Raise Monarchs? Learn about OE and How You Can Prevent Infections

In the last ten years word has gotten out about the decline in monarch butterfly populations and more and more people are wanting to help these beautiful butterflies. What’s not to love about monarchs? They are beautiful insects who bring joy to a lot of people, both here, in Canada, and in Mexico where they overwinter. It’s great that people are getting on board to make changes. It’s great that people want to help them! 

But unfortunately, there is some bad news about monarchs and some things well-meaning people are doing that are actually contributing to the problem. Many of these people are completely unaware of this fact. I’m here to ask you to help me spread the word because the more people who know, the better off the monarchs will be. 

It’s complicated and I am not wanting to write a lengthy piece about the parasite called OE. There are many, many pages on line (OE spores explained, and a piece about the danger of growing tropical milkweed. ) about this and you can look there for more information.

The bottom line is this: If you want to help monarchs, the best thing you can do is to plant NATIVE milkweed in your yard and educate others. Trying to raise monarchs to “save them” is like trying to save chickens by bringing a few into your yard. 

Notice I said native milkweed. This doesn’t include tropical milkweed, and here’s why: Tropical milkweed is contributing to the problem because unlike our native species of milkweeds, tropical milkweed doesn’t die back in late August, early September. Instead, it has lush green leaves will into October or even later. In Texas and Florida and along the Gulf Coast, tropical milkweed doesn’t die back at all, and lasts throughout the winter most of the time. This is a problem because migrating monarchs are enticed by the lush, tropical milkweed leaves and will become reproductive, even though historically they are on a mission to get to Mexico, not reproduce. When they switch tracks and lay eggs, this means young monarch caterpillars will be munching on the milkweed well into the fall. There is no way those monarchs will make the journey to Mexico so late in the season.

At first glance this may not seem like a problem, after all, isn’t having MORE monarchs a good thing? Well actually no. There is a parasite called Ophryocystis elektroscirrha, or thankfully! OE for short that is wrecking havoc on the monarch population. OE spores cluster on the outside of the adult monarch’s body, sometimes numbering in the thousands, or even millions. Adult monarchs infected with these OE spores may look perfectly normal. Just by looking at a monarch there is no way to determine if it is infected by OE. However, individuals infected with OE do not have reproductive success, do not survive long and have reduced flight ability. 

Because tropical milkweed lasts longer, there is a higher chance for it to be infected with the spores of OE. Think of OE like glitter–it is everywhere once a plant or butterfly is infected and just about impossible to get rid of. OE spores are microscopic, often present on the milkweed in giant numbers, or on the butterflies. Eggs that hatch into caterpillars on tropical milkweed are easily infected with OE spores. Studies show that those adults infected will not make it to Mexico. 

People who raise monarchs need to be aware of OE. Suppose someone is raising monarchs in a big netted area, with the caterpillars and the butterflies all enclosed together. When the adults eclose from their chrysalis at the top of the container, as soon as they open their wings they can potentially be spreading hundreds, thousands, or even millions of OE spores onto everything down below. So now all of those eggs, caterpillars and milkweed leaves could have OE spores! It’s easy to see how quickly the entire population that you are raising can become infected! This is definitely not what you set out to do, as you are now doing more harm than good.

Thankfully, there ARE ways to help the monarchs– those are:

1. Don’t buy monarchs (or other butterflies) from commercial breeding operations and don’t support people who do. These are popular at weddings, graduations, funerals, etc, but tests on these butterflies often shows they have OE spores. Don’t support these operations!!  It’s a lot to take in and too much for me to cover here so — Here’s why Xerces doesn’t support this practice.

2. Stop planting tropical milkweed! (Asclepias curassavica and Gomphocarpus physocarpus.)  Instead, choose native species for your area. Here’s a place to start if you don’t know where to find native milkweed. Also, if you live in western NC, here are some upcoming plant sales where my friend Kim Bailey will be selling native milkweed.

3. Join the movement to educate others about the dangers monarchs face, including infection from OE spores.

4. If you feel you must raise monarchs, please do so responsibly. The eggs can–and should– be bleached to kill OE.  Here are directions for doing this. The containers you use must be regularly bleached and cleaned. The caterpillars must be never be beneath, or with, emerging adults. Here’s what Monarch parasites. org has to say “The parasite spores are very small and easy to accidentally spread around. It’s important to wear gloves to minimize the spread of spores from one sample to another. Always change gloves between handling different butterflies. One monarch may be infected, while another may not. It’s important to try and keep a clean work area when handling and sampling the butterflies for parasites. Bleaching any containers, tools, and work surfaces the butterflies touched prevents cross-contamination of different samples and helps avoid touching a non-infected sample with infected spores from another. We suggest a 20% bleach solution be used between sampling individuals and also between different sampling periods.”

If you don’t feel like you have time, or don’t want to be bothered with this, the honest truth is that you shouldn’t be raising monarchs. Just leave them in the wild. I know this isn’t what many people want to hear but it is the truth and there is plenty of science behind it; this is not my opinion.

Here’s what Xerces has to say about captive rearing of monarch butterflies: “Instead of rearing—which is risky and unproven in helping monarchs—we should focus on more effective ways to conserve these glorious wild animals. Our tactics should address the reasons the species is in trouble to begin with. We can do this through taking action to protect natural habitat; to plant native milkweed and flowers; avoid pesticides; support wildlife-friendly, local, and organic agriculture; contribute to research efforts via community science; and organize ourselves to push for policy changes. These are more effective ways to expend our energies in monarch conservation than trying to rear the population back to health—which we do not know is possible and may spell trouble for an already at-risk species. For more information about ways to help monarchs, check out resources on the websites of the Xerces Society and the Monarch Joint Venture.”

Let’s say you just have two or three monarchs that you’re raising to share with your kids, or grandkids, or just to see for yourself. If you want to check your adult monarchs to see if they are infected with OE, you can do a simple test. Using a piece of scotch tape, you gently remove some of the scales on the buttefly’s abdomen. Put this on a white piece of paper. Then look at in under a microscope. Don’t have a microscope? You can buy this mini hand-held microscope on Amazon for under $15. The spores show up if the butterfly has OE. These look like tiny dots all over the image. Check out these photos –and do ignore the last sentence on the slides about the link in my bio–it’s meant for my instagram account. 

If you find a butterfly you’ve raised has OE, you should put it in the freezer and not release it for the good of the monarch population. Releasing an infected butterfly is irresponsible. 

 

 

Here’s a great post about The Five Stages of a Monarch Butterfly Advocate. (In summary those are: 1. Helping 2. Raising monarchs 3. Butterfly garden 4. Science denial 5. A lightbulb goes off) It’s a great post and really talks about why the best thing you can do is not raising monarchs at all, but educating others about monarchs. (Written by Andy Davis who is a research scientist at the Odum School of Ecology in the University of Georgia – link to the Davis lab website here. Andy has been studying monarchs, especially their amazing migration since 1997, and is the editor-in-chief of a scientific journal devoted specifically to animal migration. Andy is the author or coauthor of 35+ scientific studies on monarch biology. Andy is also married to a much more famous monarch scientist – Sonia Altizer)

We are all on the same page in that we want to help the monarchs and preserve their fascinating and inspiring migration. We have come a long way in the years since the alarm about the monarchs decline was sounded. Now, because we have all of this information, let’s get on the same page about the best way to protect the monarchs moving forward. Please help me pass this along to everyone you know!