Pachybrachis deceptor Riley and Barney

Riley, Edward G. & Barney, Robert J., 2015, Definition And Revision Of The Viduatus Species- Group Of North American Pachybrachis Chevrolat (Coleoptera: Chrysomelidae: Cryptocephalinae), The Coleopterists Bulletin 69 (1), pp. 25-59 : 31-40

1. Pachybrachis deceptor Riley and Barney , new species ( Figs. 6 , 8 ; Map 1)

Pachybrachys m-nigrum: Fall 1915: 465 (misidentification, partim).

Pachybrachis m-nigrum: Balsbaugh and Hays 1972: 38 (misidentification); Downie and Arnett 1996: 1318 (misidentification, partim).

Holotype. Male , labeled “KY: LaRue Co. / Thompson Creek Barrens / 15 June 2004 / R. J. Barney [printed, black on white] // [circular blue disc signifying dissection by RJB] // Pachybrachis / sp. EGR # 71 /? m-nigrum Melsh. / Det. E. G. Riley, 2005 [printed, black on white paper]” // HOLO- TYPE / Pachybrachis / deceptor / Riley & Barney [printed black on red].” Deposited in MCZ. The specimen is point-mounted and dissected, with abdomen and genitalia affixed to the point. It is in excellent condition with all appendages intact.

Paratypes. 196♂♂, 164♀♀ (Appendix 3).

Description. Male. Length 2.49–3.03 mm (mean = 2.79 mm, n = 10); width across humeri 1.34–1.64 mm (mean = 1.50 mm, n = 10); L/ W 1.81 –1.91 (mean = 1.87, n = 10). Head: As wide as thoracic apex, width 0.86–1.06 mm (mean = 0.98 mm, n =10); eyes not bulging laterad, upper lobes widely separated, IOD 0.37–0.48 mm (mean = 0.43 mm, n = 10), IOD/HW 0.42–0.46 (mean = 0.44, n =10); face black with spot adjacent to upper lobe of eye, median spot on lower frons, and area near antennal base yellow; frons flat, closely, distinctly, and evenly punctate; surface between punctures dull; antenna long, attaining elytral declivity. Pronotum: Length 0.76–1.09 mm (mean = 0.87, n = 10), greatest width across basal third 1.14–1.41 mm (mean = 1.28 mm, n = 10), anterior width slightly less than basal width, lateral margin arcuate basally, from there to anterior angle straight to vaguely emarginate; PL/PW 0.62–0.77 (mean = 0.68, n = 10); yellow with heavy, black, M-shaped macula that is often so strongly developed that pronotum appears black with 2 elongate basal spots, narrow oval median spot, lateral margins, and extreme apical edge yellow; disc convex, little flattened before base,

10) P. trinotatus ; 11) P. pulvinatus .

Map 1. Distribution of Pachybrachis species based on specimens examined. P. m-nigrum (circles); P. deceptor

(diamonds).

13–14) P. pulvinatus .

moderately, evenly, closely punctate, punctures dense in black area, less dense in yellow areas, especially near lateral margin; scutellum black, or rarely partially yellowish. Elytra: Black with most of apical declivity yellow and somewhat variable patch-work pattern of yellow maculae ( Fig. 6 ); punctation of elytral disc coarser than on pronotum, confused in baso-sutural region, semi-regular laterally where some punctures form short serial arrangements; striae weak and incomplete; median-sutural yellow spot (shield of Fall) often raised and impunctate; surface between punctures dull. Pygidium: Black with 2 yellow maculae nearly joined to lateral margin; finely punctate, weakly convex. Venter: Black, last ventrite with small lateral yellow spot. Legs: Black and yellow; femora black in basal half, tibiae black in distal half. Genitalia: Median lobe in en-face view with shaft widest subapically ( Fig. 8 ), lateral margins evenly, broadly, and rather distinctly emarginate behind; postorificial length short, ca. as long as marginal space is wide; lateral basal plates well-pigmented, median basal plate weakly pigmented, membranous; en-face outline with apicolateral margin abruptly, broadly rounded; distal en-face outline oblique, weakly and broadly emarginate before poorly defined nodule. Beard conspicuous, consisting of apicolateral wisp on each side; setae of wisp dense, moderately long, weakly graded in length with longest setae medial in serial position, curved mesad. Ventral surface inflated, without keel, with a continuous bulge from base to near terminus, longitudinally fluted basally and for most of length; distal profile strongly narrowed, slightly deflexed.

