Hubbard Fellowship Blog: Ant Swarm (and Lunch)

This post was written by Evan Barrientos, one of our Hubbard Fellows.  Evan is a talented writer and photographer and I encourage you to check out his personal blog. If you would like to see more of his photographs, you can follow him on Facebook.

Don’t worry, I didn’t eat a swarm of ants. But late last September while I was harvesting seeds I did notice enormous clouds of small flying insects swarming above the prairie. The swarms were constantly shifting shape but they were roughly the size of small cars slowly floating across the land. Intrigued, and slightly mesmerized, I walked directly beneath one.

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Closer up I could see that the mystery insects had very narrow waists, which suggested that they might be in the order Hymenoptera (ants, bees, and wasps). Their brown color made me think they might be flying ants.

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Then I began to notice several individuals crawling in the grass below the swarm. Some were caught in spider silk; not complete webs, but loose strands of silk. Looking around, I realized that there were dozens of silk strands scattered among the grasstops of the prairie. As I knelt to photograph one ensnared ant, I saw a small jumping spider stalking another. The spider crept up, grabbed the ant, and carried him away for lunch. Were these silk strands deliberate traps set by the jumping spiders or were they just remnants of ballooning juvenile spiders that happened to catch the ants? I still don’t know.

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Later, I sent the photo below to James Trager, an ant expert, and learned that these were in fact flying ants, Myrmica americana to be specific. It still AMAZES me that there are people who can identify insect species  from just one photo!  He explained that there are actually three different species that currently are all called M. americana because two have not been officially named yet. The unnamed species I encountered is very common, which shows how much we still have to learn about even the insects in our backyards.

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Not only did Trager know the species’ name, but also the explanation for their hypnotic swarming behavior. When it’s time for M. americana to reproduce,  winged males swarm together, forming what’s called a lek.  Reproductive females are drawn to the spectacle and watch from the leaves below. Males will periodically descend from the swarm to crawl around in search of females to mate with (or get snagged by spiders). If a male is lucky enough to avoid the predators below, he may find a female to copulate with. But the challenge doesn’t end there. Once a male begins copulating, dozens of other males will often swoop in and try to do the same, forming what’s called a “mating ball.” After the whole fiesta has ended, the female pulls out her wings (so that she can convert her wing muscle into food to feed her offspring via glandular secretions) and walks away in search of a place to start her own colony.

Finally, here’s a video of the lek, first at full speed, then in half-speed slow motion.

Photo of the Week – December 4, 2015

We had a winter storm pass through our area at the tail end of the Thanksgiving weekend.  After a light coating of ice, we got a couple inches of fluffy snow.  Monday was a gloomy overcast day – too dark to inspire me to venture out with my camera.  However, Tuesday morning began with a beautiful sunrise and calm winds.  A fantastic opportunity for winter prairie photography.   Unfortunately, I had to enjoy the light from the interstate as I drove to a meeting.  Wednesday was another great sunrise and morning of light, but I was on the road again – heading to a different meeting.  Yesterday, most of the snow melted and, just like that, the first snow of the year was gone.  Not a single photograph taken…

So, instead of posting a beautiful photo of fluffy snow on the prairie today, I’m reaching back to a photo from August.

Stiff sunflower (Helianthus pauciflorus) Lincoln Creek Prairie, Aurora, Nebraska.

Stiff sunflower (Helianthus pauciflorus) Lincoln Creek Prairie, Aurora, Nebraska.  Click on the image to see a larger version – and maybe the hidden visitor on it.

I like this photo of a stiff sunflower for several reasons, including the interesting shapes of the ray flowers (“petals”) that are not yet fully extended.  However, I also like the photo because there is a hidden visitor on the flower that I didn’t see until well after I took the photo.  Can you see it?

Here is a cropped version of the image to give you a better look.

Stiff sunflower (Helianthus pauciflorus) Lincoln Creek Prairie, Aurora, Nebraska.

Can you see the tiny larva feeding on pollen?

I don’t know what this little larva will grow into, but it appears to be feeding on pollen and stringing lines of silk between anthers as it moves.  I featured a similar larva in an earlier post that showed a sunflower which had been “sewed shut” by silk – probably as a protective measure to allow the larva to feed on the flower under cover.  I wonder if this larva will follow the same procedure as it gets bigger and can’t hide as easily out in the open.

Interestingly, the photos from that earlier post featuring the “seamstress larva” were taken on the same day as the photo in this post.  In fact, I took the photo of the tiny larva just a few minutes after photographing the sewed-up flower.  You’d think I’d have been on the lookout for larvae on sunflowers, but I still missed it, even through my macro lens.  Then, I missed it again as I worked up the photo later, even as I was looking closely at it on the computer to adjust sharpness, etc.  I guess that’s a testament to the effectiveness of the hiding strategy of this little larva!

I hope its camouflage allowed the little larva to grow up, pupate, and have lots of offspring to carry on its strategy.  I bet it did.