March 7, 2017 at 7:49 am (singing insects)
Tags: Amblycorypha longinicta, common virtuoso katydid, coral-winged grasshopper, delicate meadow katydid, Neoconocephalus lyristes, Neocurtilla hexadactyla, Neotibicen pronotalis, northern mole cricket, Orchelimum delicatum, Pardalophora apiculata, slender conehead, Walker's cicada
by Carl Strang
Planning for the coming singing insects field season has been one of my major occupations this winter. I am looking forward to visiting many new sites, and hope to find some of the species that historically occurred in the Chicago region but which have eluded me so far. Part of that process has been to visit insect collections, gaining information on those species and taking photographs that will help me recognize them.
While at the Purdue University and Illinois Natural History Survey collections, the two museums I have visited so far, I also photographed specimens of species that I have heard but not yet photographed in the field. This will enhance next year’s edition of the guide.
The northern mole cricket is one of those species. This front-end view shows why that cricket is well named.
A note on one specimen said it was collected while flying around in someone’s garage. I had not been aware that northern mole crickets can fly.
Another plan for the upcoming guide is to add pages for the species that have been documented in the Chicago region, but which I have not yet found. Researching those species is getting me better prepared to find them.
There is a Kankakee County record for the common virtuoso katydid, in or near the Illinois Kankakee Sands preserve. That is one species I will be seeking this year.
Walker’s cicada has been collected in a few locations around the region. I need to be alert for its distinctive song in the coming season.
The coral-winged grasshopper will be one of the earliest species for me to seek this spring. They overwinter as nymphs, and have been found mainly in May in past years. I have several locations to check.
The large spots on the sides of the wings, along with the golden wing edges and brightly colored hind wings, are distinguishing features of coral-winged grasshoppers.
Female delicate meadow katydids have unusually long ovipositors. This example will help me distinguish them from green-faced individuals of the dusky-faced meadow katydid. I have not given up hope for the delicate meadow katydid in the region.
Another species I still hope to find is the slender conehead. This one, collected at Illinois Beach State Park in 1906, shows the main distinguishing features of that wetland species: the front of the cone is all black, and there is a right-angle bend in the contour of the pronotum’s posterior edge.
All of this is getting me fired up, but I still have two months to wait. Maybe another museum visit is in order…
April 10, 2013 at 5:58 am (singing insects)
Tags: bush cicada, Camnula pellucida, Chloealtis abdominalis, Chloealtis conspersa, Cicadetta calliope, clearwinged grasshopper, common grass cicada, crepitation, Gomphocerinae, Oedopodinae, sprinkled broad-winged grasshopper, stridulation, Thomas's broad-winged grasshopper, Tibicen dorsatus, Tibicen pronotalis, Walker's cicada, Whitefish Point
by Carl Strang
Thanks to two publications, one very new and one very old, I have been able to fill out my list of singing insects that may occur in the Chicago region by adding possible cicada and grasshopper species. The new reference is a monograph published last year by the Entomological Society of America, The Cicadas (Hemiptera: Cicadoidea: Cicadidae) of North America North of Mexico, by Allen F. Sanborn and Maxine S. Heath. There is not a lot of natural history information in it, as its focus is on sorting out species and their relationships, but it is complete in its species coverage and at least outlines the range for each. It allowed me to add three possible cicadas to my list. Two of them are tallgrass prairie specialists that are known in Illinois but may not occur this far north: the common grass cicada (Cicadetta calliope), a tiny early season species, and the bush cicada (Tibicen dorsatus), a late season species. The third added cicada, Walker’s cicada (Tibicen pronotalis), is a large insect of woodlands along streams.
The old reference is W.S. Blatchley’s Orthoptera of Northeastern America with Especial Reference to the Faunas, of Indiana and Florida. This one was published back in 1920, and is available as a 2012 reprint by the Forgotten Books company. The text is generally readable, but somewhat faint. The taxonomy and nomenclature for the grasshoppers have been remarkably stable over time, and most scientific names haven’t changed. I was able to make the necessary updates by referring to the most recent popular guide to grasshoppers, katydids and crickets by Capinera, Scott, and Walker. Blatchley’s book contains considerable natural history information, and is reminiscent of the Bent’s Life Histories of Birds in its style.
There are two subfamilies of singing grasshoppers. The stridulating slantfaced grasshoppers, subfamily Gomphocerinae, sing while perched or resting on the ground, lifting and lowering their back legs to rub them against the wings, producing a rapid zuzz-zuzz-zuzz sound that is distinct from other insect songs, but to my ear this stridulation seems much the same in different species. The only one for which I have a photograph is a northern species.
Thomas’s broad-winged grasshopper at Whitefish Point on the Upper Peninsula of Michigan.
That grasshopper does not occur as far south as our area, but another member of its genus, the sprinkled broad-winged grasshopper (Chloealtis conspersa) is one I’ll listen for, along with 7 other candidates in this subfamily. Though their songs probably are much the same, their habitats and details of their appearance are different.
The other singing subfamily of grasshoppers is Oedipodinae, the band-winged grasshoppers. These produce their sounds in a different way, crepitation, by rattling or rubbing together their wings in flight. The potential additions to the local list number a dozen species. One of these also was prominent at Whitefish Point.
A pair of clear-winged grasshoppers, Camnula pellucida
The literature suggests more variation in the sounds produced by the crepitation method, but these grasshoppers are flying when they sing, and so should be easier to locate.