Prairies are an endless source of fascinating stories. As I’ve explored prairies with my camera this summer, I’ve encountered a lot of those stories – some of which I already knew, some I learned for the first time, and some I can only guess at. Here are a few examples.

The first came at our Niobrara Valley Preserve back in May. I stopped to photograph a large bison wallow that had held water but was now drying up. There was a bunch of little barley (Hordeum pusillum) around the edge and I liked the way the light was passing through the flowers.

As often happens, once I was down on the ground and looking closely, something else caught my eye. There were several plants that had flies with white abdomens perched near their tops. When I got closer, it was obvious the flies were dead. What’s with that??

I switched to my macro lens and immediately saw that the white abdomens weren’t normal. Instead of flies with white abdomens, these were flies that appeared to have something wrapped around their abdomens.

Dead insects clinging to tops of plants often means a fungal infection, so I figured that might be at least part of the explanation. Later investigation online confirmed that.

I’m pretty sure these flies were infected by a fungus in the genus Entomopthera – there are different fungus species within that genus, and each affect different groups of flies. If a fly contacts a fungal spore, the fungus grows into the fly’s body, eventually reaching the brain. That causes something called “summit disease”, in which a fungus drives its host to climb up high and attach itself to a plant by its mouthparts (reinforced by fungal secretions) just before it dies.

In this case, the fungus also breaks through the abdomen and creates the diaper-like structure I’d noticed. If the weather is humid enough, the fungus can produce spores that are carried off by the breeze where some might hit another fly. The elevated position of the dead fly helps the spores fly further. However, male flies are also attracted to female flies that died from the infection, and as they investigate those females, they can pick up spores directly. Later, those infected males can spread spores to other (living) female flies, perpetuating the cycle.

Yowza.

Continuing the morbid tone of this post a little further, I found some more death at Lincoln Creek Prairie last month. I was photographing pools of water captured in the leaves of cup plant (Silphium perfoliatum). The plants are named for the way their leaves wrap fully around their stems and trap water.

Many of the cup plants had dead insects floating in the water they held. I’ve seen this before and have wondered whether the plant gains anything from the death it causes in this way. I’ve not read or found anything that says the plant benefits, but I’d love to know if others have information on this. As far as I can tell, the dead insects are just a morbidly fascinating example of collateral damage. I don’t even know if the plant benefits from the water it catches – maybe that’s extraneous, too?

On a more cheerful front, I was able to find and photograph some yucca moths down in Kansas at the end of May. Kim was running an ultramarathon and I was wandering around a fairly low-diversity old pasture. Amongst the mostly invasive grass-dominated vegetation, I came across a little cluster of three yucca plants that were blooming. Given the isolation of those plants from others, I wondered if the obligate pollinator – the yucca moth – would be present. It was!

I wrote a post long ago about the story of the yucca and its specialist pollinator. It’s an often-used example of mutualism, in which two species each benefit from their interaction. The moth helps the yucca by pollinating it (it’s apparently the only insect that pollinates yucca plants). However, when the moth deposits pollen in the flower’s stigma (the opening that leads to the ovary), it also lays eggs in the same place. When they hatch, the moth larvae feed on the developing yucca seeds, which provide enough nutrition to let the larvae grow and develop.

That’s all well and good, but if the yucca moth lays too many eggs, the larvae will eat all the seeds, leaving the yucca without any potential offspring. There are two factors that help prevent that. First, the moth leaves a scent behind when she leaves eggs, which seems to either prevent egg laying by later moth visitors, or at least reduce the number they lay.

The second factor is the big mystery of this relationship and, as far as I know, has yet to be solved. Yucca plants can apparently sense (?) if enough eggs have been laid that it’s likely none of its seeds will survive. When that happens, the plant will abort that flower, dropping it to the ground and cutting its losses. I’d love to hear an explanation for how the plant makes that decision!

During the same Kansas race, I noticed a bunch of wolf spiders running around in the mowed grass near our campsite. Between Kim’s laps around the pasture, I managed to get some decent spider photos. After I’d photographed several, I was walking back to camp when I noticed one more. It caught my eye because I could just barely see something green below its eyes. My first thought was that I was seeing green fangs, but why would this one have different fangs than all the others I’d been looking at?

I slowly dropped into the prone position and edged my way close enough to focus my macro lens on the spider and realize what I’d seen. It was the head of tiny katydid nymph! Only later, when I got the photos on my larger computer screen, did I see that the entire katydid was there. For a while, I thought I’d seen a wolf spider carrying the head of its victim around like a trophy! Nope, it was just feeding on the katydid like a perfectly normal spider.

