. The Monarch
Butterfly Fund (www.monarchbutterflyfund.org)
supports Alternare with annual donations to support this work, if your class
would like to make a donation to help with their work.
From: Oklahoma
Q: My last years pupae turned black as if they'd
been charcoaled..most died....almost no survivors last year.. some were
tachinid caused.. this was new to me...we had 9 weeks of rain prior to their
arrival.. could rain have caused a virus which caused this problem?
A: There are many diseases and parasites that kill
monarchs. It’s possible that your problems were linked to rain, but also that
some viral, protozoan, fungal, or bacterial infection got into your monarchs
and spread from one to the other. If you aren’t already doing this, you might
want to consider rearing them in separate containers to see if you can avoid
this problem in the future.
From: Massachusetts
Q. How are the monarchs doing after the big floods and landslides in Western Mexico?
A: The Journey North and Monarch Watch websites have lots of good information
on the effects of the floods near the monarch wintering sites in February, as
does our 2010 Monarch Larva Monitoring Project newsletter. In short, the heavy rains probably killed many
monarchs. It’s going to be very important to monitor monarch numbers this
summer to see if there are lasting effects.
From: Illinois
Q: I understand that monarchs migrate to Mexico -
from both sides of the Mississippi River. From what I know they fly to Mexico
and then return. I am confused because I understand that the life span of the
Monarch is very short. How can a monarch migrate when its lifespan is so short?
A: The generation that migrates lives up to 7-8
months. Read about the different generations at this link.
From: Ontario
Q: I have been asked to officiate at someone’s marriage ceremony and I would like to obtain several butterflies to be released at the ceremony which will be a garden wedding. How would I go about this?
A: I recommend against using living organisms as
ceremonial trinkets, unless the act of releasing and raising them has special
meaning or educational value to the individuals involved. Purchasing the live
butterflies doesn’t provide much educational value, nor does it really benefit
the butterflies.
From: Texas
A: In 2002 and 2004, winter storms killed up to
60-80% of the monarchs in some of the colonies.
Q: Is the monarch migration threatened as a
phenomenon?
A: Yes, monarch migration is officially listed as a
threatened phenomenon by the IUCN.
Q: Why are the Mexican government and the
international NGO's unable to protect the wintering habitat of Monarchs?
A: This is a very complicated problem, and one that
is not unique to the monarch wintering sites. All over the world, biologically
important ecosystems are being lost at an alarming rate to human uses. A lot of
the lumber from these sites probably ends up in the US, in things like avocado
packing crates. Recent studies have shown that most of the illegal logging in
these sites is done by logging companies, not by the local people, and that
existing laws are not being enforced effectively. If this is something that
really interests you, I recommend this paper, which you can find online:
Honey Roses, J. 2009. Disentangling the proximate
factors of deforestion: the case of the Monarch Butterfly Biosphere Reserve in
Mexico. Land Degrad. Develop. 20: 22–32 (2009)
From: Iowa
What is OE? OE is a disease that affects monarch butterflies. OE is a parasite. Its scientific name is "Ophryocystis elektroscirrha" so it is called "OE" for short. For more information about OE see the Monarch Health website. |
Q: I 'foster' Monarchs. I harvest eggs, raise the
caterpillars, then release the Monarchs. (One year I released over 400!) What
is the best solution to 'wash' the eggs & milkweed leaves to prevent
OE/parasites. I've heard several different things, from different sources. I
live in a city in Iowa.
A: I actually don’t think that it’s necessary to
wash the eggs and leaves. What is important is to be very careful to keep all
of your rearing equipment as clean (sterile) as possible, and not to handle
eggs or larvae after you’ve handled adults. We use 20% bleach to sterilize
everything. You can read more on the raising monarchs section here.
Q: I've noticed that the Monarchs lay eggs on one
other plant in my yard, other than milkweed. It must be in the milkweed family,
as it has pods in the fall. I brought it to my local garden store, they thought
it was climbing morningstar. Is this an adaptation? A previously undocumented
happening? Or are some of the Monarchs just not too bright? These eggs DO
hatch, and the caterpillars do eat those leaves! Any ideas?(I live in a city in
Iowa)
A: I’ve never heard of climbing morningstar. Could
it be /Cynanchum laeve/? This is in the milkweed family, and fits your
description.
From: Ontario
Q: Just a comment in response to this question and
your answer: Q. Do monarchs live in other parts of the world besides Mexico and
the USA? Don't forget Canada! We have tons of monarchs up here!
A: Yes, you do! Well, maybe not tons, but certainly
lots.
From: Florida
Q: I live in Port St Lucie, FL, have about 45 or
more Milkweed plants in my yard and usually in winter I always have Monarchs.
My plants (and house!) are swarming with cats and eaten up by late March. Not
this year. Has the winter population moved further south? I harvested and
raised 3 cats in Jan when I realized the cold was affecting them and there were
no adults. Their cocoons hatched inside after 25 days-not 10- into healthy
adults. I hated to release them in the weather. Has the weather killed our
Florida Monarchs? Since mid Jan I saw one lone male in mid- Feb.How has the
weather affected them?How and will the population recover?