Female. As in male, except length 2.87–3.38 mm (mean = 3.26 mm, n = 10); width across humeri 1.63–1.86 mm (mean = 1.77 mm, n = 10); head width 1.02–1.20 mm (mean = 1.13 mm, n = 10); interocular distance 0.47–0.60 mm (mean = 0.55 mm, n = 10); IOD/HW 0.46–0.50 (mean = 0.48, n = 10); antennae attaining elytral mid-length.

Etymology. Latin, meaning the deceiver, a fitting reference for a cryptic species that has tricked previous workers by masquerading under one of our best-known names.

Remarks. Most specimens received on loan were consistently misidentified as P. m-nigrum , and, indeed, this new species is externally indistinguishable from that species. On average, however, there is a tendency for the overall size to be a little larger and for the yellow markings on the body and legs to be more reduced; however, these differences are not definitive. The gross shape of the male median lobe is definitive and will easily separate this species from P. m-nigrum , the only similarly patterned member of the viduatus species-group. In en-face view, the median lobe is broadly constricted before the apicolateral angle and the beard is a conspicuous wisp. Collecting event data that we cite for the examined specimens of P. deceptor and P. m-nigrum (Appendices 3 and 5, respectively) include at least one dissected male; events represented only by females were assigned to this species only if there were other confirmed collecting events from the same location or if all

16) P. chester , holotype; 17) P. kentuckyensis , holotype; 18) P. viduatus .

other specimens collected in the state were of one species (Alabama, Iowa, Kansas, Louisiana, Mississippi, Oklahoma, and Texas). Unidentified females from transitional states (Illinois, Indiana, Kentucky, Missouri, North Carolina, and Tennessee) are listed separately (Appendix 10).

Distribution. Found from northern Illinois and southeastern Iowa, south to western North Carolina, northwestern Louisiana, and southeastern Kansas (Map 1). This species is broadly sympatric with P. m-nigrum from western North Carolina west to the Chicago area of northern Illinois and southeastern Missouri. There is one instance where P. m-nigrum and P. deceptor were apparently taken in the same collecting event (specimens with identical labels) at Hessville, Indiana, on 4 July 1908.

Biological Notes. Both of us have confirmed the association of adults with Hypericum spp. through repeated collections from this plant (collectively from Illinois, Kentucky, Oklahoma, and Tennessee). In Kentucky, this species has been taken on Hypericum dolabriforme Vent. (Barney and Hall 2011 — as P. m-nigrum ). It is fairly common on Hypericum sphaerocarpum Michx. growing in glade communities in central Tennessee. According to the Kentucky State Nature Preserves Commission, the type locality, Thompson Creek Glades State Nature Preserve, is a very high quality, dry hill glade developed on thinbedded Salem limestone. The LeFlore County, Oklahoma specimens were taken from an unidentified Hypericum species growing in a rocky, partial open-canopy, oak-hickory-pine woodland.

Specimens Examined. See Appendix 3.

2. Pachybrachis m-nigrum ( Melsheimer, 1847) ( Figs. 4, 5 , 9 ; Map 1)

Pachybrachis M. Nigrum Dejean 1836: 421 (catalogue) [nomen nudum].

Cryptocephalus M. Nigrum Melsheimer 1847: 170 (original description).

Pachybrachis m-nigrum: Haldeman 1849: 261 (taxonomy); Wilcox 1975: 30 (catalogue); Downie and Arnett 1996:1318 (taxonomy, partim); Riley et al. 2003: 160 (catalogue); Clark et al. 2004: 159 (plant associations); Ciegler 2007: 180 (taxonomy); Barney et al. 2013: 120 , habitus 8, fig. 6c (taxonomy).

Pachybrachys intricatus Suffrian 1852: 180 [name attributed to Knoch] (original description); LeConte 1880: 207 [“ m-nigrum Haldeman ” in synonymy] (taxonomy); Henshaw 1885: 107 (catalogue); Fall 1915: 466, 486 [placed in synonymy with P. m-nigrum Melsheimer ] (taxonomy, catalogue).