Last week, I was back up at the Niobrara Valley Preserve. While walking around in the evening, I noticed something odd on the flower of Scribner’s panicum (Panicum oligosanthes). I didn’t recognize the caterpillar, but later found out from Bugguide.com that it is the wheat head army worm (Dargida diffusa), which feeds on grasses. I didn’t see this one eating anything. It just hung out on the grass flower, but it seems reasonable to expect it might have eaten something after I left. Either way, it was a new species to me, and fun to learn about.

In mid June, I spent a couple days out in the Nebraska panhandle, including at The Nature Conservancy’s Cherry Ranch. I ended up tent camping so I could take advantage of the evening and morning light for photography. I set up my tent in mid-afternoon and didn’t notice the little evening primrose plant just a few feet away. Later in the evening, though, the plant lived up to its name and opened its flowers. After the sun went down, I set up my camera to get a photo of the blossoms in the growing darkness. I placed my camera on a bunched up old towel to get it into the right position for the shot and then used a remote trigger and long exposure to make the photo.

A big highlight of western Nebraska summers is the abundance of common nighthawks. I saw lots of them at Cherry Ranch and, later, at the Niobrara Valley Preserve. While at Cherry Ranch, I photographed several roosting nighthawks, either on fence posts or just sitting on flat rocks.

During my most recent trip to the Niobrara Valley Preserve, I was taking an evening hike north of the river and flushed a nighthawk off the ground toward the top of the rocky slope. It flew awkwardly, which led me to believe it might have gotten up off a nest. I was sort of right.

I found two well-camouflaged eggs sitting directly on the ground. I’m not sure it counts as a nest when a bird doesn’t build any kind of structure to place its eggs in. To be fair, a nest in this context would probably have been more obvious than the eggs by themselves. The recently burned (last December) site had lots of bare ground, and those eggs blended perfectly into that background.

Our family prairie is having a good year. The drought has finally eased and everything is green and lush. On one of my most recent visits, I found a crab spider feeding on a true bug of some kind. That’s not particularly noteworthy – I see crab spiders frequently, and they often have captured prey. In fact, just last weekend, I saw three crab spiders with food within the span of about 10 minutes. One of them had a little grass cicada, which seemed pretty ambitious.

What made this particular spider interesting, though, was that as I photographed it, several little flies showed up. They seemed to be there on purpose, and aggressively present, including sitting on the captured bug itself. This isn’t the first time I’ve seen this behavior, but I haven’t yet figured out what’s going on. Are the flies laying eggs on the insect corpse? If so, that’s a pretty great strategy – just hang around a crab spider until it catches and immobilizes an insect and then lay eggs that can later hatch and feed on the remains.

I’d sure love to know if that’s really what’s happening!

The most fun recent sighting I’ve had came thanks to Claire Morrical, one of this year’s Hubbard Fellows. We were exploring the Niobrara Valley Preserve and she spotted some sunflower tortoise beetle larvae feeding on Jerusalem artichoke leaves (a perennial sunflower). I’ve written briefly about these creatures before, including their incredible strategy of waving poop-tipped tails above themselves to ward off predators.

As I was setting up to photograph the larvae, Claire called out again. “Hey,” she said, “I don’t want to interrupt you, but when you get done, come look at this amazing beetle I found over here!”

I quickly photographed the larvae and then walked the short distance to where Claire was admiring a shiny green/gold beetle sitting on another Jerusalem artichoke leaf. Unbelievably, it was an adult sunflower tortoise beetle! I’ve looked for one of these ever since first seeing the larvae a couple years ago, but hadn’t ever found one. Claire found one within seconds of her first larvae sighting! Amazing.

Sunflower tortoise beetles are well-named. This one was sitting flush to the leaf when I first saw it, hiding all its legs and body beneath its hard shell. It’s easy to imagine ants or other predators fruitlessly trying and failing to get past that defense. As I watched, the beetle eventually lifted up slightly, exposing its fuzzy little feet. Wow!

It’s hard to sit inside this time of year, knowing how many stories are playing out in the prairie RIGHT NOW. My square meter project has given me a lot of opportunities to watch lots of stories within a tiny area. Knowing how much happens at that scale makes it almost impossible to imagine what’s all going on across acres and acres of prairie…

Hey – why are you sitting there looking at a screen? Go find some stories!