Sunday, November 9, 2014

An Unfortunate Romance





Some relationships are doomed from the start.  I’ve been watching one such hopeless attraction in the largest of my singing insect terrariums.


It’s between a male Black-horned Tree Cricket and a male Short-winged Meadow Katydid.  


 

They’ve been pursuing their passion for three days now, but they’re not even in the same family.  The closest thing they have in common is membership in the suborder Ensifera.   

That does not deter them.


This terrarium is large a has lots of goldenrod seed heads, small white asters, timothy seed heads, a little smartweed arching up under the overhead screen…


…and two male Black-horned Tree Crickets, one female Short-winged Meadow Katydid, and one male Short-winged Meadow Katydid who has no interest in the female.  Maybe she has no interest in him.  

Here's the male clinging to the side of the terrarium as if he were a treefrog, and the lovely female watching me from an oak leaf.





 All I can confirm is that he seems to be interested in one of the two Black-horned Tree Crickets and that this particular cricket actively courts the katydid.


The first thing I noticed was this song:




When I hear Black-horned Tree Crickets singing these short phrases out in the meadow, there is a female very close by.   The more common song is a long, continuous trill.  It’s demonstrated here by the other male Black-horned Tree Cricket in the terrarium. 






So why was the first male singing what I think of as a courtship song?   Here’s what I saw.

 

This is crazy. The mating positions of tree crickets and meadow katydids are very different.  What were they going to do?


Each tried to position the other in the appropriate position.  The male Short-winged Meadow Katydid arched his abdomen toward the Black-horned Tree Cricket.   


It appeared that he was trying to maneuver his cerci into position to lock with a female katydid.  Obviously, this wasn’t going to happen.




And the Black-horned Tree Cricket?  He tried to position the katydid behind his wings, where a female tree cricket would dine on secretions from his metanotal gland during mating. 



Having seen what the meadow katydids were doing to the lettuce in the terrarium, this is not an individual that a tree cricket should have behind his wings. 




I thought the Black-horned Tree Cricket was initiating all of this, as his courtship song is what I heard.  Yet what I saw was the Short-winged Meadow Katydid just as engaged as the tree cricket.


When I got my microphone close enough to record the Black-horned, I finally heard it. Listen:


Did you hear the very high and (to us) soft song of the Short-winged Meadow Katydid when the tree cricket stopped singing?  They were both singing!


Here’s the Short-winged singing when the Black-horned paused for a short while:




I have watched the Black-horned Tree Cricket search out and approach the Short-winged Meadow Katydid both on the screen and down in the leaves in the terrarium.  The screen “ceiling” is their common meeting place, though.   



Once the tree cricket finds his katydid, they touch antennae and the tree cricket starts singing.  Then the maneuvering begins again.  Eventually they give up for a while, but there’s always tomorrow.
 



Have you seen this behavior before?  I’d love to hear your thoughts and observations.  Did the first frost make them crazy or desperate, or did they both come from the shallow end of the gene pool?








2 comments:

  1. Fascinating. I can't imagine the hours of observation that would be needed to find something like this in the field. It is simply amazing that you collected two individuals that would exhibit this behavior. Your frosted brain hypothesis is interesting, but how on earth could it be proved. Think of the hours and thousands of individuals it would require... It is great that you have such a keen eye and noticed what was going on here.

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  2. I found a male O. forbesi this summer (outdoors) that kept trying to entice a wasp to mate. The wasp was not interested, and kept moving away -- but the tree cricket kept following it.

    Your photos and recordings are awesome.

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