Dear Monarch friends,
Well, it continues to be an interesting summer weather and climate wise. How are your plants holding out? What about the caterpillar population?
Despite the seemingly incessant rain, heat and humidity, Monarch caterpillars in my garden did well, and managed to eat their way through my eight plants. I even have a few smaller instar caterpillars feeding on the spent plants, now mostly stalks, a handful of half eaten leaves, and now seed pods beginning to open.
I monitored three chrysalides complete their metamorphosis to adult butterflies, and am holding my breath for the remaining three I found to make it through. These have been in the usual places – on chairs, hanging from tables, on the siding of the house, hanging from the grill. I know there must be more somewhere…
Attached is a photo from last week. Send your photos and your stories!
Dear Monarch friends,
It’s been an odd summer here weather-wise, and the garden is responding in unpredictable ways. The swamp milkweed bloomed, is going to seed, leaves are drooping, and some of the plants are infested with a variety of insects that feed on milkweed, including aphids, beetles, bugs, and tussock moths. The plants are looking bedraggled and spent, not surprising considering the unusual August heat. I discovered that one of my plants in a raised bed just got too big for its britches. It’s root bound and stressed, so I know I will need to dig it up this fall and transplant it to where it can have more room.
Nevertheless, I have seen more monarchs this year than last year – adults nectaring, eggs, and all stages of instars. This is good news. They are feasting on the leaves, flowers, and now the seeds, and even some of the less appetizing plants are being devoured. I have seen quite a few mature to the fifth stage instar, but have only found one ready to metamorphosize thus far. (It’s forming the J shape, hanging from the arm of one of my Adirondack chairs.) I am hoping some more made it, and are just harder to find. From my observations, I am currently watching the second generation develop in my garden, and if any of them make it to adulthood, they will join the super migrators heading to Mexico before too long.
The link below is summary data of information I have been collecting on a weekly basis for MLMP – the Monarch Larva Monitoring Project – a community science project. People like us all over the country are submitting data to this portal. The organization will use the data to track nationwide monarch density and summary population trends. It involves a commitment of 30 minutes – 1 hour each week, depending upon how many plants you are monitoring. You should consider signing up next spring. It’s fun and will help fine-tune your observational skills.
What are you observing in your garden? Send us some photos!
Dear Monarch friends,
A small and enthusiastic group met in my garden on July 19. Together, we were able to identify a healthy number of Monarch eggs and instars on my Swamp Milkweed plants. Participants left feeling more confident knowing what to look for on their own plants.
The group had several questions regarding life cycles and migration. Here’s what I discovered:
- Egg laying: Females can lay between 300-500 eggs over a period of 2-5 weeks. When laying eggs, the female secretes a small amount of glue to attach the egg directly to the plant. Eggs generally hatch about 4 days after being laid.
- Super-migrators: The ability to migrate, and what differentiates the super-migrators from those who don’t, might hinge on a single gene. Check out this article in the Washington Post.
One of our participants asked if solar activity affects migration. I am still looking for an answer to this question, but did find this interesting article about how climate change affects migration, in Scientific American.
Please continue to keep us posted as to what you’re observing and learning, and keep those questions coming!
Hello Monarch Friends,
With days on end of rain, I have wondered how butterflies fare in adverse weather conditions. I do notice that my flowers are swarming with butterflies and other pollen-loving insects whenever the sun shines, but those moments have been rare.
Below is a link to a brief article from Scientific American about this very issue. Butterflies in the Rain
Tomorrow is our first scheduled Monarch workshop at my house. Our first attempt was cancelled due to rain. Here’s hoping for a break in the weather tomorrow afternoon!
Dear Monarch friends,
Now that the Monarch(s) officially arrived in my garden, I would like to invite you to participate in informal monitoring with me. I will offer one workshop/week and, so that we can gather together comfortably outside, I will limit participation to 8 people at each workshop. I will have magnifying glasses for you to use while you’re here, but please bring your own writing and recording materials.
If you are interested, please reply to me with the date you prefer. I will close registration when I reach 8 people per date, and will follow up with confirmation and directions. I recommend carpooling if someone close by will be attending. If it’s torrentially raining, I will offer a make-up date.
If you are closed out of the first round, please don’t despair. I hope to continue throughout the breeding/egg laying/caterpillar season – as long as the Monarch oblige.
- Tuesday, July 13 9:00-10:00 AM
- Monday, July 19 3:00-4:00 PM
Dear Monarch Friends,
Just after I sent you this afternoon’s message, I went outside and noticed little dots on the flower buds of one of the swamp milkweed plants. That lone female Monarch got right to work. They are Monarch eggs! Notice the shape.