Pachybrachys M. nigrum: Suffrian 1852: 183 [in synonymy under P. intricatus Knoch , attributed to Haldeman]; Suffrian 1852: 209 [in synonymy under P. picturatus Germar , attributed to Melsheimer]; LeConte 1880: 209 (catalogue, as questionable var. of P. picturatus ).

Pachybrachis M-nigrum : Melsheimer, 1853: 127 (catalogue).

Pachybrachys M-nigrum : Gemminger and Harold 1874: 3354 [in synonymy under P. intricatus Suffrian and attributed to Haldeman] (catalogue); Gemminger and Harold 1874: 3356 [in synonymy under P. picturatus Germar and attributed to Melsheimer] (catalogue); Henshaw 1885: 107 [in synonymy under P. picturatus Germar and attributed to Melsheimer] (catalogue); Clavareau 1913: 100 [attributed to Haldeman, as synonym of P. intricatus Suffrian ] (catalogue); Clavareau 1913: 103 [attributed to Melsheimer, as synonym of P. picturatus Germar ] (catalogue).

Pachybrachys m-nigrum: Blatchley 1910: 1128 (taxonomy); Fall 1915: 465, 486 (taxonomy partim, catalogue); Leng 1920: 290 (catalogue); Wilcox 1954: 393 (taxonomy).

Type Material. Pachybrachis m-nigrum . Lectotype, designated herein. Fall (1915) did not explicitly mention Melsheimer’ s type(s). A male ( Fig. 4 ) from the Melsheimer Collection ( MCZ) is here designated as lectotype, labeled: “Melsh. / Mnigrum [printed/hand-inked, white paper] // [torn piece of red paper] // m-nigrum [handinked, white paper, lined border] // LECTOTYPE / Cryptocephalus / m-nigrum Melsheimer 1847 /desig. Riley & Barney, 2014 [printed black on red].” At least two additional specimens in the Melsheimer Collection, one male and one female labeled “[blue round disc] // Ziegler. [printed, beige paper] // Mnigrum / Mels. / Pa. [hand-inked, beige paper, lined border]”, and one female from the LeConte Collection ( MCZ) labeled “[pink round disc] // P. M-nigrum Mels. / Hald. / intricatus Suffr. [handinked, white paper]” are likely syntypes ( Hagen 1884) and are herein designated and labeled as paralectotypes.

Pachybrachys intricatus . Lectotype designated herein. Suffrian (1852) had multiple specimens since he indicated several collection sources. Our examination of four syntypes [2♂♂ 2♀♀, MNHUB] has confirmed the synonymy proposed by Fall (1915). A male ( Fig. 5 ) is here designated as lectotype, and it is labeled “24079 [printed, white paper] // Pachybrachys / intricatus Kn. Suffr / M. nigrum Hald. [hand-inked, white paper] // intricatus / N (?) / Pensylv. Knoch [hand-inked, green paper, lined border] // SYNTYPUS / Pachybrachis / intricatus Suffrian, 1852 / labeled by MNHUB 2013 [printed, red paper] / LECTOTYPE / Pachybrachys / intricatus Suffrian 1852 / desig. Riley & Barney [printed black on red].” This specimen is in good condition and is not dissected. The remaining three MNHUB specimens are conspecific with the lectotype and similarly labeled, and they are here designated and labeled as paralectotypes. The MLUH has four conspecific specimens [2♂♂ 2♀♀] in the Suffrian Collection, each labeled with a very small label with a hand-inked number in red ink. These are also here considered syntypes and are labeled as paralectotypes.

