the Monarch magnet

Meadow Blazing Star attracts butterflies like catnip attracts cats. They stay on the plants for hours, flying around the flowers, dipping into them, chasing each other, and just generally hanging out by the vibrant purple blooms. I highly recommend it for your garden.

Monarch butterflies are especially fond of this tall (about 5 feet) spike of purple-pink blooms that are so highly visible and last such a long time in the garden.

The individual flowers of meadow blazing star are densely packed on a very long stem. I don’t know if this species of Liatris has more nectar than other blazing star species, but there are so many flowers and such a long blooming time, it provides a stable nectar resource for all sorts of insects.

An occasional bumblebee might try to land on these flowers, but the Monarchs usually chase them off.

We found an isolated stand of meadow blazing star in a prairie area at Fort Ridgely State Park on the Minnesota River near New Ulm, and this stand too, was a magnet for the Monarch butterflies with more than a dozen of them flying around the flowers continuously.

These Monarchs are most likely the final generation of the summer — the individuals that will fatten up on rich nectar resources from blazing star and other flowers and then begin a 2-3,000 mile journey to their overwintering sites in montane forest areas of central Mexico. Flying about 50-100 miles a day, it will take them more than two months to complete their migration. They depend on finding more nectar resources as they travel south through the American midwest, then south to Texas, and on through northern Mexico — an amazing feat of stamina and navigation in order to return to their overwintering site.

Mid-summer scenes

Mid-summer, it’s the time when fruits are ripening, profusions of flowers light up backyards and prairies, and we see lots of birds, butterflies, and bees everywhere.  It might be hot and sticky, but this is the time we’ve been thinking about on those cold winter days.

Monarchs have made it to Minnesota by July, and begin laying the generation of butterflies that may be the ones to migrate south in a couple of months.

Lake water warms up, and mats of water lilies and duck weed clog the shorelines.

Warm summer days, scenic Minnesota lakes, one of the more than 10,000.

Butterfly milkweed is in full bloom, attracting butterflies and bees.

Sandhill Cranes may have chicks following them around through the prairie meadows, and occasionally you see and hear them fly overhead.

Fruiting heads of smooth sumac light up the green forest of sumac shrubs. Did you know that the seed heads are high in vitamin C? Crush them in water to make sumac-ade!

The black morph of the Tiger Swallowtail butterfly has been visiting the backyard garden this week. It must be relatively newly emerged, with no bites in its wings yet.

What’s not to love about mid-summer days in the Minnesota backyard?

A good omen

I count it as a good omen that the first animal I saw on this trip to Peru was a Monarch butterfly.

Monarch butterflies are probably resident year-round here in this equitable climate.  I hope these populations are healthier and more numerous than the ones that migrate to the U.S. from Mexico.

Walking among the high rise buildings and city industry of the Miraflores area of Lima, the only living things to be seen were people and plants.  So when we stumbled across a park dedicated to the fallen defenders of the city during the War of the Pacific between Peru and Chile in 1881, I was delighted to find a few birds in the trees and a few Monarchs nectaring on the Lantana blossoms.

One of many statues in the park commemorating the fallen defenders, some of whom were apparently young children.  Colorful buildings, too.

Garden beauties

The wildflowers are at almost peak color and diversity in the backyard, and happily this year, quite a few butterflies have made an appearance there for the first time in several years.

It’s always great to see Monarch butterflies flitting about — this beautiful female spent far more time sipping nectar from the coneflowers than she did laying eggs on the milkweed. Numbers of Monarchs have dipped precipitously in the last few years, due to a number of stressors along their migratory route.  Hopefully this will be a good year for Monarch production.

A well-worn Red Admiral with a rather large bite out of one of his wings is one of several of these butterflies that frequent the coneflowers in the backyard.  This is one species that does not seem to have suffered population declines in recent years.

An American Lady (sometimes erroneously called Painted Lady which is a different and related species), with its bright black and blue spots on its hind wing, is closely related to the Red Admiral.  This is another very common species across the U.S.

Part of its forewing looks just like that of the Red Admiral, but those two big eyespots are unique to the American Lady.  The butterflies we see in MN (and other parts of the northern U.S.) are most likely offspring of more southerly distributed butterflies that migrated north in the spring.

Great Spangled Fritillary butterflies are another widespread species across North America.  It’s one of the larger butterflies (> 2 inches), a little larger than a Monarch.  Larvae feed on native violets — plenty of those in the backyard.

With its combination of black slashes on the top of its orange wings and large white ovals on the other side, it can be difficult to tell this species from other fritillaries, but the wide buff band between the two rows of white spots differentiate this species from Aphrodite and Atlantis Fritillaries, with which the Great Spangled overlaps in range.

