Are We Loving Monarchs to Death?

By Susan Brackney | June 21, 2016 7:30 am

(Credit: Michael Warwick)

Until recently, monarchs have mostly been at Mother Nature’s mercy—contending with disease, weather fluctuations, and heavy predation in the wild.

Lately, however, the efforts of a well-meaning public to bring monarch eggs and larvae indoors to raise to maturity, or to purchase large numbers of farmed monarchs for release into the wild, may be making life even more difficult for the beleaguered butterfly. Experts suggest such activities expose monarchs to disease, interfere with its genetic diversity, and stymie scientists’ efforts to track its migration patterns. Sadly, this isn’t the first time our good intentions toward monarchs have gone bad.

Monarchs in Decline

“People know monarchs have been in trouble. Their numbers in Mexico have been low for the past several years,” says Sonia Altizer, director of Project Monarch Health and a professor at the Odum School of Ecology at the University of Georgia. Scientists have observed declines by as much as 97 percent of historic highs and 97 percent of long-term population averages.

According to Sarina Jepsen, director of Endangered Species and Aquatic Programs at The Xerces Society for Invertebrate Conservation, “There were highs of almost a billion monarchs—like 800 million monarchs. Currently, this last year, I think we had counted in Mexico either 120 or 150 million.”

To help boost monarch populations, more and more gardeners and armchair naturalists are removing monarch eggs and larvae from the reach of predators, raising them indoors and subsequently releasing the adult butterflies back into the wild. Still others purchase large numbers of captive-bred monarchs from commercial butterfly farms for release into the wild. Sounds helpful, right? Wrong.

“I know people who purchase monarchs and use them in outreach and education, but, if you’re buying them with the goal of, ‘I’m going to release them and supplement the population,’ there are a lot of problems with that,” says Altizer says.


(Credit: Susan Brackney)

Ongoing Debate

These practices troubled a group of leading entomologists and conservation biologists to such a degree that they set aside differences in opinion just long enough to issue a consensus statement against the release of purchased, mass-reared monarchs from butterfly farms. They also urged individuals rearing monarchs on their own to do so only while following safe rearing protocols and participating in citizen science programs such as the Monarch Larva Monitoring Project and Monarch Health.

Reaching that consensus wasn’t easy.

“There were some [conservationists] who thought people shouldn’t be rearing any [monarchs indoors.],” recalls Karen Oberhauser, a professor in the Department of Fisheries, Wildlife, and Conservation Biology at the University of Minnesota and director of the Monarch Larva Monitoring Project. “Well-meaning and smart people are going to disagree on a lot of things, and none of us has a monopoly on the truth.”


(Credit: Noradoa/Shutterstock)

Elizabeth Howard, director of Journey North, an ongoing citizen science study of wildlife migration, notes, “I would say [the statement] could have been even stronger…. It’s such a balancing act, because all of us recognize how important the experience of raising monarchs is from a public education standpoint … Where it gets complicated is when you get into the question of how many. How many is enough? It’s the mass rearing that really raises concern.”

‘Scientific Vandalism’

Most experts agree that mass monarch rearing—particularly via commercial butterfly farms—and mass butterfly releases (say for weddings, funerals, and other events) are nothing but trouble. On the topic of mass releases, famed lepidopterist Robert Michael Pyle writes, “When celebrants are misled into thinking that they are doing something ecologically acceptable, even positive, by tossing monarchs into the void at their events, they are in fact party to scientific vandalism; rather than acting ‘green,’ they are helping to undermine our ability to correctly interpret the response of wild monarchs to all the challenges they face.”

Hospice organizations across the U.S. have also adopted the practice. “The organization buys [farmed butterflies] and then they charge people to release them as part of their fundraiser. That’s why it’s becoming so embedded, because people are doing these annually now … they’re raising a lot of money,” says Howard.

“There is absolutely no educational message. In fact, if anything, there’s a disregard for what happens to the butterfly when everybody goes home,” she adds. For its part, the International Butterfly Breeder’s Association (IBBA) released its own statement in defense of mass butterfly releases.

On average, one dozen monarchs sell for about $100. A charity can then charge members of the public between $30 and $50 per butterfly, pocketing the difference. But the monarchs themselves may be paying a higher price.

Risky Business

Commercial butterfly farms are largely unregulated, and the quality and health of the butterflies they produce can vary widely.