Redescription. M a l e: A s d e s c r i b e d f o r P. deceptor , except dorsal color pattern often with yellow color dominant over black ( Fig. 4 ). Length 2.46–2.64 mm (mean = 2.56 mm, n = 10); width across humeri 1.30–1.48 mm (mean = 1.40 mm, n = 10); L/ W 1.74 –1.90 (mean = 1.83, n = 10). Head: Width 0.85–0.92 mm (mean = 0.88 mm, n = 10); eyes widely separated, IOD 0.36–0.40 mm (mean = 0.39 mm, n = 10), IOD/HW 0.42–0.46 (mean = 0.44, n = 10). Pronotum: Length 0.80–0.91 mm (mean = 0.86 mm, n = 10), width 1.14–1.25 mm (mean = 1.19 mm, n = 10), PL/PW 0.67–0.76 (mean = 0.72, n = 10). Genitalia: Median lobe in en-face view of near equal width throughout, side margins of shaft not tapered behind apicolateral curvature ( Fig. 9 ); length of postorificial space moderately long, ca. 3 times width of marginal space; lateral basal endophallic plates well-pigmented, median plate nearly equally pigmented, broad basally, narrowed distally; en-face outline with apicolateral margin evenly, broadly rounded, continuous with distal en-face outline, nearly straight to terminus; nodule absent. Beard inconspicuous with tips of longest setae visible in en-face view, consisting of apicolateral sparse patch; setae short, straight, graded with longest setae prebasal in serial position. Ventral surface simple, not swollen or otherwise modified. Distal profile with moderate angle at point of apicolateral curvature, from there uniformly narrowed to terminus, weakly reflexed distally.

Female. As described for P. deceptor , except length 2.77–3.16 mm (mean = 2.91 mm, n = 10); width across humeri 1.49–1.77 mm (mean = 1.63 mm, n = 10); head width 0.95–1.11 mm (mean = 1.02 mm, n = 10); interocular distance 0.43–0.53 mm (mean = 0.49 mm, n = 10); IOD/ HW 0.45–0.51 (mean = 0.48, n = 10).

Remarks. This species was often found misidentified in collections as P. intricatus or P. picturatus . It cannot be reliably distinguished from P. deceptor except by examination of the male genitalia. On average, however, there is a tendency for the overall size to be smaller and for the yellow markings on the body and legs to be more extensive, but these differences are not definitive. The male median lobe is distinctive and definitive and will easily separate this species from P. deceptor , the only similarly patterned member of the viduatus species-group. Collecting event data that we cite for the examined specimens of P. m-nigrum include at least one dissected male for each event. Those events represented by females only were identified to species only if there were other confirmed events from the same location or if all other confirmed specimens collected in the state were of a single species (Connecticut, District of Columbia, Delaware, Florida, Georgia, Maine, Maryland, Mssachusetts, New Hampshire, New Jersey, New York, Ohio, Pennsylvania, Rhode Island, South Carolina, Virginia, and West Virginia). Unassociated females from transitional states (Illinois, Indiana, Kentucky, Missouri, North Carolina, and Tennessee) are listed separately (Appendix 10).

Interestingly, the species-group name m-nigrum did not appear in F. V. Melsheimer’ s catalogue of American insects (1806); rather, it first appeared in the catalogue of the Coleoptera collection of the French coleopterist Pierre Francois Marie Auguste Dejean ( Dejean 1836), where it was registered as from “Am. bor.” F. E. Melsheimer (1847) validated the species-group name through description and stated “This species may prove to be a variety of the viduatus, Fabr. ” This latter statement could be the source of the subsequent confusion about the identity of the species.

Distribution. This species ranges from extreme southern Ontario, Québec, and Maine south to central South Carolina west to the Chicago area of northern Illinois and southeastern Missouri (Map 1). It is broadly sympatric with P. deceptor from western North Carolina to southeastern Missouri and the Chicago area of northern Illinois. The record from Monroe County, Florida seems far out of range for this species and is here considered doubtful.

Biological Notes. There are surprisingly few plant association records for this widespread and common species ( Clark et al. 2004). Five specimens in the MCZ are labeled as “numerous on Lysimachia stricta ,” a plant that is otherwise known as L. terrestris var. ornata (E. L. Rand and Redfield) Fernald (Primulaceae) or yellow loosestrife. Both P. m-nigrum and P. deceptor were taken in the same collecting event (identical labels) in Hessville, Indiana on 4 July 1908.

Specimens Examined. See Appendix 5.

