Jumping Bush Crickets 2015

by Carl Strang

Of the many species of singing insects that have shifted their range boundaries significantly northward in the last half-century, the one that is continuing to move most rapidly is the jumping bush cricket.

Jumping bush cricket

Jumping bush cricket

In recent years I have been tracing the northernmost locations where I am hearing the distinctive songs of this cricket in northeast Illinois.

Chicago region map of jumping bush cricket locations. Black dots mark counties where I have found the species to date. Red stars indicate specific locations where I found northernmost crickets singing in 2014. Yellow stars mark places farther north where I heard them in 2015.

Chicago region map of jumping bush cricket locations. Black dots mark counties where I have found the species to date. Red stars indicate specific locations where I found northernmost crickets singing in 2014. Yellow stars mark places farther north where I heard them in 2015.

The line marking the front of this expansion is diagonal, southwest to northeast, an orientation that seems to point back toward Indiana as the source of this spread. In the central part of the line I found no indication of an advance from 2014 to 2015, but elsewhere there was a shift of about half a mile. If at some point the movement stalls out, I would expect the west end of the line to catch up with the east end and even up latitudinally, unless there is a Lake Michigan climatic influence.

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