Pachybrachis caroleae Barney, 2018

Barney, Robert J., 2018, Definition and Revision of the Atomarius Species-Group of North American Pachybrachis Chevrolat (Coleoptera: Chrysomelidae: Cryptocephalinae), Including Descriptions of Nine New Species, The Coleopterists Bulletin 72 (1), pp. 9-74 : 32-35

13. Pachybrachis caroleae Barney , new species Zoobank.org/ urn:lsid:zoobank.org:act:81EA955D-ACAE-4E89-B248-3F49D539449C ( Fig. 13 , Map 2B)

Holotype. Male , labeled “IL: Greene Co. / Cole Creek Hill Prairie / 1.7 mi S of Eldred / June 24, 1981 / R. J. Barney [printed, white paper] // [circular blue disc signifying dissection by RJB] // HOLO- TYPE / Pachybrachis / caroleae / R. J. Barney 2017 [printed, red paper].” Deposited in MCZ. The specimen is point-mounted with genitalia affixed to point. It is in excellent condition with all appendages intact. There are three paratypes (16 2♀♀) with identical collecting data.

Paratypes. 16 2♀♀. See Appendix 13.

Description. Male. Yellow, with dark brown to black punctures, pronotal V-shaped macula and transverse maculae near elytral declivity; L = 1.64– 1.75 mm (mean = 1.69 mm, n = 2); W = 0.89–0.92 mm (mean = 0.90 mm, n = 2); L/W = 1.85–1.91 (mean = 1.88, n = 2). Head: Slightly wider than thoracic apex, HW = 0.61–0.63 mm (mean = 0.62 mm, n = 2); eyes narrowly separated, IOD = 0.09–0.12 mm (mean = 0.10 mm, n = 2); IOD/HW = 0.14–0.19 (mean = 0.17, n = 2); face yellow with dark brown macula between upper lobes of eyes connecting to vertex, antennae yellow-brown, not reaching elytral declivity. Pronotum: Yellow, with dark brown standard M-shaped macula reduced to Vshaped macula, punctation dense in dark areas, more sparsely placed in pale areas, especially along lateral margins, PL = 0.45–0.50 mm (mean = 0.48 mm, n = 2); PW = 0.72–0.80 mm (mean = 0.76 mm, n = 2); PL/PW = 0.61–0.63 (mean = 0.62, n = 2). Elytra: Yellow with standard brown macula reduced, transverse maculae near elytral declivity most pronounced; striae mostly regular except for 5–7, marginal interspace impunctate. Pygidium: Finely punctate, weakly convex; dark brown, with 2 confluent, oval, yellow maculae. Venter: Dark brown to black, yellow spot on last ventrite. Legs: Light brown with yellow femoral and tibial spots. Genitalia: Median lobe in en-face view with large, oval OS within parallel-sided shaft, with reduced PRL. Thickened sides rapidly narrow to extended POL, ALM deflexed at near 90°, thereby creating a small, triangular, arrowhead-shaped area with gently pointed terminus and 2 posteriorly projecting denticles ( Fig. 13 ).

Female. As in male, except L = 1.71–1.95 mm (mean = 1.83 mm, n = 2); W = 0.93–1.07 mm (mean = 1.00 mm, n = 2); L/W = 1.82–1.83 (mean = 1.83, n = 2); HW = 0.63–0.71 mm (mean = 0.67 mm, n = 2); IOD = 0.15–0.16 mm (mean = 0.15 mm, n = 2); IOD/HW = 0.21–0.25 (mean = 0.23, n = 2).

Etymology. This species is named in recognition of Carole Lee Barney Keel, Louisville, Kentucky.

Remarks. This species presently is known from only four specimens collected by the author over 35 years ago in 1981, on one hill prairie of the Illinois River. Evers (1955) described this as South Eldred Hill Prairie, consisting of 4.5 acres of southwest facing slopes in 1950. The close-set eyes, V-shaped pronotal macula, and unique median lobe make this species easy to identify.

Distribution. This species is only found on one hill prairie in Greene County, central Illinois (Map 2B).

Biological Notes. No information is available.

Specimens Examined. See Appendix 13.

Figures

Fig. 13. Pachybrachis caroleae, holotype. A) Dorsal habitus, B) Lateral habitus, C) Face, D) Pygidium, E) Median lobe of aedeagus, lateral view, F) Median lobe of aedeagus, en-face view.