Pachybrachis integratus Fall, 1915

Barney, Robert J., 2019, Definition and Revision of the Pubescens Species-Group of North American Pachybrachis Chevrolat (Coleoptera: Chrysomelidae: Cryptocephalinae), Including Descriptions of Three New Species, The Coleopterists Bulletin 73 (4), pp. 1017-1048 : 1026-1028

5. Pachybrachis integratus Fall, 1915 ( Figs. 5 , 13B ; Map 1A)

Pachybrachys integratus Fall 1915: 327 . Pachybrachis integratus: Riley et al. 2003: 158

(catalogue).

Type Material. Fall’ s female P. integratus , labeled “Col. River / CAL. // Not in / Lec. Coll // ♀ // TYPE [printed] / integratus [hand-inked, white paper] // M.C.Z. / Type [printed] / 24946 [handinked, red paper] // H. C. FALL / COLLECTION // LECTOTYPE / Pachybrachys / integratus Fall 1915 / design. R. J. Barney 2019 [printed, red paper]”, was examined and photographed and is hereby designated lectotype to stabilize the epithet ( Fig. 13B ) .

Redescription. Male. Pale yellow with fuscous markings and sparse, white pubescence ( Fig. 5 ); L = 2.73–3.08 mm (mean = 3.02 mm, n = 4); W = 1.37–1.55 mm (mean = 1.50 mm, n = 4); L/W = 1.99–2.04 (mean = 2.01, n = 4). Head: Slightly wider than thoracic apex, HW = 0.91–1.02 mm (mean = 0.98 mm, n = 4); eyes nearly contiguous, IOD = 0.05–0.08 mm (mean = 0.07 mm, n = 4); IOD/HW = 0.05–0.08 (mean = 0.07, n = 4); face yellow with impressed line between eyes, evenly punctate; antennae yellow-brown, not reaching elytral declivity. Pronotum: Yellow-brown, widest at basal third, strongly arcuate, punctures to margins, M-shaped macula imperfect; PL = 0.87–0.99 mm (mean = 0.92 mm, n = 4); PW = 1.14–1.34 mm (mean = 1.27 mm, n = 4); PL/PW = 0.68–0.75 (mean = 0.73, n = 4). Elytra: Yellow with broad suffused pale brown to fuscous markings. Pygidium: Yellow-brown. Venter: Brown. Legs: Yellowbrown; front claws not enlarged. Genitalia: Median lobe in en-face view with extended PRL with thickened sides, culminating in triangular OS, protruding nodule present, visible setae at ALM; MLW = 0.22–0.24 mm (mean = 0.23 mm, n = 4). Median lobe in lateral view with distinct ridge or keel extending entire length ( Fig. 5E ); MLL = 0.54–0.60 mm (mean = 0.58 mm, n = 4). Four males from three USA states were dissected.

Female. As in male, except L = 3.49–3.75 mm (mean = 3.62 mm, n = 4); W = 1.86–2.01 mm (mean = 1.93 mm, n = 4); L/W = 1.81–1.91 (mean = 1.87, n = 4); HW = 1.08–1.22 mm (mean = 1.14 mm, n = 4); IOD = 0.19–0.25 mm (mean = 0.22 mm, n = 4); IOD/HW = 0.17–0.21 (mean = 0.19, n = 4).

Remarks. Fall (1915), who described both species, noted that P. integratus is much like P. vigilans , speculating that additional specimens may prove them to be the same. Dissection of 32 males from Arizona, California, Texas, and Utah revealed two very similar, but distinct median lobes. The median lobes matching that of the P. vigilans holotype were decidedly shorter and narrower, with no ridge or nodule, as compared to a second cohort, which had a distinct ridge and nodule. Unfortunately, Fall’ s description of P. integratus was based upon a female, thereby eliminating the absolute confirmation of the second cohort as P.

integratus. Fall’ s personal collection contained two specimens labeled P. integratus : one male and one female. Dissection of the male revealed it to be P. vigilans .

Distribution. This species is found in the southwestern USA and northern Mexico (Map 1A). New state records were confirmed for two states, Texas and Utah, that were not reported for P. integratus by Riley et al. (2003).

Biological Notes. Specimens were collected via UV blacklight in Texas.

Specimens Examined. See Appendix 5.

Figures

Fig. 5. Pachybrachis integratus, Brewster Co., Texas. A–B) Dorsal and lateral habitus, respectively, C) Face, D) Pygidium, E–F) Median lobe of aedeagus, lateral and en-face views, respectively.

Fig. 13. Pachybrachis species, type specimens. A) P. connexus (female), B) P. integratus (female), C) P. morosus (female), D) P. haematodes (male), E) P. analis (female), F) P. marmoratus (female), G) P. desertus (male), H) P. brunneus (male), I) P. uteanus (male).