by Carl Strang
In September and early October I revisited driving routes I had followed in the spring, listening for fall field crickets (FFC) as I had done in May and June for spring field crickets (SFC). Then, I had noticed that SFC were limited largely to places where dense herbaceous vegetation provided shelter for overwintering nymphs. FFC spend the winter as eggs buried in the soil, and so are less vulnerable to the stresses of the cold season. Here is the current map showing the distribution of the two species in DuPage County:
Clearly both species occur together in most places. Fall field crickets are more likely to occur alone than spring field crickets, in keeping with the spring observation. This year’s surveying was done in western DuPage, and next year I plan to fill in more of the eastern part of the county. If the results continue to show the pattern that appears to be emerging to date, the eastern part of the county, which became urbanized earlier and more completely than the western part, will continue to show fewer SFC because of its historical paucity of safe nymphal overwintering sites. The existence of locations with SFC but no FFC remains to be explained.