Katydids are a diverse group of species – about 243 different species reside in the U.S. and Canada. We have about the same number of katydid species as we do grasshopper species in our Platte River Prairies, but grasshoppers tend to grab a lot more attention. In fact, katydids are often called “long-horned grasshoppers”, though they’re actually much more closely related to crickets than grasshoppers. Katydids are often difficult to see because of their camouflaged appearance, but it’s impossible not to hear the distinctive songs they make by rubbing their front legs together – especially in late summer.
Katydid on false sunflower. Sarpy County, Nebraska.
In the above photo, you can see the tympana on the katydid’s front leg – right below its “elbow”. The tympana is the hearing organ katydids and crickets use to hear the songs of others of their kind.
Telling grasshoppers and katydids apart is usually as easy as looking at the antennae (see below). Grasshoppers have short antennae – much less than the length of their bodies. Katydids have very long antennae that usually exceed their body length.
A grasshopper showing off its short antennae.
A katydid nymph (hence the short wings) with its long antennae - long enough I didn't capture their entire length in the photo.
The sound production of katydids and crickets is made by rubbing a file on one wing base across a scraper on the other. The wing membranes themselves, and the position in which they are held during stridulation, amplify the sound, sometimes to a nearly deafening level. The katydid in the first picture is a Scudderia (bush katydid), while the one at the bottom is an immature female (note ovipositor) of an Amblycorypha (round-headed bush katydid). Both make relatively soft series of prolongated click sounds, of such high frequency as to be inaudible to many folks.
Grasshoppers, on the other hand, rub the femora of the hind legs against the wings to make their more subtle, rustling sounds. Exception, the so-called “cracklers” which produce a sound reminiscent of cards in the bicycle spokes while in flight. I’ve never read a good explanation of how they do that.
Gee, it’s great to have you following this blog James… All I have to do is lob one to you and you hit it right out of the park! Thanks for the IDs and the great explanation of katydid stridulation.
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