Spring Field Cricket Survey

by Carl Strang

The spring and fall field crickets arguably are our most familiar singing insects. The two species are common, span the season from spring to late fall, and their identical songs are easily recognized chirps. Physically, spring and fall field crickets are essentially identical.

Fall field cricket (female)

Fall field cricket (female)

Developmentally and ecologically they are different, however. These days we are hearing spring field crickets, which overwinter as nymphs, mature in late April or May, and finish in mid-July. The figurative baton then passes to the fall field crickets, which overwinter as eggs in the soil, mature after mid-July, and continue into October or early November. These are two different survival regimes, and the spring field crickets arguably have the tougher challenge. Winter would seem to be easier to survive as a buried quiescent egg than as a nymph. I have been testing this idea by surveying the two species in DuPage County, and recently completed the spring field cricket part of the survey. I drove 3 routes in eastern DuPage in the evenings, listening with the car windows open. The crickets’ songs are sufficiently penetrating that I can expect to hear them, at least well enough to get a general sense of where they are and where they’re not.

Here’s the composite map to date. Green dots represent locations with both species, yellow show places with only fall field crickets, and blue with only spring field crickets (so far).

Here’s the composite map to date. Green dots represent locations with both species, yellow show places with only fall field crickets, and blue with only spring field crickets (so far).

As you can see, there are many blue dots in the eastern half of the county. Many, perhaps most or all, will become green when I repeat these routes in late summer or early autumn. The impression I formed while driving around is that there are pockets of crickets, scattered and somewhat isolated, with a lot of empty space between them. Some populations are relatively large, but some of the blue dots represent single singers. Spring field cricket habitat is narrower, it seems, needing to supply better winter shelter, but I will be better able to draw tentative conclusions after the survey drives for fall field crickets later this year.

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