Ditch Hopping: Northern Mole Crickets

by Carl Strang

Last year, while driving a rural road at dusk in Newton County, Indiana, I stopped beside a drainage ditch to listen for slightly musical coneheads. Instead I heard a northern mole cricket, and I realized that I needed to turn off the car engine to hear the low-pitched song.

Northern mole cricket specimen (Neocurtilla hexadactyla). This face-on view shows the modified front legs that make this cricket such a good digger.
Recording of northern mole cricket calling song

This turned out to be a lucky observation, as it opened a way for me to conduct my research profitably in this covid19 year. I spent most of the peak singing insect season ditch hopping. I used GoogleEarth and DeLorme map books to identify likely spots where rural roads intersect drainage ditches and streams. Such stops kept me away from concentrations of people.

Typical drainage ditch, Kankakee County

This method gave me a cluster of mole cricket locations on ditches and streams in northeastern Kankakee County, Illinois, all tributaries of the Kankakee River. I also added county records in Pulaski and Fulton Counties, Indiana. Otherwise, the many evenings of searching mainly told me where mole crickets are not, and I have concluded that I will add no more counties in Illinois or Wisconsin.

Map of the Chicago region showing where I have found northern mole crickets (black dots) and identifying counties where there are old records for the species (white dots).

I have satisfied myself that I am not going to find them in Cook County, Illinois, but there still are a few places to check next year in St. Joseph County, Indiana, and Berrien County, Michigan.

Japanese Burrowing Crickets Spreading Rapidly

by Carl Strang

The Japanese burrowing cricket is, as the name suggests, an oriental species that was accidentally introduced to this country at one or more coastal ports. They have spread out from there, and I first encountered them in the Chicago region at Bendix Woods, a St. Joseph County park, in 2014.

Japanese burrowing cricket, Velarifictorus micado

Since then I have found them increasingly at sites throughout the southern portion of the Chicago region.

Counties of the Chicago region, with years when I first observed Japanese burrowing crickets in each.

Fulton County, at the southeast corner of the region, is the most remote from my home, so I don’t go there often. I rather imagine that Japanese burrowing crickets are in the city of Rochester, at least.

Note that I added 7 counties this year. This is in part because they are increasing in the region, and in part because I encountered them frequently while ditch hopping (more on that in later posts). Rural drainage ditches may be major dispersal corridors, along with human-assisted transport in landscape and building materials. The crickets also may fly to expand their range, but this possibility remains speculative.

Japanese burrowing crickets have been ubiquitous and abundant in Indianapolis for years. Last year I found them to be common in Rensselaer, Indiana, one of the southernmost cities of the Chicago region. There is every reason to believe that they will become abundant through most or all of the region over the next decade. They thrive in loose landscaping stone and in lawns, which are not prime habitat for our other members of the field cricket group, so it is possible there will be little effect on our native species.

Here is the most common calling song of the Japanese burrowing cricket:

Perhaps less commonly heard is this alternative:

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