Field Crickets
Here’s one that probably everybody in North America has at least heard, if not seen: field crickets. I recorded this sound clip on June 17, which was when the spring field crickets (Gryllus veletis) started singing[1].
There’s actually two very similar species of field crickets around here, they look the same, sound the same, and pretty much act the same. The only observable difference is that the spring field crickets like these overwinter as nearly-mature nymphs and sing in the late spring, while the fall field crickets (Gryllus pennsylvanicus) overwinter as eggs and don’t sing until fall.
Back in April, Sam had caught for me a spring field cricket nymph. You can tell it is immature, because it doesn’t have any substantial wings yet, but it had clearly overwintered as a nymph in order to be this big so early in the spring.
In contrast, last year in late May, S_ caught this much smaller cricket nymph in the house. Since it was so small so late in the spring, it had evidently overwintered as an egg and just hatched out recently. It is therefore a Fall Field Cricket, and wouldn’t be mature until the end of summer.
On June 25, I happened to find a whole clutch of the spring field crickets in the yard[2], and caught both a male and a female.
There are a couple of obvious differences between the males and the females. First of all, the males are the ones who do the singing, by rubbing their wings together. They therefore have larger, heavily-veined wings, with the sound-making apparatus supported by the veins.
The females, on the other hand, have smaller, simpler wings without the heavy veining structure.
Of course, the most immediately obvious difference between the males and the females is that the females have a long, swordlike ovipositor for laying eggs, while the males do not.
There are two other long projections on the back of the abdomen, these are the “cerci”, and the males have them too. If you look closely at the cerci, there are fine hairs all over their surfaces. These hairs are socketed so that they can only move in particular directions when they are hit by a puff of wind. This gives the cricket a pair of very sensitive and highly directional detectors for bursts of wind caused by, say, a lunging spider, a toad flicking out its tongue, a bird swooping down, or a small child trying to snatch it. This is how crickets know to jump when something tries to grab them [3].
Field crickets are also astoundingly slippery, making them hard to hold onto, and like other crickets and grasshoppers they have spines on their hind legs that can make them unpleasant to eat. This is important, because they are otherwise extremely succulent insects, quite large and tasty-looking. Without some defense, they are sure to be somebody’s lunch [4]. They make excellent fish bait, and are usually easy to find by flipping over rocks, even when it is too dry out to find worms.
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[1] The voice asking what I was doing about halfway through is Sam, my oldest daughter. She was curious why I seemed to be taking a movie of a blank, grass-covered hillside.
[2] We have a fold-up cloth-covered stroller that had been left on the back porch overnight. I picked it up and unfolded it, and it was full of crickets.
[3] Cockroaches, and a lot of other insecs, also have these structures that they use to sense danger. In the “Spider-Man” comics, Peter Parker’s “spider sense” is actually a lot more like the air-pulse sensing of a cockroach or a cricket than anything a spider can do, but I suppose “The Amazing Cricket-Man” wouldn’t make as snappy of a comic book title.
[4] When I finished photographing these, in fact, they went to feed Sam’s tarantula. The tarantula is pretty lackadasical about her eating habits, and ignored the crickets for some time. The male started chirping to court the female within about 30 minutes or so, and we were able to watch how he did it: he lifted up the wings to about a 30 degree angle to his body, and moved them rapidly from side to side, with their inner edges rubbing over each other to produce the chirp. It looked like the rest of the wing surfaces acted as sounding boards to amplify the sound. He kept this up most of the night, but at some point that morning the tarantula evidently decided she’d had enough, and ate him[5]. Everybody’s a critic.
[5] Update: the tarantula really, really loves these. Once she got a taste of the first one, the second one only lasted a couple of hours, and the two that we’ve fed her since then have both been pounced on in less than a minute. This is in contrast to the crickets from the pet shop that were the only things that she had been fed previously, and which she used to ignore for hours or days before finally rousing the interest to eat one. I guess free-range crickets are a lot tastier than the store-bought kind. Isn’t that usually the way these things work?
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I like the sound recording. That’s something I keep meaning to have a go at.
I should probably mention how I made the sound recording. I wasn’t sure how to do it at first, and was thinking that I’d need to buy some sort of microphone and sound recorder. But then, S_ very intelligently pointed out that my camera can shoot movie clips with sound, so I already *had* a microphone and sound recorder. All I needed was a program to strip out the soundtrack from the video, and voila! A friend recommended using Virtualdub for this, as it can painlessly strip out the audio from the *.avi files that my camera generates- just tell it to save the file as a *.wav file, and it’s done (Thanks, John!). And, in keeping with the subtheme of this site of trying to do things without spending any actual cash, it’s free. So, I was able to get a reasonable sound recording without buying anything at all!
Thanks for posting the additional information on how you made your recording.
What type of camera did you use to capture those impressive images?
I used a Canon Powershot A95, souped up with a macro lens that I made by reversing the lens from my old Olympus OM-2 camera. I’ve got a lengthier desciption of my setup on this page
hey quick question … will stone centipedes eat thees thanks again ,jack
Jack: The stone centipedes will probably only eat crickets that are a bit smaller than themselves. The centipedes we have in Michigan could probably manage cricket nymphs, but aren’t big enough to deal with the adults.