Tag Archives: grassland

A Visual Celebration of Grassland Cicadas

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One of the most unique, beautiful, noisy, and enigmatic insect groups in the prairie is the cicadas.

Hang on, is that good grammar? “Groups is” doesn’t sound right. But the subject isn’t “groups”, it’s “one”, and “one is” works. So that’s ok. But should it be “cicada” or “cicadas”? Is “the cicadas” a group? If so, I’ve got it right.

I guess it’s a great example of what grammar experts often say – “Sometimes, you just have to guess and hope you get it.” It’s nice that grammar experts are so flexible on these things.

Cicadas got a lot of attention last year because there were multiple

Plains dog day cicada (Neotibicen auriferus). I think.

Anyway. I really like cicadas. They’re distinctive and interesting to look at. Their calls are one of the sounds of summer in the prairie and the absence of that backing track would be very noticeable. I also love photographing them – when they’ll let me.

However, with all that said, I’m also frustrated at how little I know about prairie cicadas. Let’s start with identification. I’m pretty sure the cicada above and cicada below are the same species. They look pretty different from each other, but I have it on good authority that they’re both the plains dog day cicada.

You can find plains dog day cicadas every year (unlike the periodical cicadas that emerge only every 13 or 17 years). However, each of them probably lives 4-7 years belowground before coming aboveground and molting into an adult for the quick, noisy remainder of their life.

The tiny little cicada below is a small grass cicada, which narrows it down to a couple different species. It’s less than an inch in length and really easy to miss. My understanding is that there are two similar species that can be very difficult to distinguish based just on photos. If anyone can give a more specific identification on it, please let me know!

Small grass cicada (Cicadettana sp.?)
Small grass cicada (Cicadettana sp.?)

The greenish cicada below might be the same species as the tan ones above, or might be different. I think the most likely choices are Cicadettana calliope and Cicadettana kansa. I’m certainly not going to make any guesses, given what I’ve read about the difficulty in distinguishing between them! I’ll just admire both!

Small grass cicada (Cicadettana sp.?)

The charming little cicada shown below isn’t much bigger than the small grass cicadas, coming in at about 1 1/4 inches in length. It is apparently allopatric, which of course means that it is a species that doesn’t have any range overlap with close relatives.

I say “of course” like I didn’t just look that up. Most of you would have, too, so don’t be smug. I recognized the word as one I used to know, but it’s been a long time since my last evolutionary biology course. Also, it’s called the prairie cicada (Okanagana balli). The Latin is important here since there are several cicadas that are unsurprisingly called “the prairie cicada”.

Okanagana balli

I learned a little about Okanagana balli just the other day from a presentation by Katie Dana at the Illinois Association of Conservation Districts conference. She said that while it’s not one of the periodical cicadas (like the 17-year cicada, for example) it does tend to have big emergences (belowground nymphs maturing into aboveground adults) every 8-9 years.

As I understand it, though, you might see a few every year, so they’re not all on the same schedule. I could also have that wrong, but a quick Google search seems to back that up. I photographed several back in 2019 which likely means I won’t see many (or any) more until 2026 or 2027.

The most spectacular – in my opinion – of the grassland cicadas I’ve seen are the Megatibicen, which come in two species here in Nebraska. In the eastern part of the state, we get Megatibicen dorsatus and further west, we get the nearly identical Megatibicen tremulus. They’re both called “Bush Cicadas”, which is ok, I guess, though I don’t think they’re really tied to bushes or other woody plants. (Please don’t tie insects to bushes.)

As I understand it, experts can tell them apart by looking at the color of some of the wing veins and by their calls. Good for them. What I’m told is that when I see one at the Niobrara Valley Preserve, it’s probably M. tremulus, and when I see one at the Platte River Prairies – or further east – it’s probably M. dorsatus. I’ll stick with that for now.

