How Exactly is Monsanto’s Roundup Ravaging the Monarch Butterfly Population?

Monarch Butterfiles Female left Male right Milkweed ©Kim Smith 2012The above photo of a male (right) and female (left) Monarch Butterflies on Marsh Milkweed is part of the GMG/Cape Ann Giclee show opening tonight.

I am often asked the following question at my butterfly and pollinator garden design lectures. How exactly are Monsanto’s products ravaging the Monarch Butterfly population?

First, it is important to understand that all butterfly caterpillars rely on plant foods specific to each species of butterfly. For example, Monarch caterpillars only eat members of the milkweed family, Black Swallowtail caterpillars eat plants in the carrot family, and Heliconian butterflies eat plants in the passionflower family. Some caterpillars, like the larvae of the Eastern Tiger Swallowtail eat plants from a wide range of plant families. That being said, it is worth repeating that Monarch caterpillars only survive on members of the milkweed family.

Imagine a farm with row upon row of corn. Growing amongst and around the edges of the cornfields are wildflowers of all sorts, including milkweed. The wildflowers draw to the fields myriad pollinators such as bees, butterflies, and birds.

Monsanto has genetically modified the seed of corn and soybeans so that it will withstand extremely heavy doses of its herbicide, called Roundup. Monsanto’s corn and soybean seed is actually called Roundup Ready. Roundup Ready plants can withstand massive doses of the herbicide Roundup, but the milkweed and other wildflowers growing in the corn and soybean fields cannot.

Each year massive amounts of Roundup are sprayed on the corn and soybean fields, killing everything in sight, except the Roundup Ready corn and soybean. Additionally, Monsanto’s Roundup contains the active ingredient glyphosate, which has been tied to more health and environmental problems than you can possibly imagine.

Now imagine you are a Monarch Butterfly, having flown hundreds of miles northward towards breeding grounds of milkweed. But there is no milkweed to deposit your eggs. The circle in the chain of life is broken.

Since the use of genetically modified Roundup Ready began, milkweed has disappeared from over 100 million acres of row crops, or a roughly 58 percent decrease. Milkweed is not only the Monarch caterpillar host (or food) plant, the nectar-rich florets provide nourishment for hundreds of species of bees and other Lepidoptera.

The Monarch Butterfly migration is one of the great migrations of the world. Climate change and the loss of habitat are also factors in the decrease of butterflies. The Mexican government and the people of Mexico have enacted policies to help protect from logging the remaining oyamel fur trees in the Monarchs winter habitat.

There are several steps that we in the United States can undertake. 1) Avoid as much as possible genetically modified food, especially corn and soybean products. 2) If you own shares of Monsanto stock, get rid of it (Monsanto also developed Agent Orange). Thirdly, we need to start a national movement to cultivate milkweed and to create awareness about the important role wildflowers play in our ecosystem.

Calling Everyone: Plant Milkweed! No matter how small or large your garden, give a spot over to milkweed and watch your garden come to life!

46 thoughts on “How Exactly is Monsanto’s Roundup Ravaging the Monarch Butterfly Population?

    1. love milkweed and queen anne’s lace in my husband has been fighting me for 49 years. i am still winning.


  1. There is a debate about why monarch butterflies have been declining over decades. It is very possible that the overuse of weed killers is the culprit. It would be ironic if GMO was blamed when actually GMO could save the Monarch. It has been shown in many studies that GMO crops use much less herbicide and insecticides than non GMO crops.

    But after decades of decline the new boogeyman is GMO crops. They are blamed for everything. Bee decline (although bees have been declining for decades) bad posture (oh wait, GMo hasn’t been blamed for that, yet.)


    1. More studies and articles for you Paul

      From the Lincoln P. Brower study:
      Loss of breeding habitat in the United States
      Seiber et al. (1986) and Malcolm et al. (1993) determined through thin layer chromatography that 85 and 92%, respectively, of 394 and 382 overwintering monarch butterflies in Mexico had fed as larvae on the Common Milkweed, Asclepias syriaca. The importance of A. syriaca reflects history of the landscape. A rich pre-colonial milkweed flora was widely distributed, with 29 species of Asclepias, most of them grassland species (Woodson, 1954; Hartman, 1986) native to the late summer breeding range of the monarch (Malcolm et al., 1989, 1993; Wassenaar & Hobson, 1998). However, ploughing of the prairies and deforestation led to an increase in the distribution and abundance of A. syriaca (Brower, 1995), which Woodson referred to as the pre-eminent weedy North American milkweed. Now with an increasingly patchy distribution, this species is the dominant milkweed in the monarch’s eastern North American breeding range.

