7.19.2007

Got Milkweed?

I’m glad I asked the farmer’s son not to cut the humble stand of milkweed along the barbed wire fence. Twice a summer, the local dairy farmers hay the field for cow feed and bedding. If the weather’s right and the field’s growing well, they might just get a third cut in.

But the honeybees have been so enjoying the 207 milkweed plants (yes, I counted them), that when I heard the tractor coming up the road for the second haying of summer, I ran outside to intercept. I pointed to the purple flowers and asked the driver—the farmer’s 12-year-old son—to please spare them. The kid visibly recoiled when I explained that I’d started beekeeping and that the bees really loved those flowers. Thanks to his kind compliance in mowing around the milkweed-populated edge of the field (probably in large part to avoid the dreaded bees), the frenzied action on the milkweed blossoms has continued unabated for more than two weeks now.Along with the pleasure of watching dozens of honeybees visit the milkweed blossoms, there is the delight of listening to the satisfied work-sound of the proverbial busy bees. Several times a day, I find myself drawn up the hill to the milkweed stand to receive a dose of "happy buzz" therapy. The bees softly rising and landing on the blossoms, the hazy-sweet aroma permeating the area, and the concerted hum of bees fulfilling their life’s mission are quintessential expressions of summertime—the place I want to be.

The bees have drawn me to the milkweed, but the milkweed has turned out to hold a fascination all its own. Its a pollinator-magnet, hosting a kaleidoscopic array of life forms so fascinating I’m seriously considering a mid-life career shift to entomology.

Milkweed also has a nefarious side, as we'll see in a moment. But first let's walk on the sunny side of the Milkweed Street and say howdy to some of the many denizens of and visitors to this remarkable plant.

Many of us know milkweed as the host plant for the famed monarch butterfly, which (unfortunately) has proven too nimble and elusive for this paparazzo. I have been able to catch the monarch in its caterpillar form: an unparalleled example of the marriage of style and substance.

Other, less camera shy butterflies have been enjoying the milkweed as well.
The Great Spangled Frittilary

The Eastern Comma (At least I think it's a comma. If there are any serious bug people reading this, please feel free to correct this or any other inaccurate IDs.)

Some kind of Hairstreak (possibly Edwards)

The Eastern Tiger Swallowtail

Some type of skipper.

Some other kind of skipper.

There have also been many moths, including one of my day-flying faves, the Virginia Ctenuchid Moth.

But the real revelation was going to visit these plants at night. Hundreds—and I mean hundreds—of moths gather there, making the daytime scene look subdued by comparison. My night shots aren't so hot, but you get the idea.
The cast of characters seen during the day also includes...The Small Eastern Milkweed Bug

The leafcutting bee (I think that's what it is)

A drone fly.

Japanese Beetle

A bee-like fly?

Golden Northern Bumblebee (I think—in any case, it's adorable!)

Milkweed Longhorn

Green Stinkbug (Note that the lower part of the insect's left leg is missing. Also note the little yellow "droplet" adhering to its right leg. The story behind all this will soon be revealed.)

An unidentified dragonfly.

A beetle and an ant.

Some kind of bumblebee?

Hornets and wasps of various kinds.

Now let's turn our attention to the aforementioned "nefarious" side of milkweed. WARNING: Some of these images are of a graphic nature (pun intended)—and may upset small children or exceedingly sheltered adults.

Some weeks ago, much to my horror, I began to notice honeybees entering the hive with tiny bright yellow "spokes" attached to their feet, giving the appearance of some kind of deformity. These bees were "limping" into the hive, dragging their feet in a most disturbing manner. In most cases, the deformity appeared on one or both of the hind feet, but sometimes it was apparent on the front feet as well, as in the case of this poor bee.Needless to say, I freaked. I then proceeded to spend a quiet, anxiety-filled evening Googling variations on the terms honeybee foot deformity, honeybee foot anomaly, honeybee foot anatomy, honeybee foot fungus, honeybee medical conditions, and honeybee disease. Like a first-year medical student studying malady after malady, it wasn't long before I started experiencing symptoms of the many horrid honeybee diseases out there. However, nothing I found resembled the strange foot disorder.