3. Pachybrachis pulvinatus Suffrian, 1852 ( Figs. 11 , 13–14 ; Map 2)

Pachybrachis pulvinatus Sturm 1843: 301 (catalogue) [nomen nudum, name attributed to Boeber]; Balsbaugh and Hays 1972: 39 (taxonomy); Wilcox 1975: 31 (catalogue); Downie and Arnett 1996: 1319 (taxonomy); Riley et al. 2003: Map 2. Distribution of Pachybrachis species based on specimens examined. P. trinotatus (diamonds); P. pulvinatus

(circles).

162 (catalogue); Clark et al. 2004: 161 (plant associations); Ciegler 2007: 181 (taxonomy).

Pachybrachys pulvinatus Suffrian 1852: 151 [attributed to Boeber] (original description); Gemminger and Harold 1874: 3356 (catalogue); LeConte 1880: 209 (catalogue); Henshaw 1885: 107 (catalogue); Clavareau 1913: 104 (catalogue); Fall 1915: 467, 486 (taxonomy, catalogue), Leng 1920: 290 (catalogue); Wilcox 1954: 393 (taxonomy).

Type Material. Whereabouts undetermined. Suffrian (1852) had multiple specimens since he indicated multiple collection sources. He described P. pulvinatus as black with yellow antennae, white spots on the head, a pale spot on the leg tips, and the pronotum and elytra mottled reddish, densely and coarsely punctate. The type location was given as “…östlichen Landschaften, namentlich in Pennsylvanien” [… in the eastern landscapes, especially in Pennsylvania]. A request to MNHUB did not reveal syntype material, and a request to MLUH returned one specimen that is not consistent with the original description. An apparent syntype in the Natural History Museum, London (originally from the Chevrolat Collection) is a male Pachybrachis confusus Bowditch .

Fall (1915) reported that he examined a Suffrian type or co-type that was originally sent to Bowditch from Halle. The MCZ collection houses both the Fall and Bowditch Collections, but none of the specimens in those collections are candidates for original Suffrian syntypes. Here we accept Fall’ s concept for P. pulvinatus and suspect original syntype material that is consistent with Fall’ s interpretation exists somewhere in European collections. Although Suffrian specifically mentioned Pennsylvania , we have not seen specimens of P. pulvinatus from Pennsylvania.

Description. Male: Length 2.70–3.04 mm (mean = 2.90 mm, n = 10); width across humeri 1.46–1.67 mm (mean = 1.59 mm, n = 10); L/ W 1.77 –1.90 (mean = 1.83, n = 10). Head: As wide as thoracic apex, width 1.01–1.12 mm (mean = 1.07 mm); eyes little bulging laterad, upper lobes widely separated, IOD 0.38–0.49 mm (mean = 0.45 mm, n = 10), IOD/HW 0.37–0.44 (mean = 0.41, n = 10); face black with 2 yellow to orange maculae between upper lobe of eyes; closely punctate; antennae reddish orange, surpassing elytral apex. Pronotum: Length 1.23–1.41 mm (mean = 1.33 mm, n = 10), width 0.98–1.12 mm (mean = 1.05 mm, n = 10), anterior width slightly less than basal width, lateral margin arcuate basally, from there to anterior angle straight to vaguely emarginate; PL/PW 0.71–0.82 (mean = 0.78, n = 10); varying from almost entirely black with small, median subapical macula with smaller macula on each side near anterior margin, to predominately yellow-orange with weakly defined, black, M-shaped macula, M-shaped mark sometimes reduced to spots; punctation uniform and dense, distinct to lateral bead; surface between punctation dull; scutellum black. Elytra: Black, usually with basal edge narrowly yellow-orange, ranging to disc with extensive yellow to orange areas, especially basally ( Fig. 13 ); punctation dense, slightly more coarse than on pronotum, generally confused throughout, without impressed striae; each elytron usually with vestige of weakly elevated costa extending from humerus to elytral midlength; surface between punctation dull. Pygidium: Black, evenly and finely punctate, weakly convex. Venter: Black. Legs: Black, profemur with submedian and meso- and metafemora with apical pale spot. Genitalia: Median lobe in en-face view with shaft widest subapically, side margins of shaft slightly tapered inward behind apicolateral curvature ( Fig. 11 ); orificial space with side following marginal contour of shaft; length of postorificial space moderately long, ca. 4 times width of marginal space; lateral basal endophallic plates wellpigmented; median plate nearly equally pigmented, broad basally, narrowed distally. En-face outline with apicolateral margin broadly, rather sharply rounded; distal en-face margin straight, oblique to terminus; nodule absent. Beard a conspicuous wisp; setae of wisp in broad, elongate patch occupying most of apicolateral margin, dense, moderately long, weakly graded in length with longest medial in serial position, curved mesad. Ventral surface simple, not swollen or otherwise modified. Distal profile uniformly narrowed to terminus.