      A survey in 1999 of habitats containing this milkweed species showed that the number of monarchs produced per ha in maize (corn) and soya (soybean) fields was as high or higher than that of other habitats (Oberhauser et al., 2001). Genetically modified glyphosate resistant (GR) soya and maize (e.g. Monsanto’s Roundup Ready crops) were rapidly adopted by growers after 1999, resulting in a significant reduction of A. syriaca and the loss of monarch breeding habitats in these croplands. Much of the combined acreage of soya and maize (60–70 million ha per year) is used in rotation, and this rotation in combination with the high adoption rate of GR soya (>70% by 2002, presently 92%) and maize (presently 23%) (U.S.D.A., 2010a) has all but eliminated A. syriaca from 40 million ha of these croplands (Taylor, 2008). Both Hartzler (2010) and J.M. Pleasants (in prep.) have documented the drastic reduction of A. syriaca growing in glyphosate-treated fields in Iowa; Hartzler recorded a 90% loss from 1999 to 2009, and Pleasants measured a 79% loss from 2000 to 2009. We conclude that, because of the extensive use of glyphosate herbicide on crops that are genetically modified to resist the herbicide, milkweeds will disappear almost completely from croplands. Furthermore, Zalucki and Lammers (2010) have estimated with models that the large-scale elimination of milkweeds in agricultural and surrounding landscapes has the effect of increasing the search time for host plants by monarch females with the result that realised fecundity is reduced.

      In addition, milkweed habitat has been lost due to increasing demand for biofuels. Conservation Reserve Program (CRP) area has been decreased by 2.3 million ha since 2006 (U.S.D.A., 2010b) and as yet undetermined but large areas of grassland and rangeland have been converted to biofuel crops, especially maize (Stubbs, 2007). Over this same interval, maize and soya planting increased by more than 5 million ha (U.S.D.A., 2010a, and previous year reports from the USDA National Agricultural Statistics Service). Coupled with the habitat lost to development, which has been calculated as nearly 1 million ha each year from 1992 to 2007 (U.S.D.A., 2003, 2009), these losses add to at least 56 million ha (roughly 220 000 square miles). This is more than one-fifth of the estimated eastern North American summer breeding range of the monarch (Brower, 1999). The cost to the monarch population of habitat loss due to GR crops, increased planting of maize and soya, in addition to development is surely significant.


  2. The point of the answer to the question “How exactly are Monsanto’s products ravaging the Monarch Butterfly population? is to answer in a way that is hopefully easy for everyone to grasp.

    I don’t really care what GMOs have been blamed for in the past. I am talking here about a direct correlation between the extensive use of of glyphosate herbicide on crops that are genetically modified to resist the herbicide. It borders on the ridiculous to write that GMOs may be the very thing that saves the Monarch. When the GMOs were first developed, they were advertised by Monsanto as needing less herbicide, but in actuality, more than ever is in use.

    “Both Hartzler (2010) and J.M. Pleasants (in prep.) have documented the drastic reduction of A. syriaca growing in glyphosate-treated fields in Iowa; Hartzler recorded a 90% loss from 1999 to 2009, and Pleasants measured a 79% loss from 2000 to 2009. We conclude that, because of the extensive use of glyphosate herbicide on crops that are genetically modified to resist the herbicide, milkweeds will disappear almost completely from croplands.”


  3. A comment about tone on the blog…. Mr. Morrison says: “But after decades of decline the new boogeyman is GMO crops. They are blamed for everything. Bee decline (although bees have been declining for decades) bad posture (oh wait, GMo hasn’t been blamed for that, yet.)” While his response is clever, it is not very informative and is in fact rather condescending. Ms. Smith is attempting to engage the community in a serious scientific dialogue, and it would seem to me that Mr. Morrison ought to be a little more respectful and offer something more substantial to the conversation.


    1. Bee colony collapse has been suspected to be related to pesticides and herbicides for some time, and now the Monarchs. GMO’s mean more herbicides can be used. Thank you Kim.


        1. Monsantos’ Roundup means that more Roundup can be applied. I gotta keep on quibbling about saying it is GMO that is doing it or GMO means more herbicides being used because it is not true.