Luckily, my Organic Beekeeping listserv once again came to the rescue. Someone on the list explained that if milkweed was blooming in my area (and it was), the foot "deformity" might actually be little pieces of milkweed pollen that had gotten stuck on the bees' feet. Sure enough, the very next day while perusing the milkweed I found a dead bee with these bits of pollen stuck to both her hind feet and forefeet. During the same visit, I got this photo of a bee working the milkweed blossoms with this strange botanical material attached to her feet and proboscis.
I also began to notice that various insects, including honeybees, flies, and moths, were becoming "stuck" to the blossoms. Here, a fly struggles to extricate its foot.
It seems the milkweed plant extracts a price for access to its alluring nectar. According to a delightful book published in the 1920s called Honey Plants of North America:

"Milkweed flowers are called pinch-trap flowers because they possess a remarkable clip-mechanism found in no other family of plants. Two club-shaped masses of pollen are attached by flexible bands to a small, dry, triangular disc placed midway between them. In this membraneous disc there is a wedge-shaped slit at one end. In its effort to obtain a foothold on the smooth flowers an insect is likely to thrust a claw, leg, antennae, or tongue into one of the slits. If one of these organs is drawn upward in the slit, the dry disc becomes tightly clamped to it. When the insect flies away it carries with it the disc and the two masses of pollen strapped to it. Exposed to the air, the strap-like stalks dry and draw the pollinia close together. As the insect alights on another flower, they are easily thrust between two anther wings, where they come in contact with the stigma; but, once inserted and pulled upward, they can not again be withdrawn. The insect can obtain its liberty only by breaking the connecting bands. If it cannot do this, it perishes slowly of starvation. Disc after disc may thus become attached to an insect until it is crippled or helpless."

Here's a closer look at the "ball and chain" structure in question. Note the tiny black string of "beads" attached to the bee's feet, as well as the bright yellow pollen.

A captive moth struggling to escape. Milkweed Street is rich in colorful characters, but not without its sad dramas.

A moth that didn't make it. Note the moth-dust on the three surrounding buds: evidence of a frantic, protracted struggle.
A limb sacrificed for the greater good.
After my psychodrama with Google, I felt a little less alone when I read the remainder of the entry in the Honey Plants book:
"Not a season passes that inquiries are not received from beekeepers requesting information in regard to these peculiar appendages; and many explanations of them have been given by persons not familiar with the flowers of the milkweed. Some regard them as a fungus, others as a protuberance growing on the bee's leg, and still others as a winged insect-enemy of the bee."
And here's what it's all about: once pollinated, the flower morphs into a tiny pod that grows to become the familiar, canoe-shaped milkweed pod that cracks open in fall and spreads its silky-topped seed pods through wind dispersal.
The milkweed—its pedestrian, somewhat demeaning name notwithstanding—turns out to be a rather exciting plant: sweet-smelling and good-looking enough to attract a dazzling array of pollinators, unique in its role as the sole host plant for the glorious monarch butterfly, and clever enough to have evolved a form of pollination insurance unique in the plant world.

The humble stand of milkweed at the edge of the field has turned out to be a most intriguing spot to hang out this summer. Like I said, I'm glad the farmer didn't cut it down.
***
A weathered old honeybee with tattered wings works the milkweed blossom.

13 comments:

Abelisto said...

Fascinating post. I loved the photos. I think I'm going to take a trip sometime this weekend to a local patch of milkweed and do some observations myself.

Gerry Gomez Pearlberg said...

Many thanks! Let me know how it goes and perhaps post your insect-findings on your blog? I'll be checking....

Julie R. Enszer said...

