Tuesday, July 2, 2013

The first singing katydid of the season

There’s a new sound in the meadows now – it sounds like an electrical buzz in the tall grasses or damp sedge meadows.  You look and look, and don’t see where it’s coming from... but  it’s right down there somewhere!

Wait a minute….what's clinging to the stems?

Roesel’s Katydids – the first katydid to sing in our area.  (And that picture of the tall grasses has three Roesel’s Katydid nymphs staring right at you from their perches.)

Now I will be the first to admit that it’s not the most delicate, melodic song, but it announces the beginning of the katydid concert.  And they are very pretty little insects with an interesting story!

This species is an accidental European introduction, having reached our continent around 1950.  It landed in Montreal and spread throughout the Northeast; until recently, the range map for this species only showed it in that area…and a curiously isolated population in Illinois.

That wasn’t really the case, however.  They are all over NE Ohio and are actually quite common.  I’ve recorded and photographed them in Cuyahoga, Geauga, Lake, and Summit counties, and they are certainly in other nearby counties as well.  Illinois naturalist Carl Strang (Forest Preserve District of DuPage County in the Chicago area) has now tracked these katydids from his area back to our NE Ohio katydids, so we now know that these populations are connected. (You can follow his singing insect research in his blog, “Nature Inquiries.”  There is a link in my sidebar)

Roesel’s Katydid – Roeseliana roeselii - is a type of katydid called a “shieldback.”  In the pictures below, you can see the “shield” behind its head.   

 We have native shieldbacks as well, but they are not as colorful and are less likely to be seen during the day.  In fact, I see our native shieldbacks far less often.   This is not because of competition from Roesel’s, however.  Roesel’s Katydids are a late spring/early summer insect that does not seem to compete with our native katydids, and their time onstage is ending when our first native katydids begin to sing.  The recording below is a Roesel’s Katydid singing with Spring Field Crickets at Springfield Bog in southeastern Summit County.

So how did they get here?  Roesel’s Katydids have short wings that barely seem long enough to create songs, let alone fly anywhere.   

But although most of them do indeed have short wings, there are also long-winged males and females that are capable of flying into new areas when the population gets a little crowded.  Here is an example of a long-winged female. 

Even short wings can generate those high-pitched songs.  One wing has a file and the other a scraper, and they rub one wing against the other at an incomprehensible rate of speed.  Their wings are a blur when they sing.  

The most prominent frequencies in their buzzy, crackling songs is between 12 -19 kHz- higher than many older adults can hear – and my WAV file recordings show frequencies well about 20kHz (the threshold of human hearing.   The mp3s I use for this blog actually cut off the top frequencies of the songs!

In my opinion, the nymphs of this species are adorably cute.   

Actually, I think the adults are quite attractive as well.  Katydids are gentle, harmless insects and will often be quite willing to sit on your hand.   

They really have no defense other than escape and camouflage, but they blend astonishingly well with the plants in which they live.   They eat plants – and they certainly seem to like grasses. 

Good luck searching for these little singers.  Our earliest native katydids will start singing any time now, so you only have a few more weeks to find Roesel’s Katydids!


  1. Hi, Lisa,
    Thanks for the mention. I should add that botanist Scott Namestnik has been my collaborator in the distributional work on Roesel's in Indiana and Michigan. Alas, I find that I hear this species less well each year as my aging ears cut off more and more of the top frequencies. One question you can help me with is how late in the day this species sings. Here in northeast Illinois they begin mid-morning, sometimes with a distorted warm-up earlier, but I can't say for sure how late they go. Early afternoon, at least, but I would like to pin it down better.

  2. I hear them from mid-morning throughout the afternoon. I don't recall actually hearing them after dark, though they are still active after sunset. A warm, sunny day is an excellent time to listen for them. We have not had many of those in NE Ohio this year, but maybe soon...