Monday, July 14, 2008

Life on a Milkweed

I headed out to our butterfly garden to snap a photo or two of the milkweed flowers to use for my Plant of the Month this month and got completely wrapped up in all the life on the milkweed! The more I looked, the more I saw. Ants, bugs, beetles, bees, spiders, moths, butterflies...the list went on and on. Here are some images of what I saw:

I think this is a flower spider (Misumena spp.). If so, the neat thing about these spiders is that they can slowly change their color (presumably to blend in with the flower on which they are hunting). This one seems to have successfully caught an ant.

I've seen this lovely beetle before. This one was skulking around the flowers of the milkweed, but fell onto the stem as I was jockeying for a better photographic position. Thanks to the marvels of modern technology (the Internet), I now know that this is a Labidomera clivicollis - Swamp Milkweed Leaf Beetle.

This white admiral butterfly (Basilarchia arthemis) has seen better days. Behind it a variety of ladybug is creeping along a blossom.

And here we come to one of the facinating things about milkweed: its pollination strategy. Rather than tyring to paraphrase the entire process as I found it on, here is not only the link, but also the text that the owner of this blog copied down from her (his?) copy of a 1920s book titled 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anther wings, where they come in contact with the stigma; but, once inserted and pulled upward, they can not again be withdrawn.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."

Now, then - take a close look at the feet of the bumblebee above. Do you see the yellow bits by its feet? Those are the pollen bits that have detached from the plant and stuck to the bee's feet. This robust bumblebee seems to have been able to escape from its floral traps, but can you imagine being permanently caught by the foot by a flower? Kind of makes you stop and think, doesn't it?

Still, it is a lovely flower.

1 comment:

  1. Nice to discover your blog, northward neighbor. Thanks for linking to Global Swarming Honeybees.