Somewhere on your site you mention most animals not liking the taste of milkweed (the toxins) – but that cardinals love it. Due to a neighbors bird feeder and plenty of evergreens, we see loads of cardinals. Is it OK for them to eat? And as for young children around — same Q – though I dont see them wanting to eat it – just good to know.Karen says: First of all about the birds. I think normally the bird would get sick (“upset stomach”), but the cardinals around me seem to love eating the monarch caterpillars. Maybe they develop an immunity or it isnt that strong of a toxic to them. As far as the children go, the research I did said that both for adults and children – the milkweed sap (milk) can be an irritant. It can irritate the skin (I havent had a problem with this), but more importantly do not rub or touch your eyes after you have been handling milkweed (especially milkweed sap). It can be harmful to the eyes. If you accidentally get some in your eyes, rinse thoroughly right away. So just make sure the kids wash their hands right after touching the milkweed.
Exploring Nature’s Connections Search
The connection between monarch butterflies and milkweed is among the most well-known relationships between animal and plant species. It is possible to witness monarch butterflies nectaring on a variety of milkweed species.
However, they also drink at a wide range of other flower species, so this isn’t unique.
What makes this relationship so remarkable is the monarchs’ reliance on milkweeds as the only source of food for their caterpillars. In order to protect themselves from predators, monarch butterflies, like many other insect species, have evolved to specialize in eating caterpillars as their larval food source. They do this by ingesting chemicals from the plants they eat. Heart glycosides, found in milkweeds, are poisonous to a wide variety of bird and mammal species. These compounds are defense mechanisms that plants have developed over time to keep predators away from them. This has generally worked for the plants. The primary goals of plants are to live and procreate in order to ensure the survival of their species.
Such a plan for protection is never completely foolproof, however. Because they can digest these plants and store the toxins in their bodies, monarch butterflies and a few other insect species have evolved to be poisonous to humans who are foolish enough to try eating them. In addition to possessing toxic properties, these insects have evolved vivid colors that serve as an easy-to-remember warning to bird or mammal predators to steer clear of them before trying to eat them again. In return for the protection they receive from consuming milkweed, monarchs are taking a gamble on the availability of this food source. Without it, Monarchs wont survive.
Monarchs are not alone in their use of Milkweeds. A wide variety of butterflies visit their flowers to sip from their abundant nectar offerings, including Eastern Tiger Swallowtails,
to the smallest skippers.
Swamp Milkweed (Asclepias incarnata)
and Butterflyweed (Asclepias tuberosa)
butterflies, bees, and other nectar-feeding insects love as well as other milkweed species for their dependable, sweet, high-energy food.
Although they assist the plants in pollination and receive food from milkweeds, butterflies are not the most effective pollinators of milkweeds. Pollinia, or bundles of pollen, are found in milkweeds and are connected in pairs by a thin filament. An insect appendage that is placed in the ideal location within a flower is captured by this connector. To help the plant with cross-pollination, an insect must approach the flower in a way that will engage the filament connecting the pollinia and be strong enough to remove the pollinia from the flower. Using the same mechanism, the insect transports the pollinia to another flower and inserts it there.
Take a look at the Eastern Comma below. It is perched atop a flower and is consuming nectar from a Common Milkweed (Asclepias syriaca) flower with its straw-like proboscis. A butterfly isn’t likely to assist this milkweed in pollination with this method.
In contrast, this bumblebee is facing the flower and has its left front leg inserted right where the pollinia are kept. This bee is interacting with the pollen sacs and is heavy enough to be able to pull them off of the flower by clinging to its leg.
The yellow pollinia attached to the bee’s left front leg is visible if you examine it closely in the picture below.
Bees of a large size, like Carpenter and Bumble bees, are some of the most effective pollinators of milkweed. Common milkweed flowers emit a strong scent that draws bees and aids in their reproduction.
Numerous other insects, such as the Snowberry Clearwing Moth (Hemaris diffinis), benefit from the abundance of nectar provided by milkweeds.
Theres another insect species dining on this Swamp Milkweed. You might be thinking, “Eeuuw! Aphids!” if you see the tiny yellow creatures on the stem. If so, you would be partially correct. These are Aphis nerii, or oleander aphids, a species that is commonly found on milkweeds. However, you might want to reconsider the “Eeuuw!” Aphids actually play a crucial role in the food chain.