This big bush cicada is probably Megatibicen tremulus, since it’s at the Niobrara Valley Preserve. Look at that gorgeous color!
Here’s a look at the face of M. tremulus at the Niobrara Valley Preserve. Can you count all five eyes?

Below are two photos of the eastern species of the bush cicadas – Megatibicen dorsatus. Probably. Both photos were taken at our family prairie south of Aurora, Nebraska. The first shows a mating pair with the male on the left and the female on the right. If you look closely, you can see the big plate below the legs of the male, which is absent on the female. Below that plate is the opening to its mostly-hollow abdomen that helps amplify the sound of its calls.

A near-mirror image of bush cicadas (M. dorsatus) except that the left is male and the right is female.
This is another M. dorsatus hanging out at our family prairie.

Here is a video I took of a male bush cicada calling several years ago. It was at the Niobrara Valley Preserve, so I’m assuming it is M. tremulus, but maybe an expert will recognize the song and confirm/refute that for me.

If the video isn’t functional for you, click on the title of this post to open it online so the link will work.

One of the questions I’ve had for a long time is whether cicadas have favorite food plants. Both adults and nymphs drink the liquids from plants and I’d assume there are differences in taste and nutrition between plant species. However, they don’t seem to care much about any differences that might exist.

As nymphs, cicadas attach themselves to plant roots and drink the xylem (liquid) that flows through them. Interestingly, the liquids in plants are split into xylem and phloem, and phloem is the one with a much higher sugar/protein content. For some reason, both adult and nymph cicadas feed on the less nutritious xylem. I don’t understand it, but they’ve made it work for a very long time, I guess.

Katie confirmed what I’d heard from others, which is that there’s no evidence that most/all cicadas have any preferences between plants. They are found on lots of different roots belowground and feed on a wide range of plants aboveground. I suppose there’s a lot of value in being a generalist. As an ecologist, though, I’m always looking for relationships between species and it’s a little disappointing to learn that cicadas will apparently just eat whatever they come across.

An empty exoskeleton of a cicada nymph after the adult emerged from it. You can still see the soil stuck to it because it emerged from underground right before the molt happened.
Here’s a brand new adult bush cicada at the Niobrara Valley Preserve with the exoskeleton it just emerged from in the background.

Cicadas, even the small ones, are relatively thick, armored creatures. They look like they’d be pretty well protected against predators. On the flip side, the noisy calls made by adult males draw attention from more than just female cicadas. I wonder how many females get eaten by predators compared to males?

Birds don’t seem to have any problem crunching through the hard shells of cicadas, and invertebrate predators have found work-arounds as well. I’ve been lucky to come across several examples of cicada predation, some of which I’ve been able to photograph.

If you know how big most crab spiders are, you’ll get a feel for how small this small grass cicada is.
This is one of the biggest robber flies I’ve ever seen, but it was still dwarfed by the big bulky Megatibicen tremulus (probably) it caught.

In both photos above, the predator had to find a chink the cicada’s armor in order to dispatch it. Both the spider and robber fly have similar methods for killing and feeding on prey – they inject chemicals that paralyze and “predigest” the insides of creatures and then suck out the liquefied remains. I don’t know how long it took the crab spider to subdue its cicada because it was over by the time I got there, but I got to watch the robber fly do it and it wasn’t quick. There was a lot of noise and struggling before the fly finally found a spot to work with.

A cicada impaled on a barbed wire fence by a loggerhead shrike at Konza Prairie Biological Station in Kansas.

While I’m no expert on cicada identification or behavior, I can at least appreciate cicadas aesthetically. There’s a lot to enjoy. Their calls and buzzing flight entertain my ears in the late summer and their stocky, shiny, bodies, large clear wings and big eyes make them a joy to see and photograph. When you’re out in the prairie next summer (especially the second half of the summer), be on the alert and you’ll likely find some of the species that hang around your area.

