NEBRASKAland Magazine is dedicated to outstanding photography and informative writing with an engaging mix of articles and photos highlighting Nebraska’s outdoor activities, parklands, wildlife, history and people.
Issue link: http://mag.outdoornebraska.gov/i/534597
40 NEBRASKAland • JULY 2015 M ilkweed plants have recently gained a lot of attention because they are the plant of choice for monarch butterfly caterpillars. Loss of habitat and changes in agricultural practices have decreased milkweed populations across the state, leaving fewer places for monarchs to lay eggs. At the same time, if you look at the reproductive strategy for milkweed plants, it's kind of shocking they've survived as long as they have. Milkweed pollination is literally (and I don't mean that figuratively) a series of accidents strung together. That any milkweed plant produces seeds seems nothing short of miraculous. To start with, an insect has to be attracted to the milkweed flower, presumably by the sweet sugary nectar inside. That's not difficult – many insects enjoy sweets, and milkweed nectar seems to be particularly tasty. However, the next step requires the insect to accidentally step into one of the tiny slits between the anthers on the side of a blossom. There is certainly no incentive for the insect to do that, in part because those slits can be tight enough that insects can't always get their leg back out. Once the insect's leg is in the flower, it will immediately try to extract it. As it does so, it may snag a pair of waxy orange gobs of pollen called the "pollinia" with its foot. That's the critical next step of the process for the milkweed. If the insect pulls its leg out without pollinia stuck to it, the milkweed loses. However, even if pollinia stick to the leg of a visiting insect, the milkweed hasn't yet won. In order to complete the pollination process, the pollinia have to be deposited inside a different flower – hopefully on a different milkweed plant altogether. This requires a couple of things to happen; the insect has to travel to a different milkweed plant and it has to refrain from removing what has to be a pretty awkward sticky mass hanging off its leg before it makes that trip. Assuming an insect makes it to another flower with the pollinia still attached, there are still several steps A Series of Fortunate Accidents The pollination strategy for milkweed is so impossibly crazy there's no way it should work. By Chris Helzer The abundance of milkweed seeds floating around in the fall shows that the accidental pollination strategy of milkweed is successful. This giant milkweed bug (on butterfly milkweed) already has pollinia stuck to two of its legs. e t i A w t c t l m l h t h f m r t m f a l a a This giant milkweed bug (on butterfly milkweed) already has pollinia stuck to two of its POLLINIA The abundance of milkweed seeds