A: It would be really interesting to report your
findings on the Monarch Larva Monitoring Project website.
Until people report what they’re seeing in Florida, we really won’t know what
the patterns are. But cold weather (below about -5F) does kill monarchs, at any
stage, and definitely slows down their development.
From: Florida
Q: Does the golden yellow New Zealand invasive wasp
kill or lay eggs in emerging caterpillers?
A: Many wasps are predators while they are adults;
I’m not sure just what species you’re referring to here, so I can’t be sure.
Predatory wasps often eat caterpillars. There are also many parasitoid wasps,
which do lay eggs on larvae or pupae, and then the developing wasp larvae
consume the caterpillars from within.
Q: Is the NZ invasive wasp a real problem or just
another natural enemy for the monarch?
A: If it’s invasive, it’s not a natural enemy.
Q: Is there anything that can be done about the NZ
wasp?
A: I don’t know.
From: Texas
Q: Can Monarchs change their migration route or
destination because of the weather?
A: They can change their migration route, but their
destination is fairly constant from year to year.
Q: What makes Monarchs orange and black in color?
A: They have pigments on their scales, similar to
the pigments in your hair and skin.
Q: Why isn't the milkweed plant poisonous to the
Monarch larva and butterfly?
A: They have evolved to be able to withstand these
toxins. Chemicals in their bodies allow them to tolerate toxins that would harm
other species.
From: Arkansas
Q: We were able to experience a migration of
Monarchs 3 years ago. We were building our house when they showed up and flew
over our hill. They were like snowflakes. We haven't seen them since.
Q: How do we find their local migratory path again?
A: The path varies from year to year, so I would
just keep looking. Perhaps you could try reporting what you saw to your local
newspaper, and encouraging other people to report what they see. You could also
log onto the Journey North website to see where people are reporting monarch
roosts during the fall migration.
From: Texas
Q: Did the bad weather in Mexico hurt the Monarch
Migration in Mexico?
A: The Journey North and Monarch Watch websites
have lots of good information on the effects of the floods near the monarch
wintering sites in February, as does our 2010 Monarch Larva Monitoring Project
newsletter.
In short, the heavy rains probably killed many
monarchs. It’s going to be very important to monitor monarch numbers this
summer to see if there are lasting effects.
Q: Our milkweed froze in our school garden here in
Freeport, TX. We are planting more today. Will there be enough milkweed to
support the Spring Monarch Migration?
A: I hope so!
From: Georgia
Q. Do monarchs have a nose and if so can they
distinguish between smells? Ian Brinson and Carey Tyler
A: They can distinguish smells, but not through a
nose. Monarchs have sensory organs all over their bodies, but concentrated on
their antennae and feet, which detect molecules in the air. When you smell
things, that’s what you’re doing too.
Q: Are monarchs affected by earthquakes? Madison
Croft
A: Certainly if the earthquake destroyed their
habitat, they would be affected. We don’t know if they can sense earthquakes
and respond to them.
Q: Do monarchs have leaders and if so, how are they
identified?
A: Probably not.
Q: Do colored pots attract butterflies?
A: I don’t know.
From: Virginia
Q: About a year ago last Oct. I observed a hornet
attacking a monarch repeatedly when the monarch was trying to feed on some
aster blooms. When I knocked the hornet off the monarch (with a long twig) the
hornet went to a second monarch and attacked it until I again knocked it away.
Do hornets normally attack monarchs like this? This happened when there weren't
many other flowers remaining in bloom--but lots of asters in three different
clumps. The hornet was probably one that had survived being burnt out of its
home in a tree that was felled and burned by a neighbor a couple of days
earlier.
A: Hornets definitely prey on monarchs, but I’m
more familiar with them attacking the larvae. There are reports of wasps eating
monarchs during the winter in California, but I haven’t observed this during
the summer breeding season.
From: Michigan
Q: We received monarch larva through the
Butterflies in Space program. They came with their food. We place them in the
same little containers they had on the ISS. However we discovered some things
and wondered what might have happened. Out of six larvae one pupated and stayed
green the entire time. When he emerged he made it halfway out and never came
further. He died that way. The second one pupated and fell to the floor of the
container two days later. He landed in food, stayed green and tried to emerge
with the same results as the first. The third pupated and turned black two days
into the chrysalid. the fourth made the little "j" and then stretched
out and died. The last two died as caterpillars. What happened? Any ideas?
A: This sounds like your larvae were just weak for
some reason. It’s hard to tell why, but the failure to pupate or emerge
completely is fairly common. I would recommend reporting this to Monarch Watch
to see if they’ve had other reports of larvae from this program having similar
problems.
From California
Q: My students were wondering about what endangers
the monarch. We often see monarchs lying on the highways. Are they harmed by
things they are eating and what are their predators?
A. If they are lying on the highways, I would guess that they were killed by cars.