We had a patch of milkweed growing right by our house where I grew up in Michigan - a city. The milkweed attracted hundreds of monarch butterflies, which I loved as a child. Then one day I saw birds eating the Monarchs, which in itself was disturbing, but then those same birds immediately became sick from eating them and vomited the butterflies. It was a sobering experience of watching nature.

This is a great blog! I look forward to reading more of it!

Julie

NatureGirl said...

I hope you don't mind, but I swiped your decription of the milkweed's pollination strategy for my blog - gave you and your blog full credit. I had read about this a couple years ago, but couldn't find a good source today to use in my blog, until I found yours. Thanks!

Gerry Gomez Pearlberg said...

Naturegirl--Glad you could use the info and thanks for crediting Global Swarming. Pretty incredible adaptation, eh?

Anonymous said...

Yes great information. I happen to grow Milkweed exclusively for the benefit of the Monarch Larvae. I do my best to rear them. I have my share of insects shown here that come and visit my 20 or so Milkweed when they are in bloom. And yes specially bees.

I have yet to see the phenomenon you describe, regarding the pollen on the feet of the insects. Given what I know about milkweed, makes total sense. I do have a peculiar problem which is very similar in nature. ….. I breed the monarch larvae to adult butterfly to release them. I try to control the larvae’s destruction of the entire milkweed plant by placing them on plastic container and feeding them a control number of leaf @ a time. Rather than allow them indiscriminately eat which ever leaf they want. Frequently, the larvae leaves a lot of leafs uneaten to dry. My problem is also with the milky latex substance and the strings of fiber latex created by the larvae themselves (not the flowers, but they seem to be similar) The Larvae usually use it to attach themselves when they go to pupa. They seem to be creating these latex fibers all the time. Often I see the larvae uses it as a glue so the can walk upside down on the leafs. Some times I see these fibers all over the inside of the plastic containers. Other times I see them use it as a way of coming down like a spider from leaf to leaf or if they fall down by a forceful wind or strong rain to soften the fall. They seem to use it as a safety rope.

As you know these larvae are eating machine and they defecate a lot. I have to clean the containers very frequently. When they are active, I need to clean @ least every hour. If have a lot of larvae in the container and I neglect to clean the container quickly enough, the latex fibers full of soil are seen all over the inside the containers and I have to immediately clean the problem. Larvae do make a big mess with this latex. The latex comes from the chewing on the Milkweed leaves. The big problem is that the frass (poop) of the larvae become attached to their feet. Sometimes causing problem to remove the and clean container.


I have been wondering about Aphids who also invades and sock the substance from the Milkweed plant. I have wondered if aphids get the same defense that the monarchs and its larvae get from consuming Milkweed product. I have been seeing Lady Bug Beatles around the milkweed that is being acted by Aphids and they do not seem to be actively eating them

amarilla said...

Amazing post. It is, as you write, "An unparalleled example of the marriage of style and substance."

Carol said...

Wonderful post! I have written about this sad phenomenon before but wanted to focus more on it with a new post. I found you through googling about attached pollen to honeybees feet. Great photos of the many visitors to Milkweed. I once tried to help a honeybee and it actually let me . . . but could not free the handcuff like pollen. Even the florets have a rather hauntingly beautiful nature with the claws reaching out from the horns. Glad to have found your blog. I have wild honeybees that live in my old Rock Maples . . . for years now. I have been lucky to see and record swarms too. Fascinating to live so close to these amazing creatures. ;>)

Gerry Gomez Pearlberg said...

Thanks for the kind words, Carol. I'm glad you found the post and enjoyed it. How wonderful to have wild bees on the premises, and to experience the incomparable excitement of witnessing swarming. Nothing quite like it!

rusty rice said...

I just found your site and you gave more info than anywhere else I have found. I have been gardening for many years and have noticed a great decline in "good bugs" so we have tried our hand starting a honey bee colony and planting various flowers to attract "good bugs". we lost our colony due to rogue bees. But we will try again with a new one this coming spring. My question is should I plant the milkweed away from other flowers? Will it choke out other unwanted weeds? Oh and do any of the toxins transfer to the honey?

