Wednesday, November 26, 2014

Katydids in the Kitchen





In my last post, I wrote about all the ground crickets currently singing in my studio and the Fall Field Cricket who sang for quite a while in the kitchen.  We also set up a large terrarium with a male and female Short-winged Meadow Katydid and two Black-horned Tree Crickets. They, too, had come home with me before the major cold front on November 11th.  We certainly have learned a lot from them! I’m going to focus on the katydids, but I’d like to start with the Black-horned Tree Crickets.  That's probably appropriate, as you certainly would have heard their songs above all the other crickets and katydids.


We’ve never had them here in the house before.  The afternoon before Superstorm Sandy in 2012, I brought home a Four-spotted Tree Cricket that lived - and sang – into the first part of December.  That was the only tree cricket of any species that had been in residence here.  I’d wondered how similar or different a Black-horned would be.

There was no mistaking that song for a Four-spotted Tree Cricket.   





They are very loud and their song sounds quite concentrated or dense, as they make more wings strokes per second that the Four-spotted Tree Crickets that typically share their meadows.  Here's a recording of a Four-spotted followed by a Black-horned; they were on adjacent plants, so they were singing at the same temperature.  You may be able to hear the different quality of the Black-horned Tree Cricket. (Just note that the recording was made at 80 degrees - certainly a higher temperature than that of our house.)



From a bit of a distance, the Black-horned song sounded rather like a whistling teakettle, which was not inappropriate coming from a terrarium in the kitchen. The song has a distinctive pitch that I can immediately play on the piano, and that pitch is actually significantly lower than the lighter songs of the ground crickets.  The song's pitch can be lower or higher out in the field depending on the temperature, but it obviously doesn't fluctuate as much in the house.


The song doesn’t begin as smoothly as I thought; it seems to take a second or two to get those wings up to full speed.  Once he’s singing, though, he can continue for quite a while without stopping.  Short phrases of song seem indicate courtship behavior, and I heard this regularly when one of the Black-horned Tree Crickets repeatedly courted the male Short-winged Meadow Katydid.  You can listen and read about that ill-conceived romance here.


The Four-spotted Tree Cricket was very fond of timothy seed heads in 2012, as are many crickets and katydids, and I placed these in the terrarium both for food and to provide perches from which the Black-horned Tree Crickets could sing.  They welcomed both uses.  The Short-winged Meadow Katydids, too, seem very pleased with the timothy.





The Short-winged Meadow Katydids were more perplexing than the Black-horned Tree Crickets.  They promptly climbed up to the terrarium’s screen lid and stayed there.  Didn’t they like the plants I had more them, and all those stems with clusters of timothy, aster, and goldenrod seeds?  Why did they keep hanging upside down like that?  Did they hate it in there?


I’d tried once before to keep a Short-winged Meadow Katydid because I was hoping to listen to and record his soft, high-frequency song.  He did the same thing.  He just stayed on the screen, day after day, so I assumed he hated his life.  I finally took him back to exactly the clump of sedges where I’d found him.

But these katydids couldn’t go back.  They would immediately perish. Fortunately, they also climbed on the plant stems just below the screen.  



I finally realized that they just wanted to be up there.  They climb a lot, including right up the sides of the glass walls.  How do they adhere to such a smooth surface?  Apparently, it’s not a problem for them at all.   Short-winged Meadow Katydids will climb up to the top of various grasses in the meadows at night when the birds aren’t out – even big bluestem.  They must be climbers by nature.


I really did wish the male would sing, though.  It’s so hard to hear them out in the field.  I thought for sure that I’d hear him very well in the kitchen, but no.


Except he actually was – we just didn’t hear him!  When I recorded the Black-horned Tree Cricket that was singing his courtship song to the katydid, my microphone revealed that the katydid, too, was singing!   Once we started listening carefully, we could hear him, but only if we were quite close.  I've edited this recording of him and increased the sound level enough that I think most of you will be able to hear him.  



