Ah, the dawn of a new year, the traditional time to make bold pronouncements about how we’re going to be happier/luckier/smarter/kinder/healthier/thinner/more organized. But if the past two years have taught me anything, it’s that there may be more twists and turns ahead of us than we can possibly imagine. This might be the time to cut ourselves a break and just ride it out until we hit calmer waters.
So instead of that, let’s talk about bugs!
Winter can be frustrating for those of us who like to be outside studying insects. The only insects in my garden now are in a deep sleep, tucked away underground or beneath the bark of a tree or in the hollowed out stems of the tall native plants (which I leave standing for exactly that reason). Nothing to see here, move along, come back in April!
So I turn to my books to get me through the dark season. I’ll read anything about insects, fiction or nonfiction, it’s all good. And there doesn’t have to be a storyline; I’ll even read a field guide if I’m in the right mood.
The passing of Edward O. Wilson on December 26 motivated me to read some of his books, as a way to honor the legacy of this extraordinary scientist. Wilson has been called Darwin’s heir for the significant impact of his work on our understanding of the natural world. The title of this blog post is a phrase he used to describe the fundamental importance of insects to all life on our planet. I think of that phrase often, but for some reason I’d never gotten around to reading any of his writing. Until now.
I got two of these books from the library, and purchased the third one, a compilation of three of his works. I’m most enthused about reading Half-Earth, but I decided to start with Tales from the Ant World because I’ve tended not to pay too much attention to ants when I come across them in my nature explorations. The one exception is their relationship with partridge pea (Chamaecrista fasciculata), a fabulous native plant I have in my garden.
There’s a lot to love about this annual native plant — its pretty compound leaves, the beautiful yellow flowers with deep red stamens, and the way it sways gently in the breeze beside my patio. Oh, and the way its brown seed pods twist into spirals in the fall before popping open to scatter the seeds for next year’s crop. I can spend hours watching the bumblebees “buzz pollinating” it on a summer morning. Buzz pollination occurs when the bee uses vibrations to shake the pollen loose.
The flowers of most plants contain both pollen and nectar, so that the insects who visit for nectar will incidentally deposit pollen from other flowers they’ve visited, helping the plant to reproduce. But partridge pea flowers don’t contain nectar at all. The nectar is located separately, in little “extrafloral nectaries” located at the base of each leaf stem. They’re tiny little bowls of easily-accessible sweet stuff. Here’s an ant drinking from one of them:
Why would a flower evolve to allow access to its nectar like this? In most cases, an insect provides some benefit to the plant (pollination) in exchange for the nectar. But partridge pea seems to be giving it away for free. Or is it? One theory is that these easy-access nectaries entice a specific type of insect that provides some kind of service to benefit the plant, like perhaps preying upon caterpillars that might otherwise eat the leaves. Whenever I sit beside my patch of partridge pea, I usually find an active highway system of small ants running up and down the stems, stopping to drink from the little nectar pots.
I’ve also watched wasps prowling around in the patch of partridge pea. They seem to have a strategy of crawling up and down each stem methodically, and I’m not sure if they’re searching for prey insects or drinking from the nectaries. Maybe both. I watched this grass-carrying wasp moving quickly along several stems, and he did indeed stop very briefly at every nectary. But that could be because he knows that’s where potential prey would be, right? There are so many interesting things to learn or just hypothesize about with this plant!
It’s always hard to try to make a list of my favorite native plants because they’re all amazing for different reasons, but this one would have to be one of my top five. My biggest mistake might have been planting it right beside the patio, because it’s hard to resist stopping to admire it every time I walk past on my way to another area of the garden. It takes me forever to do anything in my yard because every plant provides another magical wonderland for me to escape into. So many bugs, so little time!
I believe one of the first times E.O. Wilson used the phrase “The little things that run the world” was in 1987 as he spoke at the opening of the invertebrate exhibit at the National Zoo in Washington D.C. In part, he said:
“The truth is that we need invertebrates but they don’t need us. If human beings were to disappear tomorrow, the world would go on with little change. Gaia, the totality of life on Earth, would set about healing itself and return to the rich environmental states of a few thousand years ago. But if invertebrates were to disappear, I doubt that the human species could last more than a few months.”E. O. Wilson, May 7, 1987 (full speech here)
In 2022, I look forward to many more blissful hours in the company of these tiny creatures that enable us to live on this planet. I hope you’ll be here to share the joy of discovery with me!