I also attached a photo differentiating males from females for your reference.
Hello Monarch Friends!
Here it is, July 7, and just as I was ready to give up hope, a beautiful female Monarch showed up, sampling nectar from a variety of flowers, perhaps checking out the egg laying potential. I checked my postings to you from 2020, and I saw the first Monarch in my garden on July 7. Amazing!
I have heard from several of you that you have seen a Monarch or two. I think we’re on our way. See if you can identify the females (they don’t have the distinctive two black spots on their wings) and then start looking for eggs on the undersides of milkweed leaves and sometimes on flowers. You can see what an egg looks like in the attached photo. They’re tiny, cone-like and yellowish white – not the white dots which are extrusion from the milkweed plant. You might even get to see the female actually lay her eggs.
Let us know what’s happening in your gardens!
Some trials and tribulations
by John Anderson – A Letter from Grandpa Nature
Monarch butterflies are distasteful to birds. They contain alkaloids called cardiac glycosides which make any bird consuming one retch, vomit, drool copiously and, in general, act very, very sick. The butterfly gets its chemical defenses while in the larval stage. As a caterpillar it eats milkweeds containing alkaloids and accumulates them in its body. When metamorphosis occurs the distasteful alkaloids end up in the butterfly. Therefore both monarch caterpillars and monarch butterflies are distasteful to birds. Any bird that eats one will get so sick that it will very likely never eat another.
Since we know about the monarch’s toxic defense it’s easy to imagine that they live rather carefree lives unbothered by predators. But that isn’t so. The alkaloids that make them distasteful to birds provide little or no protection against insect and arachnid predators and there are a surprising number of both. Mostly they target smaller, early instar monarch caterpillars.
I have seen pictures of both Crab Spiders and Jumping Spiders eating monarch caterpillars. Crab spiders are ambush hunters that wait for prey to blunder into their grasp. Jumping spiders are active hunters, leaping on prey from a distance. Like all spiders these species liquefy and ‘drink’ the internal parts of their victims.
There are also several of the true bugs that will feed on monarch caterpillars including Spined Soldier Bugs, Wheel Bugs, Ambush Bugs and Assassin Bugs. All are voracious predators that stab prey with their piercing mouthparts and drink their liquefied innards. I have seen spined soldier bugs feasting on caterpillars but all of these bugs are generalists. They will eat any caterpillar, not just those of the monarch.
Some wasp species are detrimental to monarch caterpillars. Paper wasps are hunters that kill and chew up Paper Wasp insects including monarch caterpillars to feed to their own wasp larvae. Ichneumon wasps are internal parasites. The female wasp injects her eggs into the Ichneumon wasp living caterpillar. The wasp grubs that hatch from those eggs eat their host from the inside, not killing it until they are finally old enough to pupate.
In the southern states that the monarchs have to colonize annually as populations move north, Fire Ants are a scourge, eating any and all insect life. Areas that have fire ants have almost no insects including monarchs.
Other monarch predators that were once native to Europe were intentionally introduced on this continent as biological controls for various destructive insect species. A beetle known as the Forest Caterpillar Hunter was released to control Gypsy Moth and Browntail Moth caterpillars. It is established in New England, south to Virginia and west to Pennsylvania. Another called the Golden Worm and Slug Hunter was also introduced to control gypsy moth caterpillars. It proved to be a generalist willing to feed on any caterpillar as well as on earthworms. It is mostly found in New England. Both have negatively impacted monarch populations.
Worse than either beetle is a fly which was also introduced to control gypsy moth caterpillars. This fly is known only by its scientific name, Compsilura concinnata. It is a most unremarkable creature, slightly smaller than a house fly and is an internal parasitoid on caterpillars. Unfortunately this fly produces four broods a year only one of which is synchronous with the emergence of gypsy moth caterpillars. The remaining three broods have to find other caterpillar hosts to feed on including monarchs.
All of these introductions occurred many years ago when the potential unintended impacts on other species including monarchs were not as well understood. But now the beetles and the fly are here to stay. Whatever impacts they may have are now integral parts of the world that we and the monarch caterpillars inhabit.
