Pachybrachis jacobyi Bowditch, 1909

5. Pachybrachis jacobyi Bowditch, 1909 ( Fig. 4 View Fig , Map 1 View Map 1 )

Pachybrachys jacobyi Bowditch 1909: 240 ; Fall 1915: 337 (taxonomy).

Pachybrachis jacobyi: Riley et al. 2003: 158 (catalog).

Type. Bowditch (1909) examined many specimens from five US states for his description without explicitly designating a type; however, he labeled two specimens as “Type” with the following labels: “ ♂ // St. George / Utah, July / Wickham [printed, white paper] // jacobyi ♂ [handinked, white paper] // TYPE / F. C. B. Coll. [printed, pink paper] // Type [printed] / 8658 [handinked, red paper]” and “ ♀ // St. George / Utah, July / Wickham [printed, white paper] // jacobyi ♀ [handinked, white paper] // TYPE / F. C. B. Coll. [printed, pink paper]”. Both of these specimens had a small, corked vial attached to the pin that presumably contained genitalia. No attempt was made to open these vials as a number of “cotypes” (see Specimens Examined ), as labeled by Bowditch , were available for aedeagal dissection. A male, hereby designated lectotype, labeled “ ♂ // St. George / Utah, July / Wickham [printed, white paper] // jacobyi cotype [hand-inked, white paper] // [circular blue disc signifying dissection by RJB] // LECTOTYPE / Pachybrachys / jacobyi Bowditch / R. J. Barney 2020 [printed, red paper]”, was examined, dissected, and photographed ( Fig. 4 View Fig ) .

Redescription. Male. Moderately robust, pale, whitish-grayish yellow, densely and diffusely punctate ( Fig. 4 View Fig ); L = 2.31–2.53 mm (mean = 2.45 mm, n = 6); W = 1.18–1.36 mm (mean = 1.27 mm, n = 6); L/W = 1.90–1.96 (mean = 1.93, n = 6). Head: Wider than thoracic apex, HW = 0.92–1.02 mm (mean = 0.97 mm, n = 6); eyes widely separated, with ocular lines, IOD = 0.35–0.42 mm (mean = 0.38 mm, n = 6); IOD/HW = 0.36–0.41 (mean = 0.39, n = 6); face whitish-grayish yellow, densely and diffusely punctate, ocular lines blackish above eyes, fading to colorless; antennae not reaching elytral declivity. Pronotum: Whitish-grayish yellow, less densely punctate, even less so at margins; PL = 0.72–0.82 mm (mean = 0.77 mm, n = 6); PW = 1.02–1.13 mm (mean = 1.07 mm, n = 6); PL/PW = 0.70–0.73 (mean = 0.71, n = 6). Elytra: Whitish-grayish yellow, densely and diffusely punctate, submarginal stria semi-regular. Pygidium: Yellow. Venter: Dark brown to blackish with yellow side and apical margins. Legs: Yellow, front claws of male not enlarged. Genitalia: Median lobe in en-face view with large oval OS, rounded ALM joining to form very large T, with setae visible on either side. Lateral view reveals a slight ALA with setae, no ridges or keel. Three males from three USA states were dissected.

Female. As in male, except L = 2.46–3.20 mm (mean = 2.73 mm, n = 10); W = 1.26–1.72 mm (mean = 1.43 mm, n = 10); L/W = 1.86–1.97 (mean = 1.92, n = 10); HW = 0.91–1.24 mm (mean = 1.06 mm, n = 10); IOD = 0.36–0.53 mm (mean = 0.45, n = 10); IOD/HW = 0.36–0.48 (mean = 0.42, n = 10).

Remarks. Pachybrachis jacobyi is easily separated from the other primarily yellow, densely punctate species described here by its large size, broad face with widely spaced eyes, and distinctive aedeagal median lobe.

Distribution. This species is known from California to Texas and north to Colorado and South Dakota in the USA ( Map 1 View Map 1 ).

Biological Notes. Clark et al. (2004) cited Hymenoclea sp. (Asteraceae) , Atriplex sp. (Amaranthaceae) , and Adenostoma fasciculatum Hook. & Arn. (Rosaceae) as potential host plants.

Specimens Examined. Types, cotypes, lectotype + 6 specimens. USA: ARIZONA: Navajo Co., Winslow, Wickham [ 1♀, COTYPE, MCZ-BOW]; unknown county, Ariz. [ 1♂ 1♀, “COTYPES, called livens by Jacoby”, MCZ-BOW]; Arizona , Morrison , Hubbard and Schwarz Collection [ 1♂ 1♀, Fall 1915 Revis., MCZ-BOW]. CALIFORNIA: Lassen Co. , Amedee , 4,200 ft., 21-28.vii, Wickham [ 3♀♀, COTYPES, MCZ-BOW]; Mono Co. , Bridgeport , 6,465 ft., 12-15.vii, Wickham [ 1♂ 1♀, COTYPES, MCZ-BOW]. COLORADO: Alamosa Co. , 4-10 mi N jct. 160 on hwy. 150, 12.vii.1995, E. G. Riley [ 2♂♂ 2♀♀, EGR#86, RJBC]. UTAH: Washington Co. , St. George , vii, Wickham [ 2♂♂ 2♀♀, TYPES & COTYPES, MCZ-BOW].