“With some growers,” says Altizer, “every single one of their butterflies is heavily infected, and, with other growers, none are. I don’t want to point a blanket finger at all commercial growers, but, in general, the risk is there. We’ve found that at least half of the commercial growers that we’ve looked at have problems with disease.”


(Credit: smilesbevie/Shutterstock)

Overcrowded conditions and poor hygiene are often to blame for the spread of Ophryocystis elektroscirrha (OE), a harmful protozoan that can cause serious deformities in adult butterflies. Some affected adults may appear healthy but still spread OE to other butterflies and larvae through the release of OE spores. Whether raised in a commercial facility or by well-meaning amateurs, sick, captive-reared butterflies that are released into the wild can contaminate existing, wild monarch populations.

“One of the things that is not mentioned in [our] statement is that butterflies all fly to the same place for the winter. So, if ever you were to think of a bad situation for any sort of communicable disease, you have it right there.” says Howard.

“I think also, in terms of raising a few [monarchs] in your back yard, or many, many, many people raising a few, it’s a drop in the bucket,” she continues. “The growth in the population would only be linear in that way, whereas the risk of disease is exponential. So, in terms of a numbers game, for every monarch you’re releasing, you’re adding one to the pool, but you’re potentially introducing disease that will spread exponentially.”

Migratory Miscues

Butterflies reared indoors don’t always develop the proper physiology to migrate either. They are often slightly smaller than their wild counterparts—and wings that are just a millimeter or two shorter than average can spell disaster for a butterfly on its long flight to Mexico.

Natural environmental cues like decreased day length, more extreme day-night temperatures, and deteriorating milkweed quality cause monarchs to enter a pre-migratory state known as reproductive diapause.

“When they’re exposed to one or more of those combinations of cues, they’re more likely to enter that migratory physiological state where, instead of having developed reproductive organs and being ready to breed, their reproductive organs are actually underdeveloped … and, instead, their bodies are primed to just tank up on fat and nectar,” Altizer explains.

Instead, monarchs raised indoors may be exposed to consistently long periods of artificial lighting, constant temperatures (thanks to air conditioning), and only the choicest milkweed (thanks to the keepers feeding them) while in captivity—thereby removing the environmental cues essential for triggering that pre-migratory state.

What Really Helps

Despite the potential pitfalls, in some instances, researchers believe it is still appropriate for individuals to raise small numbers of monarchs indoors.

“As long as [people are] rearing [monarchs] carefully, it’s not going to hurt those individuals or the population, and, if they’re reporting their data to a citizen science project, it’s going to help us understand monarchs,” says Oberhauser.

Altizer agrees, “In my mind, it’s not cut-and-dried, black-and-white where I would say people should absolutely never rear monarchs … there are some people who go to great lengths to educate themselves about hygienic rearing practices and about monarch disease, and go to great lengths to keep the conditions as natural as possible.”

Not ready to commit to a citizen science project? You can still be part of the solution for monarchs by planting native milkweed as well as nectar-rich plants and donating to organizations dedicated to monarch preservation, such as the Monarch Butterfly Fund and The Xerces Society for Invertebrate Conservation.


CATEGORIZED UNDER: Living World, Top Posts
  • Warren Lauzon

    The road to hell and all that.

  • Maia

    Mostly agree with all these precautions. I have a very small patch of milkweed, have raised a few caterpillars indoors when they are being pestered by parasitic tachnid flies, then I release them. I used to report to a “citizen science” website, but so few now to report…

    But what was not mentioned in this article is the mass killing of milkweeds with Roundup/glyphosate that has been and still is, a huge setback for Monarch numbers and health.

  • Marc de Roche

    Many allegations and strange citations: “Most experts agree that mass monarch rearing and mass butterfly releases are nothing but trouble.” Which expert said it? Really an expert? More than one? Surely not most of them…
    “We’ve found that at least half of the commercial growers that we’ve looked at have problems with disease.” Who we? And how many growers have been looked at? Two? More? I never heard about such a study.
    This fingerpointing doesn’t help.

    Bring back milkweeds and forbid herbicides with glyphosates. Milkweed is what the monarch butterflies rely on. Use of glysophates accidentally have decimated the monarch butterfly population, reduced it over the last two decades by 90 percent. That are the facts.

    Butterfly releases have nothing to do with this decimation.

    • JohnO

      As an old farm boy and present plant scientist, I reject the finding that relatively recent use of glyphosate has anything to do with a decline in milkweed. The many native Asclepias species are perennials. They were eliminated from cropped ground long ago with plows and other cultivation. The weeds found in cropped ground are almost entirely annuals. I doubt the authors of the study blaming glyphosate for milkweed decline were aware of any of this, never having been in a field 50 years ago.