Monarch caterpillars are also susceptible to fungal attack, hosts to internal parasites and to non-lethal protozoan spores that may ultimately decrease their survival rates. But, the most lethal predator of monarch caterpillars is, oddly enough, milkweed. Milkweeds do not want herbivores such as monarch caterpillars eating their leaves. As a deterrent they produce the very alkaloids that make monarchs distasteful to birds and they produce extremely sticky latex sap. Monarch caterpillars have evolved to tolerate and even utilize the alkaloids but newly hatched monarch caterpillars are often engulfed by the sticky latex sap that gushes from a leaf when the tiny caterpillar starts to feed. One researcher estimated that 60% of newly hatched caterpillars were victims of milkweed sap during their very first attempt at feeding. They were killed by the milkweed’s defenses. And, they only eat milkweed. They have no choice but to eat it.
Even after all of the dangers that a monarch caterpillar must face it has been estimated that 10% will grow to full size, pupate and become butterflies.
Under normal circumstances, insects can stand heavy predation because they reproduce explosively. A female monarch may lay as many as 400 eggs. If 200 of those eggs produce females and each of them lays 400 eggs … well, you get the picture. Insects reproduce in great numbers and are eaten in great numbers. And, generally, enough survive to carry on the species.
However, researchers who estimate populations of overwintering monarchs in Mexico by counting the number of hectares of oyamel trees heavily covered with dormant butterflies believe that populations have been in decline for decades. There have been numerous theories put forth to explain their decline but no smoking gun has emerged. No single cause.
The monarch, Danaus plexippus, is probably one of the most studied species in the world. We know many ‘facts’ about it but we’re not even close to understanding its multigenerational continent spanning realities, and we may never be. And we’re not even close to understanding our impacts on the species. But the more I read the more I respect the monarch, Danaus plexippus, AKA The Wanderer. It’s a survivor. At least so far.
Dear new and returning Dummerston Monarch Welcoming Committee,
Saturday, June 19th was the official start of our 2021 project. I spent three hours at the beautiful Bunker Farm distributing swamp milkweed plants (free, thanks to an AVCC grant), saying hello to those of you returning for the second year of the project, and welcoming 7 new participants/families. I gave away all but a few plants. If you want more, hurry over to Bunker Farm in the next day or two.
Over the course of the season, you will receive emails from me about a variety of topics related to Monarchs. If you would like to share information, photos, videos, articles, etc., please respond to all. However, if you have a specific question for me, please do not copy all. I want to save you from getting too many unnecessary messages.
Since this is the first message for the 2021 project, I want to make sure I cover lots of ground, and I apologize in advance if this is repetitive for some of you. The information I share will also be posted on the Dummerston Conservation Commission website, along with information I provided to participants in 2020. We have our own blog!
For those of you planting swamp milkweed for the first time, I recommend you plant it among flowering annuals and perennials that attract pollinators. If you want to easily see Monarchs in action at all stages of their life cycle, plant the swamp milkweed not too far from your house. Full or part sun is fine. It is happy in any kind of soil, but will need room to get big over the next few years.
Two weeks ago, I participated in a Zoom training to collect data for the Monarch Larva Monitoring Project (MLMP), which is a national program sponsored by Monarch Joint Venture. After the training, I spoke with outreach coordinator Julia Whidden and described to her our community project. Since MLMP uses data collected from citizen scientists all over the country to understand Monarch population health and trends, she is encouraging anyone interested to get trained and begin collecting data. The expectation is that you will monitor once a week throughout the season. Information about online training which you can do at your leisure is on this Google drive link. MLMP and Monarch Joint Venture are terrific resources!
Regardless of whether or not you decide to officially monitor Monarch larvae in your garden, make sure you have a magnifying glass and a notebook or sketchbook handy so you can keep your own records. It’s fun to look back week to week and year to year. Also, take lots of pictures!
If the Monarchs do indeed show up, I will invite small groups of you to my garden so we can have an opportunity to practice larva data observation and collection. I will have magnifying glasses and some cool materials for you to use while you’re here. Workshop dates and times TBD.
Last of all, but first in significance, a big thank you to Helen O’Donnell for growing such sturdy and beautiful plants for our project!
The DCC was awarded a highly competitive 2021 Tiny Grant of $500 from the Association of Vermont Conservation Commissions (AVCC). As one of seven recipients in the state, the DCC will expand the second year of its project – Inviting Monarch Butterflies to Dummerston – by adding a new cohort of interested Dummerston residents, along with returning participants from the first year. Funds from the grant will help pay for swamp milkweed for participants to plant in their pollinator gardens, attracting monarchs and other valuable pollinating insects. Project members will receive continuous education, mentoring, and participatory experiences focused on pollinator planting and gardening, monarch life cycle identification and data collection, and access to recommended organizations and websites monitoring monarch populations and habitat restoration. Many thanks to AVCC for its support for our project to provide our community an opportunity to participate in the broader movement of climate change mitigation and ecosystem health.