by Carl Strang
Up to this point I have reported singing insect distributions in the Chicago region at the county level. For instance, here is an Allard’s ground cricket (Allonemobius allardi) and its species distribution by county.
Male Allard’s ground cricket
The black dots simply show that I have found Allard’s in every county of my study region.
But I have a lot more data than that which I wanted to share. Also, I thought that maybe a finer grained mapping approach might reveal new questions for me to investigate. I had a spreadsheet with a species list for every site I have visited. So, I recently created a series of maps showing the sites where I have found each species over the years. Here is the resulting map for Allard’s ground cricket:
Filled circles indicate sites where I have observed Allard’s ground crickets. Open circles are places I have visited where I haven’t (yet) noted that species.
As you can see, this is a widespread and frequently encountered cricket. The map reveals significant areas with no sites. Some of these are vast empty (from a biodiversity standpoint) agricultural regions, but still I should give them more attention.
One more example for today. The long-spurred meadow katydid (Orchelimum silvaticum) reaches its northern range limit in the Chicago region.
Long-spurred meadow katydid, male
The county-level map showed this, but the site level map makes it even clearer.
The northernmost sites where I have found long-spurred meadow katydids line up impressively at the same latitude.
These two examples simply emphasize conclusions I had drawn previously. Some intriguing questions were raised in other cases, as I will share in upcoming posts.
