Pachybrachis cylindricus Bowditch 1909
Creators: name: Barney, Robert J.
Publisher: name: Zenodo
Year: 2021
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Chrysomelidae
Pachybrachis
Pachybrachis cylindricus

description: 9. PACHYBRACHIS CYLINDRICUS Bowditch, 1909  (Figs. 9, 14B)   
 Pachybrachys cylindricus Bowditch 1909: 291. Fall 1915: 390 (taxonomy).   
 Pachybrachis cylindricus: Riley et al. 2003: 157 (catalog).   
 Type. Bowditch (1909) described P. cylindricus based upon a pair of specimens from Prescott, Arizona. The male specimen, hereby designated lectotype, labeled “ ♂ //Prescott/ Arizona /6 & 7 ’94 [printed, white paper]// cylindricus Bw / ♂ Type [hand-inked, white paper]//TYPE/F. C. B. Coll. [printed, pink paper]// [circular blue disc signifying dissection by RJB]// LECTOTYPE / Pachybrachys / cylindricus Bowditch /R. J. Barney 2021 [printed, red paper]”, was examined, dissected, and photographed (Fig. 9). The female specimen, now a paralectotype, labeled “ ♀ // cylindricus / ♀ Type [hand-inked, white paper]//Prescott/ Arizona /6 & 7 ’94 [printed, white paper]//TYPE/F. C. B. Coll. [printed, pink paper]//Type [printed]/8763 [hand-inked, red paper]// PARALECTOTYPE / Pachybrachys / cylindricus Bowditch /R.J. Barney 2021 [printed, yellow paper]”, was examined and photographed.   
 Redescription. Male. Large, yellow with brown maculae (Fig. 9); L = 3.47–4.23 mm (mean = 3.95 mm, n = 10); W = 1.89–2.39 mm (mean = 2.16 mm, n = 10); L/W = 1.65–1.88 (mean = 1.83, n = 10). Head: Not wider than thoracic apex, HW = 1.30– 1.56 mm (mean = 1.48 mm, n = 10); eyes widely separated, without ocular lines, IOD = 0.39–0.59 mm (mean = 0.47 mm, n = 10); IOD/HW = 0.26– 0.37 (mean = 0.31, n = 10); face yellow with brown macula descending from the vertex and between the upper lobes of eyes, punctation dense in dark areas, antennae progressing from yellow to brown, not reaching elytral declivity. Pronotum: Yellow with reduced M-shaped brown macula, densely punctate, less so at margins and median line, strongly narrowed apically; PL = 1.16–1.44 mm (mean = 1.34 mm, n = 10); PW = 1.60–1.99 mm (mean = 1.87 mm, n = 10); PL/PW = 0.68–0.75 (mean = 0.72, n = 10). Elytra: Yellow with prominent brown maculae on each elytron prior to declivity, thus appearing as a trans-elytral stripe, densely punctate in baso-sutural area, striae irregular. Pygidium: Brown with 2 oval conjoined yellow spots. Venter: Brown with yellow side and apical margins. Legs: Yellow with brown spots, front claws of male greatly enlarged. Genitalia: Median lobe in en-face view shows large, oval OS, with a projecting, grooved terminus, bounded on each side by setal-covered extensions of the DEO, ALM with large wisps. The lateral view reveals a large, dark-edged keel, projecting from the base to the initiation of the wisps. A sub view of the median lobe shows that the keel ridge is very sharp. Nine males from three USA states were dissected.   
 Female. As in male, except L = 4.08–4.59 mm (mean = 4.29 mm, n = 4); W = 2.21–2.61 mm (mean = 2.37 mm, n = 4); L/W = 1.76–1.85 (mean = 1.82, n = 4); HW = 1.61–1.85 mm (mean = 1.69 mm, n = 4); IOD = 0.57–0.72 mm (mean = 0.64 mm, n = 4); IOD/HW = 0.35–0.40 (mean = 0.38, n = 4).   
 Remarks. Externally, P. cylindricus, P. huachuca, and P. ashfork are nearly identical; however, their aedeagal median lobes are readily separable. The median lobes of P. cylindricus and P. crassus are similar, but P. crassus has setal-covered extensions of the DEO on each side of the terminus, which is grooved in P. cylindricus.   
 Distribution. Riley et al. (2003) reported this species from Arizona, California, Nevada and Utah; therefore, the specimens from Idaho are a new state record (Fig. 14B).   
 Biological Notes. A series of P. cylindricus was collected on Juniperus sp. and Juniperus osteosperma (Torr.) Little (Cupressaceae) in Utah.   
 Specimens Examined. Lectotype, paralectotype + 13 specimens. USA: ARIZONA: Yavapai Co., Prescott, vi-vii.1894 [1♂ 1♀, LECTOTYPE and PARALECTOTYPE, MCZ-BOW]. IDAHO: Oneida Co., Curlew Natl. Grassland, Jacobson Field, 14.vi.2004, S. M. Clark and M. H. Goodman [1♂ 1♀, EGR#134, BYUC]. UTAH: Juab Co., Topaz Mountain, 39.6965°N 113.0977°W, 1,765 m, 21.vi.2017, UV light, J. R. Jones [3♂♂, RJBC]; Fish Springs Range, 2 mi SE Summit of George H. Hansen Peak, 39.709°N 113.404°W, 15.v.2020, ex. Juniperus osteosperma, S. M. Clark [1♂, BYUC]; Utah Co., Neebo Creek, 3.5 mi above junction Thistle Creek, 8.vi.2002, S. M. Clark [1♀, BYUC]; Washington Co., 2.5 mi NW Leeds, 4,300 ft, 37.2715°N 113.3825°W, 15.v.2015, ex. Juniperus sp., R. J. Barney [1♂ 1♀, RJBC]; same data, except 3 mi NW Leeds, 4,825 ft, 37.2723°N 113.3973°W [1♂, RJBC]; Leeds Canyon, 10.vi.1965, D. W. Davis [2♂♂, BYUC]; Red Cliffs Campground, 24.v.1985, C. R. Nelson [1♂, BYUC].
description: Published as part of Barney, Robert J., 2021, Definition and Revision of the cylindricus Species-Group of North American Pachybrachis Chevrolat (Coleoptera: Chrysomelidae: Cryptocephalinae), Including Descriptions of Six New Species, pp. 723-748 in The Coleopterists Bulletin 75 (4) on page 739, DOI: 10.1649/0010-065X-75.4.723, http://zenodo.org/record/13252037