Aphids rarely really harm a plant. And they provide honeydew, a tasty excrement that ants adore, as a sustainable food source. The ants protect aphids in exchange for this tasty meal. Ants are necessary for breaking down plant debris, spreading seeds, aerating soil, and occasionally shielding plants from other predators.
Aphids are also a food source for other insects. This Oleander Aphid in the picture below is being parasitized by two predators at the same time! A Convergent Lady Beetle (Hippodamia convergens) larva is biting it in the butt (abdomen), with the intention of eating the aphid. Additionally, take note of the aphid’s bulge on its lower left side. That is most likely the outcome of the aphid being parasitized by a braconid wasp. The aphid is laid inside by an adult female wasp, and its progeny eats the aphid from the inside out, leaving behind an empty husk. Stories about vampires and zombies might get their inspiration from insects! (I’ve yet to identify the white, squiggly thing on lady beetle larvae, but I assume it’s a predator as well.) If you know what it is, let me know!).
If you’re very perceptive, you might have noticed that the scene was depicted on only half of a leaf of common milkweed, with the right side missing. It’s the manner in which Milkweed Tussock Moth (Euchaetes egle) caterpillars feedtidily chewing side by side, stopping at the midribif you’re wondering how that happened.
The Red Milkweed Beetle is another insect that consumes milkweed leaves (Tetraopes tetraophthalmus) This crafty organism nibbles a few places near the leaf tip through the leaf’s midrib. This prevents the milky latex-like sap from flowing to that area of the leaf, allowing the beetle to consume it without having the sticky material cling to its mouthparts.
Insects such as the Large (Oncopeltus fasciatus) and Small (Lygaeus kalmii) Milkweed Bugs eat even the seeds of the plant. Adults may also consume nectar.
These insects’ vivid colors serve as a warning to birds and mammals not to eat them. But they are not deterred by insect and arthropod predators such as praying mantises (or mantids), wasps, assassin bugs, spiders, or lady beetles. They might also eat foliage and seed feeders in addition to nectar feeders.
It is safe for birds and other predators to eat many of these predators. Insects make up a significant portion of a bird’s diet, particularly when it comes to rearing young.
Milkweeds also help birds by providing materials for their nests. A Goldfinch’s nest may have a soft lining made of the fluffy hairs that are connected to the seeds.
Strong fibers found in the stems of most milkweeds are also used by birds, such as Northern Orioles, to weave nests.
The Monarch butterfly’s continued existence depends on milkweeds. They provide a plentiful supply of nectar for our struggling bee populations and serve as food for numerous other beneficial insects. They provide birds and other animals with nest material and insect protein. Milkweeds are essential to monarch butterflies as well as many other species.
Resources
Eastman, John. The Book of Field and Roadside. 2003.
Eastman, John. The Book of Swamp and Bog. 1995.
Eaton, Eric R. ; Kauffman, Ken. Kaufman Field Guide to Insects of North America. 2007.
Harrison, Hal H. Eastern Birds Nests. 1975
Tallamy, Douglas W. Bringing Nature Home, 2007,
You say somewhere on your website that although cardinals adore milkweed, most other animals don’t like the taste of the toxins in it. We see lots of cardinals because of our neighbor’s bird feeder and the abundance of evergreens. Regarding small children nearbysame question, though I don’t see them wanting to eat itis it okay for them to eat? Karen says: First of all about the birds. Normally the bird would probably become ill (“upset stomach”), but the cardinals in my area seem to enjoy feasting on the caterpillars that become monarchs. Perhaps they become immune to it, or perhaps the toxin isn’t that strong for them. Regarding the kids, my research indicated that milk, or the sap from milkweed, can irritate both adults and children. It can cause skin irritation (though I haven’t experienced this), but above all, avoid rubbing or touching your eyes after handling milkweed, especially the sap. It can be harmful to the eyes. If you unintentionally get any in your eyes, immediately rinse well. Therefore, simply ensure that the children wash their hands as soon as they touch the milkweed.
FAQ
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