A charming plains dog day cicada face.
Plains dog day cicada at sunrise. Wilson Lake, Kansas

The Show Must Go On

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Almost a decade ago, I wrote about two competing metaphors for prairie restoration. I suggested we view prairie restoration like the reconstruction of a city after a disaster rather than like the restoration of an historic building.  We need to concentrate on the roles and functions of prairie ecosystems rather than how closely a restored patch of prairie resembled what it used to be in the past.

Today, I’m hoping to stimulate conversation about the difficult decisions we face as we try to conserve prairies in the face of rapid climate change.  One conservation planning approach is to focus on conserving the stage, not the actors.  It advocates prioritization of sites with geophysical diversity because those abiotic conditions influence habitat heterogeneity, which supports biodiversity.  The hope is that we might be able to conserve “an abiotically diverse ‘stage’ upon which evolution will play out and support many actors (biodiversity).”

The varied topography and the habitat size and connectivity found in Flint Hills of Kansas makes it a ‘stage’ that can potentially sustain biodiversity – but only with thoughtful, persistent, and adaptive management.

I think the ‘conserve the stage’ approach has merit, but it’s just a first step, especially for prairie conservation.  We don’t just want to save the stage; we want to make sure the show goes on.  Thus, I present to you a long (and potentially ridiculous) metaphor for prairie conservation that builds upon the ‘conserve the stage’ approach.

…

Every actor in a theatrical production plays a role that helps tell a story.  Likewise, every species in a prairie plays a role that contributes to the overall functioning of the ecosystem.  In a healthy and resilient prairie, all the key roles in are filled. 

Fortunately, there is a lot of redundancy built into prairie communities.  We have lots of species that provide pollination, seed dispersal, nutrient cycling, and all the other essential functions that keep prairies going.  We have a big cast, or maybe a big actors’ union.

Today’s prairie ‘show’ already looks different than it did in the past.  Prairie landscapes are fragmented, invasive species have joined the cast, and the climate is changing.  Those and other factors mean that some actors who played key roles in the past are no longer part of the show, at least at some venues.  Other actors remain in the cast but don’t play their roles as effectively as they used to.  Despite those changes, there are still really good versions of the prairie show being presented on various stages, though the versions vary quite a bit from place to place.

To keep the show going, we, as producers and directors, have to be creative and adaptable.  We face really difficult decisions, especially when it comes to actors who aren’t well suited for their roles anymore.  Continuing to direct the show with those actors as the main focus can weaken the performance of others and drag the whole production down. 

Making changes to the cast of a show comes with a lot of risk, however.  We don’t have a lot of experience with that process and we’re likely to make mistakes. Fortunately, in most cases, there are existing cast members that have the potential to adapt their roles and take on new challenges.  With some guidance, those actors will find new ways to collaborate with each other and put on a show that might not be exactly the same as we’re used to but will still have a plot we can follow and enjoy.

More frequent and severe flooding is occurring as a result of climate change. That increased flooding will likely affect which plant and animal species will persist in low-lying prairies like this one. Can we predict those changes and help guide them in ways that don’t lead to reduced biodiversity?

If more drastic actions are needed, we might recognize that some actors are on their way out and start training understudies who can gradually take over roles as needed.  If necessary, we might decide to recruit actors that are playing diminished roles on other stages and bring them in to rejuvenate their careers in a more suitable situation.  Similarly, we might help some of our own long-term stars find new opportunities elsewhere, rather than just watching them slowly fade away. 

In some cases, the world around us might force major a rewriting of the show itself.  We might find ourselves directing a shrubland or woodland production rather than a prairie show.  That doesn’t mean the show will stop or become less important, but it will require a different approach, a significantly altered cast, and a lot of adaptation by all involved.  However, if we stick with the mantra of ‘The Show Must Go On’, we’ll need to figure out how to adjust on the fly and sustain as much biodiversity and ecological function as we can.

