by Carl Strang
Today’s chapter in the Sound Ideas winter series is a recording from the evening of September 4 last year. I made it in the Miller Woods portion of the Indiana Dunes National Lakeshore. Three very different singing insects can be heard distinctly throughout:
The principal target of this recording produced the annoying, continuous buzzing sound. If you had been there, you would have remarked at how loud this insect was. It was a robust conehead.
This katydid has a sibling species, creatively named the false robust conehead (Neoconocephalus bivocatus). I haven’t documented bivocatus in the Chicago region, but there are a couple old possible records, so occasionally I record an individual and check the pulse rate and pattern. So far, all have been good old Neoconocephalus robustus.
The other two members of that night’s trio both produced regular, brief chirps: one higher pitched and very regular in its rhythm, the other much lower and a little less regular. The higher pitched singer is famous for the way its chirping rate varies with temperature: count the chirps in 13 seconds, and add 40 to get the degrees Fahrenheit. We know this singer as the snowy tree cricket.
That leaves the bass section. The lower pitched continuo is the product of a northern mole cricket. This swale area of Miller Woods is one of only 3 locations where I have found this species to date. I don’t have a photo to show you. True to his name, the mole cricket sings from within his tunnel, and I haven’t yet had a photo op with the critter.
Ah, yes. I see an insistent hand upraised in the back of the class. Yes? Ah, very good. Yes, there is a fourth, more intermittent performer here. Those few added chirps are a fall field cricket’s, practically ubiquitous at this point in the season, and determined to insert himself into any ensemble.