Pachybrachis nobilis Fall, 1915

Barney, Robert J., 2023, Redescriptions of the Pachybrachis Chevrolat (Coleoptera: Chrysomelidae: Cryptocephalinae) of Arizona, Including New Synonymies, State Records, Plant Associations, and Descriptions of New Species: The Robust Species, The Coleopterists Bulletin 77 (3), pp. 439-459 : 449-451

10. Pachybrachis nobilis Fall, 1915 ( Fig. 5 )

Pachybrachys nobilis Fall 1915: 409 . Pachybrachis nobilis : Riley et al. 2003: 160

(catalog).

Type. Fall (1915) described P. nobilis from a series collected in Williams, Arizona. Fall’s male type, hereby designated lectotype, labeled “Williams / 18.7 [hand-inked] Ar [printed, white paper] // Barber& / SchwarzCol [printed, white paper] // TYPE [printed] / nobilis [hand-inked, white paper] // M.C.Z. / Type [printed] / 24954 [hand-inked, red paper] // [circular blue disc signifying dissection by RJB] // LECTOTYPE / Pachybrachys / nobilis Fall / R. J. Barney 2023 [printed, red paper]”, was examined, dissected, and photographed ( Fig. 5 ). Other specimens from the Williams , Arizona series are paralectotypes, 1♀ ( MCZ-FALL) and 1♂ 1♀ ( USNM), with the additional label “ PARALECTOTYPE / Pachybrachys / nobilis Fall / R. J. Barney 2023 [printed, yellow paper]” .

Redescription. Male. Very large, yellow-red with brown-black maculae ( Fig. 5 ); L = 5.20– 5.69 mm (mean = 5.38 mm, n = 4); W = 2.59–2.96 mm (mean = 2.71 mm, n = 4); L/W = 1.92–2.03 (mean = 1.98, n = 4). Head: Slightly wider than thoracic apex, HW = 1.64–1.73 mm (mean = 1.67 mm, n = 4); eyes widely separated, IOD = 0.47–0.55 mm (mean = 0.51 mm, n = 4); IOD/HW = 0.28–0.33 (mean = 0.31, n = 4); face yellow with red punctures, red median line descending from vertex to middle of eyes; antenna progressing from yellow-red to brown, not reaching elytral declivity. Pronotum: Yellow, heavily red-punctate, less so at margins, with obscure M-shaped red maculae; PL = 1.53–1.66 mm (mean = 1.59 mm, n = 4); PW = 2.43–2.67 mm (mean = 2.51 mm, n = 4); PL/PW = 0.61–0.66 (mean = 0.63, n = 4). Elytra: Yellow, heavily punctate with brown-black punctures and maculae, striae irregular. Pygidium: Yellow with brown median line. Venter: Brown. Legs: Yellow-red, front claws of male not enlarged. Genitalia: Median lobe in en-face view very large, long, parallel-sided with oval OS, extensive POS ending in squared-off T; medial lobe in lateral view with inflated base to wide, tubular lobe with setae on side of squared T. Four males from Arizona and New Mexico were dissected.

Female. As in male, except L = 4.82–6.38 mm (mean = 5.96 mm, n = 8); W = 2.51–3.33 mm (mean = 3.03 mm, n = 8); L/W = 1.92–2.05 (mean = 1.96, n = 8); HW = 1.76–2.05 mm (mean = 1.90 mm, n = 8); IOD = 0.48–0.70 mm (mean = 0.65 mm, n = 8); IOD/HW = 0.29–0.39 (mean = 0.34, n = 8).

Remarks. Pachybrachis nobilis is the largest species of Pachybrachis in USA. Confusion with large reddish specimens of P. fuscipes and P. sanrita , and large specimens of Pachybrachis varicolor

Suffrian is possible, but the very large aedeagal median lobe of P. nobilis is distinctive.

Distribution. Riley et al. (2003) reported P. nobilis only from Arizona, making the New Mexico records reported here a new state record.

Biological Notes. Clark et al. (2004) reported specimens collected from Pinus ponderosa Douglas ex C. Lawson ( Pinaceae ).

Specimens Examined. Lectotype, paralectotypes plus 8 specimens. USA: ARIZONA: Cochise Co., Huachuca Mts. , 9,000 ft., 5.vii [2♀♀, MCZ-FALL] ;

Coconino Co., Williams, 18.vii, Barber and Schwarz [1♂, LECTOTYPE, MCZ-FALL]; same data, except 23–30.vii [1♀, PARALECTOTYPE, MCZ-FALL; 1♂ 1♀, PARALECTOTYPES, USNM]; Williams , 28.vi.1948, B. E. White [1♂ 1♀, MCZ-FALL]; Huachuca Mts. , 8,500 ft., 5.x.1968 [1♀, FSCA]; Huachuca Mts. , Copper Canyon , 8.vi.1975, K. Stephan [1♂, FSCA]. NEW MEXICO: Grant Co. , Black Range , 8,100 ft., Wrights Cabin on Hwy. 152, 32.91353°N 107.77628°W, 14.vii.2012, E. G. Riley [1♂ 1♀, RJBC] .

Figures

Fig. 5. Pachybrachis nobilis, Williams, Arizona, lectotype. 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.