      • Maia

        Roundup has been here for sure since the 80s, that’s long enough ago, about 35 years. Also, it’s not just spraying, it’s clearing of ground and roadsides, habitat losses due to housing projects, hotels, highways and ever more cement, ever fewer patches of open ground. More to it as well, glyphosate is part of a larger pattern in eliminating milkweeds (there are about a hundred species), and replacing them with plants Monarchs cannot survive on. (Bees like milkweeds too, btw.)

        • JohnO

          Glyphosate wasn’t around in the ’50s and ’60s, when milkweed was already long gone from crop fields. If you were in any farm fields at that time, as I was (hand weeding in pre-herbicide days), you would have seen no milkweeds. As to the other stresses on milkweeds you mention, true as far as they go but not relevant to my comment.
          Further, don’t lecture me about milkweeds. My urban landscaping is overrun with them (by design) as well as other native species. In the last couple of years I’ve greatly increased the amount of native blue “sage” (Salvia species) on my property. I’ve noticed the late-blooming sage is an important flower for monarchs headed south in the fall.

          • Maia

            We have a difference of experience…and readings. But I see no lectures anywhere… I’ve been a gardener since the sixties, and a roamer of fields, and live near Monarch roosting areas, so I am fiarly familiar with their patterns and abundance. Blue sage is great for nectaring, I was talking about eggs and caterpillars, which cannot do with milkweed, as I’m sure you know. When medians and roadsides are “weeded” it is often done with spraying herbicides…that’s an ongoing process to this very day…

          • JohnO

            They don’t use glyphosate on roadsides. It would kill everything. The “researchers’ erroneous conclusions about glyphosate in agriculture are what I originally pointed out. The “researchers” haven’t been in any fields and neither have you. Or if you were, you either weren’t paying attention, or didn’t know that you were seeing. If you were, you were also trespassing.

          • Maia

            You seem to be making pronouncements about things you cannot know: namely, my own experience. That tends to end conversations.

          • JohnO

            And talking to you is like talking to a 3-year-old. You blithered about everything except the single simple valid point I raised in my original comment.

          • Lee Finney

            in Jackson County the road dept routinely sprays glyphosate along roadways. A private homeowner can
            sign an agreement to keep their properties along roadways clear of weeds manually. and you are right…it does kill everything… including pollinators.

  • Dale McClung

    The author mentions: “There is absolutely no educational message. In fact, if anything,
    there’s a disregard for what happens to the butterfly when everybody
    goes home,” she adds. For its part, the International Butterfly
    Breeder’s Association (IBBA) released its own statement in defense of mass butterfly releases.

    My name is Dale McClung and I am listed as the media contact on the IBBA website, but was not contacted. There is much misinformation to refute in this article based upon a press release, too much for a simple comment, so I invite someone on the Discover staff to write me at:

    • SeEtta

      It is most unfortunate that members of IBBA are more interested in the profits they derive from these harmful mass butterfly releases than in the survival of Monarchs.

  • Marv Hanner

    The discussion is about “loving monarchs to death”. I grew monarchs in old glass jars when I was a boy 65 years ago in Iowa under less than ideal conditions. It was a learning experience. While growing monarchs indoors may not be the best solution, it does provide an increase to a population which is sorely depressed.
    The biggest problem seems to me to be loss of habitat. There were many more monarchs then than now. Twenty years ago I moved to southern Wisconsin after spending twenty years in Arizona and New Mexico where there are very few of the broad leafed milkweeds. At that time there was a moderate population of butterflies here. Now, there are almost none. I have provided room in my lawn and garden for milkweeds and have seen only two or three butterflies each of the last few summers. The state highway department mows down the vegetation on the roadsides all the way to the farmers fence lines right at the time when the milkweeds are three feet or more high just at the time larvae would be about one half grown. I am speaking of thousands of plants destroyed just in one county alone. If anyone can point me to an organization that promotes butterfly survival and habitat preservation I would like to investigate possible membership.

    • Maia

      Agree completely. The only org I can think of is Journey North which is a citizen science site that follows not only Monarchs (and asks for reports of what we see, etc) but also grey whales, hummingbirds, songbirds, and more. You can check it out. The entire migratory route is followed and we get sent bulletins on what’s happening. However there ARE monarchs that do not migrate, and they are not covered. Go online and take a look..good luck.


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