Pachybrachis calcaratus Fall, 1915

Barney, Robert J., 2022, Monitoring of Pachybrachis Chevrolat (Coleoptera: Chrysomelidae: Cryptocephalinae) Diversity and Abundance in Illinois for 140 Years: Recent Detections and Presumed Extirpations, The Coleopterists Bulletin 76 (4), pp. 489-496 : 492-493

Pachybrachis calcaratus Fall (Presumed EXtirpated)

Except for a single event in 1947, when> 70% of all P. calcaratus were collected, this species has been relatively uncommon in Illinois. The lectotype of P. calcaratus is from Hinsdale , DuPage County. Barney (2018a) reported 81% of the specimens as found from three states adjacent to the Mississippi River: Illinois, Louisiana and Mississippi.

Pachybrachis caroleae Barney (Presumed EXtirpated)

All four specimens of P. caroleae were collected during 1981 ( Barney 2018a). The only known specimens are from Cole Creek Hill Prairie in Greene County, which Evers (1955) described as South Eldred Hill Prairie.This hill prairie is on private property and recent access was not granted by the owner. It is not inconceivable that after more than forty years this hill prairie and this species is no longer extant.

Pachybrachis charlotteae Barney (RelatiVely Secure)

Pachybrachis charlotteae was not collected in Illinois until the 1950s ( Table 2). Barney (2018a) reported this species from Midwestern states between the Appalachian Mountains and 100 th meridian. This species was incorrectly labeled as Pachybrachis relictus Fall in the INHS collection. It is now one of the most common Pachybrachis species found in Illinois prairies in the last 40 years.

Pachybrachis deceptor Riley and Barney (RelatiVely Secure)

Pachybrachis deceptor remained undetected in Illinois, and much of the eastern United States, until the 2000s ( Table 2). Riley and Barney (2015) reported this species as occurring west of a line running from western North Carolina to northern Illinois, and being broadly sympatric with Pachybrachis m-nigrum (Melsheimer), with which it bears a strong outward resemblance. This species was incorrectly labeled as P. m-nigrum in collections. Examination of the median lobes of the aedeagus allows easy separation of the two species .

Pachybrachis diversus Fall (RelatiVely Recent Detection)

Pachybrachis diversus remained undetected in Illinois until the 1980s ( Table 2). Barney (2018b) reported P. diversus as primarily found in the Great Plains. Pachybrachis diversus is relatively common on Salix species in Illinois and is expected to remain so in the future. There is no reasonable explanation why it was not reported in Illinois before 1980.

Pachybrachis dixianus Fall (RelatiVely Recent Detection)

Pachybrachis dixianus is uncommon in Illinois and remained undetected in the state until the 1950s ( Table 2). Barney (2018a) reported P. dixianus as found in the south-Atlantic coastal states, with Illinois at the northern limit of its known range.