Gerry Gomez Pearlberg said...

Hi Rusty,
Glad to hear you found the information useful. I doubt you'd wind up with enough milkweed to affect the honey crop, but yes, I might suggest planting the milkweed in its own area in drifts large enough to be visible to and attract pollinators of various kinds. I think a lot of different environmental organizations are trying to increase awareness about the importance of growing milkweed. It's been decimated by farming practices and over-development, so I'm sure your efforts will be appreciated by the local critters.

David d'Entremont said...

Wonderful post (even now in 2015!). Having noticed this phenomenon of milkweed "pollen tags" on pollinator feet and seeing pollinators get stuck on milkweed flowers, for the longest time I never ended up learning what was going on. I found your post very useful in finally answering that question.

In thanks, being something of a "serious bug [person]" that you alluded to in one of your captions, I can confirm and correct at least some of your photo ID's :)

Great Spangled Fritillary (Speyeria cybele) - correct!

Eastern Comma (Polygonia comma)- The most likely culprit. I find Grey Commas frustratingly similar from above, but due to commonality and spotting characteristics I think Eastern is most likely. Certainly one of these two.

Hairstreak - Certainly a Striped Hairstreak (Satyrium liparops). The off-set white-and-black-lined bands on this species are very broad, whereas Edwards' Hairstreak has lines of small, dainty spots instead. Hairstreaks are hard!

Eastern Tiger Swallowtail (Papilio glaucus) - bad angle, but you're likely right.

"Some type of skipper" and "Some other type of skipper" - though challenging as skippers can be, I believe these are both Dun Skippers (Euphyes vestris) - a male in the first photo (with no wing markings to speak of) and a female in the second, with extremely minimal spotting.This species can appear to have almost no patterning at all.

Virginia Ctenucha (Ctenucha virginica) - yep!

Washed out moth photo 1: There's just enough detail to have confidence to call this a Banded Tussock Moth (Halysidota tessellaris). The other two photos are no good though for ID.

Small Milkweed Bug (Lygaeus kalmii) - yep!

leafcutting bee - no comment (I don't know these enough)

Drone Fly (Eristalis tenax) - yep!

Japanese Beetle (Popillia japonica) - yep!

"bee-like fly" - This is a kind of Hover Fly/Flower fly (Family Syrphidae), and looks to be in the genus Sphaerophoria. Species ID from photos alone won't be possible here. Many Syrphids have a bee-like appearance and visit flowers, and they get the name "Hover Fly" because many have the ability to hover completely motionlessly (apart from wings) just like hummingbirds.

"Golden Northern Bumblebee" - this is likely either Tricolored Bumble Bee (Bombus ternarius) or Hunt's Bumble Bee (Bombus huntii). Golden Northern Bumble Bee shouldn't have 2 solid orange bands.

"Milkweed Longhorn" - yep! Red Milkweed Beetle (Tetraopes tetrophthalmus), from the longhorn family Cerambycidae.

Green Stink Bug - yep! though I can't comment to species.

Dragonfly - This is a young female Meadowhawk (genus Sympetrum), but this one is impossible to determine to species from this photo, as there are several extremely similar species like this that require a hand lens to differentiate between. I would also like emphasize (for anybody reading) that dragonflies are strict carnivores - this female was likely perched for the purposes of sunning/waiting to spot new prey. Dragonflies do not take nectar from flowers.


Beetle and ant - I can say that the beetle is a Click Beetle species (family Elateridae), but nothing more. I know even less about the ant!

And that is basically the extent to which I can help.

Wonderful post! Hopefully you're still keeping tabs on the message board :D

Gerry Gomez Pearlberg said...

David, Thank you for this wonderful response...and for taking the time and trouble to go over my photos and provide such helpful IDs and explanations. Your comment made my day!