        2. Yes it is true Paul. Again, please lets keep the conversation about what we can do to help the butterflies.

          Rodale Report: Genetically Engineered Food Gets Doused with Extra Chemicals

          …”Researchers at The Organic Center used U.S. Department of Agriculture surveys on herbicide, insecticide, and fungicide use from the last 13 years (the period since genetically engineered crops were first planted), as well as pesticide information collected from Monsanto. Herbicide-tolerant crops accounted for 72 percent of all the “trait acres” (acres with a crop containing one GE trait) planted with genetically engineered seeds between 1996 and 2008, they found. While the Bt crops led to a consistent year-over-year reduction in insecticide use, herbicide-tolerant cotton boosted herbicide use by significant amounts. In 2007, cotton farmers were using 200 percent more Roundup on their crops than they were in 1996, at an average annual increase of 18 percent, while soybean farmers were using 98 percent more (a 10 percent annual increase) and corn farmers 39 percent more (a 5 percent annual increase; herbicide-tolerant corn was adopted more slowly than other GE crops). At the same time, researchers noted, farmers who were growing conventional (not genetically engineered) soybeans and corn saw downward trends in the amounts of herbicides needed, using 26 percent fewer pounds of pesticides than farmers of genetically engineered crops.”


  4. Roger is right, I was too flippant in my response to Kim. Since I know Kim I thought I could cut to the chase but doesn’t mean I can be an ass. I apologize.

    By cutting to the chase I have to leave out a lot of stuff. I have been genetically engineering organisms in basic research for the past 33 years. That doesn’t mean I am an expert worth listening to because unless I can explain myself I am not getting anywhere.

    But GMO is near and dear to my heart. I see people throwing GMO under the bus, and it concerns me. We have golden rice, a “GMO” which could save over half a million kids in the third world from blindness and death each and every year but Greenpeace has successfully halted golden rice from being used. There is no scientifically valid reason. So Greenpeace has killed a million children in the past two years while holding golden rice up. Thanks Greenpeace. Their response? Those kids should eat organic green leafy vegetables and they would not die. Thanks Greenpeace.

    The reality of Monarch butterflies requiring milkweed has always been there. Before GMO the only way for farmers to compete with the weed was to till the soil aggressively and use broad spectrum herbicide. One sends the midwestern topsoil down the Mississippi river and the second is highly toxic. I have not seen data showing more herbicides being used on Roundup Ready crops, I have seen data that shows less.

    “Additionally, Monsanto’s Roundup contains the active ingredient glyphosate, which has been tied to more health and environmental problems than you can possibly imagine.”

    Herbicides are nasty. But glyphosphate herbicides are a lot less nasty than what they used before.

    I have one suggestion which may have more impact on Monarch butterflies than any of this. It is the fact we are now growing enormous amounts of corn (thus wiping out milkweed in the process) on new lands. Why are we doing this? Because for some crazy reason people think it is more environmentally correct to spike all gasoline with 15 % ethanol. The 15% ethanol rules is killing the Monarch more than anything. It’s also ruining your outboard motor on your boat. And now we are going to raise the percent so we can kill more boat engines and Monarch butterflies? Something is wrong here and it is not GMO crops.


    1. The studies that I cited were written by two of the most respected scientists in their field, Doctor Lincoln P. Bower, with well over fifty years of field work and hands on research of the migration, conservation, and biology of the Monarch Butterfly, and Chip Taylor, Professor Department of Ecology and Evolutionary Biology, University of Kansas, and founder of Monarch Watch (1992).

      Let’s turn this conversation back to what can be done to help the butterflies survive the immediate crisis of the loss of nearly half their breeding grounds since 1999. We need a nationwide call to plant milkweed. If we don’t replenish the milkweed, we will lose the Monarchs.


  5. You’re missing my point because it might seem small but from someone who works with GMO it is a huge point. You should be saying, “Monsanto and Roundup” instead of “GMO”. There is a big difference. Don’t throw the baby out with the bathwater. There is nothing wrong inherently with genetically modified organisms. They are only a fine tuning of what man has done to plants for thousands of years. It is another tool for a plant breeder to use.


  6. I think you are missing the point Paul. Please read the original post-that is exactly what I wrote.

    Monsanto’s Roundup Ready GMO seeds are designed by Monsanto to be used in conjunction with Monsanto’s herbicide Roundup. Lets please just agree to disagree and move the conversation to how we can help all pollinators, bees and butterflies. See my post today at 2:00.


