Pachybrachis alticola, Fall, 1915

Barney, Robert J., 2021, Redescription of Five Species of Pachybrachis Chevrolat (Coleoptera: Chrysomelidae: Cryptocephalinae) of the Western USA, Including New Synonymies, Records of Greatly Expanded Ranges into the Eastern USA, and New Plant Associations, The Coleopterists Bulletin 75 (2), pp. 485-496 : 493-495

3. PACHYBRACHIS AltIColA Fall, 1915

( Figs. 5 , 6 )

Pachybrachys alticola Fall 1915: 442 . Pachybrachis alticola : Riley et al. 2003: 155 (catalog).

Type. Fall’s (1915) male type, hereby designated lectotype, labeled “ ♂ // Beulah / N. M. / 7/02 [hand-inked, white paper] // TYPE [printed] / alticola [hand-inked, white paper] // H.C. FALL / COLLECTION [printed, white paper] // M.C.Z. / Type [printed] / 24914 [hand-inked, red paper] // [circular blue disc signifying dissection by RJB] // LECTOTYPE / Pachybrachys / alticola Bowditch / R. J. Barney 2020 [printed, red paper]”, was examined, dissected, and photographed ( Fig. 5 ).

Redescription. Male. Yellow, elytra with standard black maculation, black pronotal M ( Fig. 5 ); L = 2.60–3.03 mm (mean = 2.80 mm, n = 3); W = 1.35– 1.56 mm (mean = 1.44 mm, n = 3); L/W = 2.48–2.55 (mean = 2.52, n = 3). Head: Slightly wider than thoracic apex, HW = 0.95–1.05 mm (mean = 1.00 mm, n = 3); IOD = 0.31–0.34 mm (mean = 0.33 mm, n = 3); IOD/HW = 0.40–0.43 (mean = 0.42, n = 3); face yellow with thin brown macula descending from vertex to between eyes; ocular lines near upper lobes of eyes; antenna not reaching elytral declivity. Pronotum: Yellow, black M-shaped macula well defined; incomplete punctation, side margins smooth; PL = 0.75–0.90 mm (mean = 0.81 mm, n = 3); PW = 1.14–1.27 mm (mean = 1.21 mm, n = 3); PL/PW = 0.83–0.92 (mean = 0.87, n = 3). Elytra: Yellow, baso-sutural punctures confused, striae mostly regular, standard maculae black. Pygidium: Yellow, with base, a median and two side spurs black. Venter: Black, upper sides of last ventrites yellow. Legs: Yellow, front claws not enlarged. Genitalia: Median lobe in en-face view parallel-sided, rounding at ALM to terminus. In lateral view, median lobe rather generic with short setae at ALA. Three males from two states were dissected.

Remarks. Fall (1915) listed P. alticola as possibly a darker form of P. laevis . However, examination of the median lobes allows quick separation of the species. The opportunity to examine a pair of specimens from Garland, Colorado listed in Fall (1915; see Distribution section) revealed them to have distinct ocular lines and a different median lobe; thus, they are not P. alticola .

Distribution. Riley et al. (2003) reported P. alticola from Arizona, Colorado, New Mexico, and Alberta, Canada ( Fig. 6 ).

Biological Notes. Ward et al. (1977) reported P. alticola from mesquite ( Prosopis ) ( Fabaceae ).

Specimens Examined. Lectotype, paralectotype + 1 specimen. USA: COLORADO: El Paso Co., Colorado Springs , 6,000 to 7,000 ft., vi, Wickham Collection [ 1♂, PARATYPE, USNM]. NEW MEXICO: San Miguel Co., Beulah, 2.vii [ 1♂, LECTOTYPE, MCZ-FALL]; Socorro Co. , viii.1894, Snow [ 1♂, HCF, SEMC].

Figures

Fig. 5. Pachybrachis alticola, lectotype, Beulah, New Mexico. Habitus: A) Dorsal, B) Lateral. C) Face. D) Pygidium. Median lobe of aedeagus: E) En-face view, F) Lateral view.

Fig. 6. Distribution of Pachybrachis species, based upon specimens examined.P.laevis (black); P. nubilus (orange), and P. alticola (purple).