Where the excitement takes place in the backyard…

What else is in the garden today?  A small Gray Tree Frog matches the leaves on which it is resting.

island refuge

Usually we think of islands as delicate ecosystems, sensitive to change because of the few numbers of species there and their complex interactions that can be upset by the loss (extinction) or addition (invasion) of a species.  However, through the introduction of a couple of milkweed plant species, Maui, as well as Oahu and the big island of Hawaii, seem to have become a refuge for Monarch butterflies, whose populations are crashing in various parts of mainland North America.

In the town of Kapalua on the northwest shoreline of Maui, a very hilly and abandoned golf course has become a refuge for all sorts of exotic plants and animals like the Monarch butterfly.

It hardly seems possible that there could have been fairways and greens here once. A forest of Norfolk Island pines and other exotics have completely overgrown everything but the golf cart paths, which now make wonderful hiking trails.  That’s the island of Molokai in the distance.

These lofty Norfolk Island pine forests make welcome cool, shade on a hot, humid day.

Along the edge of the golf cart path, balloon milkweed, introduced from southeast Asia, grows in dense patches. Both flowers and seed pods were present, and dozens of Monarch butterflies flitted in and about the vegetation.

The flower head points downward (unlike other milkweeds) below reflexed petals, so the butterflies have to hang from the flower rather than perch on it. This might make it more likely they will catch their feet on the pollen sacs, removing them and helping the plant outcross its pollen to another plant.

A female Monarch butterfly feeding on the nectar of balloon milkweed attracted the attention of a few males, but fluttered her wings vigorously and drove them off.

Unlike Asclepias species of milkweed we have in North America, this species (Gomphocarpus phytocarpus) sports inflated pods surrounding the tender seeds within.  The air space between pod wall and seeds must make it difficult for seed predators to feed on the next season’s crop of milkweed plants.

Dozens of Monarchs flitted about us as we walked.  I don’t think I have seen this many Monarchs in an entire summer (or two) in Minnesota, but here they are thriving with plenty of the balloon milkweed leaves for the caterpillars to feed on and the nectar of this and other flowering plants in the overgrown golf course to sustain the adults.

It’s possible that Monarchs have become established on the Hawaiian islands by founding individuals from California, but that is a 2400 mile journey, and the wind generally blows from west to east, not the reverse.  Unlike the California population, island Monarch butterflies are not migratory, so once they have found isolated patches of milkweed, populations thrive and increase.  In addition, several butterfly “farmers” in Hawaii market their Monarchs for weddings, with additional individuals being released to the island as the couple pronounce their vows.

So here’s a rare story of how an introduced plant species benefits the survival of a species that is threatened in other parts of its range.  It’s a wonder how the butterflies find their milkweed hosts (needle in a haystack?), but impressive when they do.

Not hiding in plain sight

Brightly colored animals seem to flaunt the potential danger of being someone else’s dinner.  Calling attention to themselves with bright colors and flashy appendages seems counter-intuitive to survival.  So why do it?

It’s all about the advertising.  Bright color can be a warning to other animals.  Don’t eat me:  I’ll make you sick, my bite is lethal, I have a wicked sting.  You’ve undoubtedly seen these types of warnings in your garden.

Monarch butterfly orange and black warning coloration stands out on any background, but especially well on the purple blazing star. Photo by Karen Eckman

Some animals copy these bold aposomatic patterns, hoping to mimic the warning signal closely enough to avoid predation themselves.  Many insects copy the yellow and black warning coloration of bumblebees, hoping to fool a potential predator.

The things that sting have bright yellow and black coloration; some have fuzzy hair and some don’t — even that pattern is copied.

The mimics might even try to act like their models — hovering in front of flowers (hoverflies) or between perch sites (robberfly)

Some brightly colored fish purposely flaunt their colors to signal that they have a service to offer to others.

A brightly colored bluestreak cleaner wrasse hovers near the much larger and cryptically colored puffer fish to pick off parasites and extraneous food bits as a cleaning service.  Bright colors advertise the service at this “cleaning station”.  Photo from Wikipedia.

Bright colors in birds, especially the brightly colored plumes or other adornments projecting from their bodies, are a different kind of advertising.  By calling attention to themselves, colorful male birds are advertising their potential as a parent, or even just a sperm donor.  It’s as if they are saying to females, “I can survive in spite of attracting the attention of predators, or in spite of all these silly plumes that compromise by ability to escape, so choose me”.

A male peacock’s size may deter some predators, but all a predator has to do is grab hold of that long tail, and the advertisement becomes a liability.  Typically, the peahen raises the chicks, so all this male is advertising is his vigor (and sperm) as a potential mate.