…

Ok, I have to break away from this tedious metaphor.  The real point here is that we can’t afford to be so invested in current or past versions of our prairies that we don’t allow them to adapt to changing conditions.  At the risk of sliding back into my metaphor, there are lots of old movies and plays that don’t hold up well today.  Jokes that used to be funny 20 or 30 years ago aren’t funny today.  Old references don’t land with new audiences.  In most cases, the basic stories themselves are still solid – they just need to be adapted for today’s world.  Prairies and their species also exist in a different world than they used to, and that world continues to change (very quickly) around them.

The resilience and function of prairies is highly dependent upon biodiversity, which depends upon habitat size and heterogeneity, along with other factors.  Maintaining high biodiversity in prairies that exist in fragmented landscapes comes with huge challenges, which are compounded by a rapidly changing climate.  Plant and animal communities aren’t the same as they were in the past and they’ll continue to change over the next few decades and beyond.  In fragmented landscapes, unless we take an active role, those alterations will largely take place in isolation, with limited opportunities for species to travel between one prairie fragment and another.  Even in landscapes with large contiguous grasslands, we’ll need to be very thoughtful about how we shepherd those prairie communities through the coming years.

These tent caterpillars probably aren’t causing serious impacts to this patch of wild plum, despite appearances. How will climate change, habitat fragmentation, and increased woody encroachment affect this insect species and its impacts on other species in the future? (This is just a random example – I’m not saying tent caterpillars are going to become a major problem!)

It’s really hard to look at the prairies we know best and imagine them with a different composition of species.  We’re used to measuring stewardship success by our ability to sustain the status quo.  Watching the population of a species diminish in size – or disappear entirely – feels like a major failure.  Most of us have also looked skeptically at any new species that show up in a prairie, worrying about potential negative impacts of that species on the existing community. 

I don’t have a lot of answers to the big questions we face.  I’m certainly not ready to lay out a plan or advocate for a particular approach to managing these changing prairies.  As I did in another recent post, I’m mainly trying to get some conversation going on this topic. 

The best I can do right now is offer a few ideas for discussion.  For example, I think we might be smart to reevaluate the way we look at our objectives for prairie management.  Instead of trying to maintain the current composition of plants and animals, maybe we should focus more on biodiversity and less on which particular species are present or abundant within those communities.  (That doesn’t mean we welcome invasive species, by the way.  Any species – plant, animal, or otherwise – that acts to reduce biodiversity is still a problem.)  

I also think we need more serious conversation about when to resist ‘state changes’ like the transition from grassland to shrubland and when to facilitate those transformations, while trying to preserve as much biodiversity and productivity as we can.  Again, I have little to offer in terms of specifics, but it seems clear that we’re not going to be able to stave off those state changes forever in at least some places.  Let’s start thinking about contingencies instead of just waiting for those sites to collapse.

There’s a lot of woody encroachment in this prairie. The number of trees in the surrounding landscape and a changing climate are both spurring that invasion. At what point does the fight against this kind of encroachment become fruitless? What do we do then?

Finally, it’s never been more important to find opportunities to enlarge and reconnect prairie fragments through prairie restoration.  The chances are slim that a small, isolated prairie fragment is going to adapt well to a rapidly changing world.  Growing the size of those fragments by restoring adjacent patches should be a top priority.  Can we find new approaches for creating those restoration opportunities in strategic locations? As we do that restoration work, we should also continue to test and discuss seed sourcing strategies, including the regional admixture approach, to see if we can further bolster the adaptive capacity of those small sites.

We’ll be figuring this out as we go, and we’ll surely screw some things up, but we can’t afford to just continue reacting.  At the very least, we need to be thinking ahead about the changes that are taking place and how those will affect prairies.  In some cases, we should probably be ‘acting ahead’ to guide state transitions, migration of species, or simply changes in species composition within individual prairie sites. 

What we can’t afford to do is live in the past.  We’re hurtling into the future whether we like it or not.  Let’s make sure we bring prairies along with us.