If you read the story of how the katydid and the cricket tried to find a mutually agreeable position for mating, you might have wondered – as did I – why the katydid wasn’t trying to mate with the female Short-winged Meadow Katydid.  Had she recently mated and oviposited?  


But then on November 11th, I saw this when I went from the dining room to the kitchen!  



It certainly looked like the ovipositing (egg-laying) I’ve observed with meadow katydids in the field.  She seemed to focus on one spot on the timothy stem, then subsequently move to a different spot.  The stem seems too narrow, but the behavior looked right…





…and then I saw him right nearby on another stem, singing, then watching, then singing.  This is exactly the behavior I’ve observed in Black-sided Meadow Katydids and Long-tailed Meadow Katydids.  Both of these species, like the Short-winged meadow Katydid, are members of the genus Conocephalus.


I don't know that she was actually ovipositing; a substantial stem seems more appropriate, though I'm not sure.  I'm going to keep the contents of this terrarium out in the garage so it gets cold enough to simulate winter, and I'll keep the soil damp when temperatures are above freezing.  If I find any nymphs next year, I'll report back to  you.

 
I observed ovipositing behavior with a female Striped Ground Cricket a couple of weeks earlier, but there was no male Striped in her terrarium.  Why?

 
Because she despised him.  From the moment I scooped her and the male up from a path into my plastic jar, she tried to get away from him.  I thought she'd be OK once they were in a terrarium together, but she still tried to escape from his advances.  I eventually found her hopping around the floor of my studio!  I put her in a larger terrarium with the Spotted Ground Crickets, and she's been fine ever since.


She tried the soil in a few places before plunging her ovipositor into the ground in a couple of different places.  When she was finished, I watched her scoop dirt back over where she'd deposited her eggs, using her blade-like ovipositor as a little trowel!

So I know that when I observed the behavior in the photo above, there wasn't a male involved (unless a Spotted Ground Cricket male decided to get ambitious and go for a much larger female!)  However, I've just learned from Wil Hershberger (see his outstanding work at the Songs of Insects) that female meadow katydids can lay eggs all season after mating just once, and female crickets can store sperm to fertilize eggs for weeks.  Maybe that's why she wanted to get away from that male and his unwelcome interest!


The Black-horned Tree Cricket continued to sing to the Short-winged male for a few more days, but his songs became softer and weaker.  He was really just old, though it sounded like he died of a broken heart.  


The other Black-horned Tree Cricket continued singing through November 17 and I watched him feeding on a piece of lettuce on the 18th.  When I got home from work the next day, he was motionless on the soil below the lettuce. I gently picked him up to see if he was still alive, and his front legs weakly grasped my finger to hold on as if my finger were a plant stem.

His antennae were still erect.  I held him for a little while and observed him up close in all his beauty, then gently placed him on a ground-level leaf .  He slipped away.  I really miss his resonant song, which I could even hear upstairs in the bedroom at night.


The katydids are still here as of November 26th, though the male has lost one of his back legs. 


As you can see, he’s still hanging upside-down on the screen cover of the terrarium.  She still hangs on the side of the glass wall when she isn't climbing on the seeds and stems I've provided.  

It’s been fascinating to observe their behavior and a gift to hear his soft song in the kitchen.  This species is absolutely abundant in NE Ohio; they are by far the most common of our meadow katydids.  Only now do I feel like I've really gotten to know them.  I'll close with a longer recording of him singing at night when the neighborhood was quiet, our large cat Tatyana was asleep, and our little gray Dmitri was only playing on the terrariums just a little.  Turn it up a little as needed, and enjoy his peaceful song.





2 comments:

  1. What a wonderful and beautiful testament to the beauty, both sight and sound, of these tiny creatures. Meadow katydid females need only mate once and can then lay eggs all season long. Crickets are somewhat similar in that females can store sperm for long periods of time and fertilize eggs for weeks after mating. So, the eggs you were observing being laid might very well be fertile.

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    Replies
    1. That is fascinating, Wil - thank you! Now I'll definitely be keeping a couple of these terrariums in the garage during the winter to see what happens.

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