Male Cardinals advertise more than just their vigor and ability to escape predation.

Bright colors mean the bird is in good health, and are an indication that these birds know where to find the food that makes them healthy, as well as brightly colored.  A female cardinal might choose one male over another for his ability to feed their chicks the right kind of food which, in turn, enhances their survival.  The female’s choosiness thus drives the male color pattern and feather adornments — sometimes to ridiculous or risky levels.  But if a flashy male survives the risks, then he’s the one.

Kit Day’s birds of Gambia:  

Specialists

Isn’t it strange that a plant that contains so many nasty chemicals (e.g., cardiac glycosides), as well as rubbery latex so alkaline that it can permanently scar the cornea of one’s eye, has so many insects that specialize on it?

But here they are — the amazing milkweed fauna:  lepidopterans, bugs, and beetles, consuming every part of the milkweed plant from its roots to its seeds — all seen in the backyard this summer.

The familiar Monarch butterfly caterpillar, munches away happily undeterred by the milky latex exuding from the leaves and stems of the plant.

The less familiar Milkweed Tussock Moth larvae — there were so many caterpillars on this particular milkweed plant, they completely defoliated it.

The tussock moth larvae grows some very long tufts and is not quite so gregarious when it’s older.

Milkweed bugs (true bugs — Hemiptera) are usually found on milkweed plants that have formed seed pods. They lay a clutch of bright yellow eggs on one of the pods, and the nymphs develop through five molts into adults by feeding through the pod wall on the seed endosperm.

Yellow aphids collect on milkweed stems and pods, but feed on the sugars passing through the plant’s phloem vessels, not the seeds. Small wasps (left center) parasitize the aphids by laying their eggs on the host.  Aphids are actually true bugs (Hemiptera), although these non-winged individuals don’t appear very bug-like.

The Red Milkweed Beetle is a member of the long-horned beetle family. They lay their eggs near the ground, and the larvae burrow into the roots and develop and overwinter there to emerge as adults the following spring.  Like the monarch butterfly larvae, milkweed beetles incorporate the milkweed’s poisonous chemicals into their own bodies, becoming distasteful to their predators.

Milkweed leaf beetles are members of the very large leaf-beetle family. They eat the leafy greenery, but the larvae are also known for consuming each other — their cannibalistic tendencies reduce competition for food in their local area!

Isn’t it ironic that in producing poisons to ward off herbivores, the plant becomes more attractive to specialist herbivores also trying to avoid predation?

moth vs butterfly

Usually it’s easy to distinguish a moth from a butterfly. Moths are generally nocturnal; butterflies operate in the daytime.  Moths have furry, chunky bodies; butterflies are sleeker with less “hair”.

A white-lined sphinx moth warmed itself on my outdoor light fixture late one night.

Hummingbird clearwing moths feed on flowers open in the daytime — so, the nocturnal-only attribute for moths has many exceptions.

How about this diurnally-active leadplant flower moth?  Easy to confuse with a butterfly, except that butterflies usually hold their wings vertically at rest while moths rest with their wings outspread or in a V-position, like the wings of a jet plane.

A Monarch butterfly sips nectar from the flowers of a rough blazing star plant. On chilly days, butterflies might bask with their wings open, but usually they sit with the wings vertical at rest.

Butterflies generally have slender, clubbed antennae; moths sometimes have elaborate fringes on their antennae or have slender filamentous antennae without clubbed ends.

Ropy antennae with clubs on the end are characteristic of most butterflies, like this Red Admiral feasting on a coneflower.

The elaborate, feathery antennae of the male silkworm moth can detect the bombycol molecules released by a female moth from a mile away.  Photo by Ash Bowie from Wikimedia Commons.

As expected, the compound eye of moths differs from that of the butterfly — each being highly adapted to the light intensity of the environment in which the animal is most active.

Butterflies generally have compound eyes adapted for color vision in bright light, with multiple darkened areas that probably represent clusters of ommatidia used as specific focal points.

The compound eyes of moths are specialized for visual acuity in dim light. They appear more uniform in color, lacking the dark spots seen in the butterfly eye.  Note the slender, filmentous antennae of this moth — very unlike a butterfly’s.

A final important difference between butterflies and moths is the pupal case, which may be a smooth chrysalis in butterflies but is a webby, textured cocoon in moths.

But then just to confuse things a little, we have the hairy-bodied skipper butterflies, with their densely haired bodies and their habit of sitting with wings spread rather than vertical.  But ropy antennae with clubs on the end means that these guys should be grouped with the butterflies.