    1. Sorry Kim but Paul is right. Yes, is wrong to say GMOs in general. Yes is right to speak now in this post about the Roundup and Monsanto, and the possible effect on the Monarchs butterfly. (Still, are there studies about it? there was the big one in 1999-2001 about the Bt Maize, and turned out to be actually negligible). Kim is right, the article title states “Monsanto and Roundup”, and we should speak focusing on this, and Paul should also stick to it. As also all the others in their comments, mentioning GMOs in general. Wrong. Very wrong. And KIm you are picky with Paul, but you blink to all the others if they mention their concern about the GMOs in general. There is a lot of prejudice and ignorance in the GMO debate and I hope you are aware of it.


  7. just in case my reply gets lost in the exchange – who can I talk to to find out what’s needed to plant milkweed?


  8. Kim: Thanks very much for this important information. I found it very useful, as I did not know most of these details.

    I am very frightened by the Monsanto decision, and their use of these pesticides – for many, many reasons.

    I also love Monarch butterflies and would be happy to do anything to help them survive. Thanks for the solid info and the milkweed tip.


  9. Thank you Kim for posting the need to be aware of the butterfly’s decline. Bees are an issue as well as people. The GMO products not only deal with weeds but with bugs also. The product that eliminates bugs by causing their digestive systems to break down and causing them to die works almost as well on other creatures ( humans and livestock). It’s called leaky gut and more and more people have started to have this problem.
    Round-up is a whole other nightmare. That has been linked to Non Hodgkin’s Lymphoma. Something I know too much about. The UK has banned it long ago. Monsanto is a giant with no soul.

    Liked by 1 person

  10. This information is so important. I have great fears about how pesticides and GMO products will harm future generations, let alone ours. Some studies show a link between pesticides and Parkinson’s Disease. (I don’t know specifically which pesticides)

    * Thanks to Kim for sharing this important information. **** Can we purchase Milkweed in plant nurseries locally?


    1. Thank you Terry for your always thoughtful comments. Common Milkweed is not easy to find in nurseries. You may have more success with Marsh Milkweed. I would try New England Wild Flower Society because some years they have small quantities of Marsh Milkweed available. If you can wait until the fall, you can collect the seedpods of Common Milkweed.


  11. Monsanto has the money to buy politicians and until it is stopped it is not only butterflies that are threatened. the health concerns will spread through the food chain right to and including the top of it. This has to be stopped.


  12. This is a very good discussion, Kim, and one which perhaps we could and should have had a number of years ago, prior to approval of some GMOs. Paul and I disagree on the adequacy of testing which has been done on BT modified corn and soy. This is a modification in which a gene from a bacteria is inserted into the DNA of the seed to create a built-in defense against insects. This is the type which has raised concern about food safety, and isn’t really germane to this discussion.

    The Round-Up ready modification is done with another gene to make the plants resistant to Round-Up, which kills broad leaf plants. I was unaware of the collateral damage you’ve brought up, Kim, but it makes perfect sense that with Round-Up resistant crops, farmers would very likely use more of the insecticide as they wouldn’t need to be so careful with it. Perhaps they were even able to change from some other insecticide and buy Round-Up instead. It’s a great marketing scheme which is very good for the manufacturer, but apparently not so good for the butterfly populations.

    I do appreciate Paul’s concern about GMOs getting a black eye from side effects of hasty commercialization. Any new technology can be safely or unsafely applied, and condemnation of all genetic modification shouldn’t be the intention of those of us with concerns about food and environmental safety. But it took our environment a very long time to recover from DDT, and we very definitely do not need another one.


  13. The gmo/roundup regimen is a replacement for the practice of cultivation. Less labor cost per bushel of grain. This is the lazy way out for farmers, as long as they ignore the externalized costs to nature in doing it that way. From what I see, most farmers are making chemical cultivation their method of choice. By doing so they are harming nature- nothing to fool around with.


  14. Great discussion. Have a small farm in southeast NH. 10 acres of pasture with lots of milkweed, no herbicides or pesticides. Abundant Monarchs til last year when marked decrease. This year have not seen a single Monarch! Frightening. Monsanto could care less. Boycott Monsanto related products and you would not buy 3/4 of the products in most grocery stores. Probably not a bad idea. Bob B


    1. Thank you Bob for sharing the Monarch update on your NH pasture, which sounds absolutely beautiful. Yes, I agree, very frightening, and beyond tragic. Hopefully,not permanent.


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