Pachybrachis varians Bowditch, 1909

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 : 25-27

8. Pachybrachis varians Bowditch, 1909 ( Fig. 8 , Map 2A)

Pachybrachys varians Bowditch 1909: 321 . Blatchley 1924: 51 (taxonomy).

Pachybrachis varians: Fattig 1948: 10 (regional species list); Kirk 1970: 86 (regional species list); Balsbaugh and Hays 1972: 35 (taxonomy); Peck and Thomas 1998: 134 (catalogue); Riley et al. 2003: 164 (catalogue); Clark et al. 2004: 162 (plant associations); Ciegler 2007: 183 (taxonomy).

Type Material. A male from the MCZ-BOW, here designated as lectotype and labeled “ Opelousas / La June [printed, white paper] // 6 // varians / Type 6 [hand-inked, white paper] // TYPE / F. C. B. Coll. [printed, pink paper] // Type 8789 [hand-inked, red paper] // LECTOTYPE 8789 / Pachybrachys / varians Bowditch 1909 / R. J. Barney 2017 [printed, red paper]”, was examined, photographed, and dissected ( Fig. 8 ). A female from the MCZ- BOW, labeled “ Opelousas, La June / Pilate VI [printed, white paper] // varians / Type ♀ [hand-inked, white paper] // TYPE / F. C. B. Coll. [printed, pink paper]”, and 13 (766 6♀♀) specimens with identical labels to the lectotype, except one labeled “May”, are herein designated paralectotypes [PARALECTOTYPE / Pachybrachys / varians Bowditch 1909 / R. J. Barney 2017 [printed, red paper]”.

Redescription. Male. Robust, yellow, with fuscous punctures, standard maculae diffuse, lustre dull; L = 1.81–1.98 mm (mean = 1.94 mm, n = 10); W = 0.99–1.10 mm (mean = 1.02 mm, n = 10); L/W = 1.82–1.94 (mean = 1.88, n = 10). Head: Slightly wider than thoracic apex, HW = 0.66–0.74 mm (mean = 0.70 mm, n = 10); eyes moderately separated, IOD = 0.15–0.20 mm (mean = 0.17 mm, n = 10), IOD/HW = 0.19–0.29 (mean = 0.24, n = 10); face yellow with black, diffuse, W-shaped macula connecting vertex and bases of antennae and up to base of upper lobes of eyes, punctation dense, antennae yellowbrown, not reaching elytral declivity. Pronotum: Yellow, dark brown to black M broadly diffuse, leaving small, scattered, yellow spots, lateral margins smooth, PL = 0.59–0.67 mm (mean = 0.63 mm, n = 10); PW = 0.88–0.93 mm (mean = 0.91 mm, n = 10); PL/PW = 0.66–0.73 (mean = 0.69, n = 10). Elytra: Striae distinctly impressed, 2–4 mostly and 7–8 entirely regular (8 th sigmoidal dislocation behind humerus), 5–6 much broken; marginal interspace mostly impunctate. Pygidium: Dark brown to black with 2 oval, yellow maculae. Venter: Dark brown to black, upper sides of last ventrite yellow. Legs: Dark brown to black with standard yellow spots. Genitalia: Median lobe in en-face view with parallel-sided shaft, quickly narrowing to extended terminus, with sclerotized basal plates and reduced PRL. POL, best seen in the lateral view, with ALA nearr 60°. Base wide, then narrowing at ALA. Long setae present along edges of deflexation, but no denticles present at ALM ( Fig. 8 ). Sixty-two males from seven states were dissected.

Female. As in male, except L = 1.97–2.28 mm (mean = 2.17 mm, n = 11); W = 1.03–1.26 mm (mean = 1.18 mm, n = 11); L/W = 1.78– 1.90 (mean = 1.83, n = 11); HW = 0.76–0.87 mm (mean = 0.81 mm, n = 11); IOD = 0.19–0.28 mm (mean = 0.25 mm, n = 11).

Remarks. Bowditch’ s lectotypes and paralectotypes from Opelousas, Louisiana are very distinctive, but very few specimens in collections are identified as P. varians . Fall (1915) reported its distribution from Texas to Georgia and all the way to Key West, Florida. A new species in this current study, P. matthewi , is very similar to P. varians and may eventually be determined to be a more northern variation. Pachybrachis matthewi is larger than P. varians , with reduced maculation, greater interspace punctation, and longer antennae. The median lobe of the aedeagus is significantly wider in en-face view, but the overall configuration is very similar ( Figs. 8 and 9 ).

Distribution. This species is found in the lower Mississippi River Valley and western Gulf coast and from Oklahoma and Texas to Louisiana and Alabama (Map 2A). New state records are

confirmed for three states: Arkansas, Oklahoma, and Tennessee.

Biological Notes. One label referenced collection of this species on Leguminosae in Mississippi.

Specimens Examined. See Appendix 8.

Figures

Fig. 8. Pachybrachis varians. 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.

Fig. 9. Pachybrachis matthewi 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.