You can read more about this group of butterflies here.

the Monarch returns

I saw my first Monarch Butterfly in the garden about a week ago.  It sailed around the milkweed plants a few times and took off — perhaps it was a male looking for a mate.   However, yesterday a female Monarch butterfly flittered over the several swamp milkweed leaves laying eggs on a few as she went and then proceeded to try to suck up some nectar from not quite open swamp milkweed flowers.

Typically, Monarch females attach a single egg to the underside of a milkweed leaf, curving their abdomen upwards to contact the leaf surface.  They then move on to another part of the plant or another plant entirely to lay more eggs.

Her wings are looking a little beat up, with bare patches of missing scales on the top surface — it must have been a rough trip north.  She probed many of the flowers, but I’m not sure there is nectar there yet since they are not fully open.

The late summer generation of eastern North American population of Monarchs are known for their round trip migration from U.S.and Canada to the Mexican highlands and back, a trip covering thousands of miles over sometimes arid land.

While the typical lifespan of a newly metamorphosed Monarch butterfly is about two months, butterflies that overwinter in Mexico live at least 6 months, in a state of reproductive and metabolic diapause.  They eventually awaken from their winter lethargy, leave their wintering grounds in March, and move north in search of flowering milkweed and begin to lay eggs.  Recolonization of the most northern areas of the Monarch’s range occurs over the course of two generations of butterflies, each generation moving north hundreds of miles after completing their metamorphosis.  The map below shows the time course of the migration this year.

Click on this image to bring up the original website, and then click on”animated map” at the bottom of the screen to see the steady northward progression of sighted adults and larvae for this year.  Map constructed by Journey North.

I was surprised to see that Monarchs were sighted in the Twin Cities area on May 9, having leapfrogged the state of Iowa, perhaps in one of the warm fronts that brought the warblers north this spring.  Those butterflies would not have found much milkweed or any flower nectar on which to feed.  I saw this happen a couple of years ago when we had a late spring and the monarchs arrived when the milkweeds were still only 10 inches tall.  This was the result of that bad timing.

A monarch butterfly caterpillar tried to complete its development on this tiny milkweed, which was growing too slowly to keep up with demand. Ultimately, the caterpillar failed to metamorphose to a pupa. This photo was taken June 26, 2012.  Timing is Everything!

Coupled with ever diminishing overwintering habitat that support fewer and fewer of their numbers, Monarch butterflies face a northward journey of many unpredictable hazards and climatic challenges.  It’s really quite amazing that enough monarch butterflies survive each year to appear in our backyards.

Timing is everything…

Last year we had an early spring (and not much of a winter), so the butterflies arrived and the bees appeared well before there were flowers to pollinate, or even leaves present as food sources for larvae.  Things were out of sync — badly, and I’m sure the insect populations took a nose dive in Minnesota as a result.

Last year, Monarch Butterflies were faced with laying their eggs on 6-8 inch tall plants. This photo was posted on May 12, 2012.

This monarch caterpillar tried to complete its development on this tiny milkweed, which was growing too slowly to keep up with demand. Ultimately, the caterpillar failed to metamorphose to a pupa.  This photo was taken June 26, 2012, and posted here.

This year, spring was 4-6 weeks late here, and also late perhaps further south of us as well.  We are well into summer, the flowers blooms are peaking in home and natural gardens, but pollinators are rarely found.  My raspberries have bloomed and set fruit, and yet I never saw a bee on the flowers the entire time.  Bumblebees are mostly absent, wasps are a rarity, honeybees and other small bees almost entirely absent.  We do have a lot of bee-mimic hoverflies (Syrphidae) though.

So, I was delighted to find a female Monarch butterfly in the backyard (first one this year!), depositing her eggs on a swamp milkweed plant.  The flower heads were still a couple of days from opening, but she was not trying to insert her proboscis into them anyway (proboscis is tightly coiled in the photo).

She probed the flowers and leaves repeatedly with her antennae (to determine whether it was in fact a milkweed plant?).  The proboscis is coiled up under her head.

Several times I saw her purposely lower her abdomen below wing level underneath a leaf, so I assumed she was laying an egg there.  When I checked those leaves,  sure enough, there were some little cylindrical eggs sticking up from the under surface (one per leaf).  I would have taken a photo, but they were much too small for my telephoto lens.

You can see the curvature of her abdomen better in this photo, and even imagine that there is a little white something being extruded from the tip onto the undersurface of the flower umbel (this is pure conjecture — I don’t know that they would lay an egg in a flower cluster).  Click on the photo for higher resolution of the abdomen.

I haven’t seen many photos of butterflies posted on the various blogs I read, so I wonder if this drought of butterflies is widespread over the U.S. (or other parts of the world) this year.  There are strange climatic swings everywhere that may well influence the insect populations (drastically), and that, in turn, would be devastating for our food production.