Female. As in male, except length 3.13–3.63 mm (mean = 3.33 mm, n = 10); width across humeri 1.65–2.00 mm (mean = 1.82 mm, n = 10); head width 1.10–1.32 mm (mean = 1.22 mm, n = 10); IOD 0.48–0.68 mm (mean = 0.59 mm, n = 10); IOD/HW 0.44–0.54 (mean = 0.49, n = 10); pale spots above the eyes reduced to absent; antenna nearly attaining elytral declivity; pygidium nearly flat.

Remarks. Pachybrachis pulvinatus was often misidentified as P. trinotatus in collections we studied, and misidentified specimens were found in the Fall, Horn, and LeConte Collections. Specimens misidentified as P. confusus were found in the Blatchley Collection. Color patterns on the pronotum and elytra are extremely variable in this species, with variations often within a series from the same collecting event. The pronotum ranges from entirely black to red with a trinotatus -like, black, M-shaped mark, rarely broken into separate spots. The light yellow to cream-colored spot on the femur of both sexes is a simple and reliable external character that will distinguish this species from P. trinotatus , which has entirely black femora.

Distribution. Found on the Atlantic coastal plain from eastern Louisiana to Florida to North Carolina, with the northernmost, and somewhat disjunct record, in southern New Jersey (Map 2). It appears to displace P. trinotatus on the southeastern coastal plain.

Biological Notes. There are no definitive plant associations known to us (also see, Clark et al. 2004). Specific plants are not reported on the label data seen, although the habitats of “longleaf pineturkey oak burn zone”, “flatwoods”, and “boggy field” are recorded. One of us (EGR) has taken a series (Georgetown County, South Carolina) by sweeping a wet roadside ditch that included Hypericum , but a definitive association was not confirmed.

Specimens Examined. See Appendix 7.

4. Pachybrachis trinotatus ( Melsheimer, 1847) ( Figs. 10 , 12 ; Map 2)

Cryptocephalus trinotatus F. V. Melsheimer 1806: 23 (catalogue) [nomen nudum]; F. E. Melsheimer 1847: 170 (original description).

Pachybrachys trinotatus: Suffrian 1852: 164 (taxonomy); Gemminger and Harold 1874: 3357 (catalogue); LeConte 1880: 207 (taxonomy); Henshaw 1885: 107 (catalogue); Blatchley 1910: 1128 (taxonomy); Clavareau 1913: 108 (catalogue); Fall 1915: 466, 486 (taxonomy, catalogue); Leng 1920: 290 (catalogue); Wilcox 1954: 393 (taxonomy).

Pachybrachis trinotatus: Haldeman 1849: 260 (taxonomy); F. E. Melsheimer 1853: 126 (catalogue); Balsbaugh and Hays 1972: 38, fig. 22 (taxonomy); Wilcox 1975: 32 (catalogue); Downie and Arnett 1996: 1319 (taxonomy); Riley et al. 2003: 164 (catalogue); Clark et al. 2004: 162 (plant associations); Ciegler 2007: 182 (taxonomy); Barney et al. 2013: 134 , habitus 17 (taxonomy).

Type Material. Lectotype, here designated. Melsheimer (1847) cited Pennsylvania as the geographic source for his species but gave no indication of how many specimens he had before him. Fall (1915) did not explicitly mention Melsheimer’ s type material. A male specimen from the Melsheimer Collection ( MCZ) is here designated as lectotype, and it is labeled “Melsh. / trinotatus [printed and hand-inked, white paper] // [torn piece of red paper] // trinotatus [handinked, white paper, lined border] // Cryptocephalus / trinotatus Melsheimer 1847 /desig. Riley & Barney [printed black on red].” A female from the Melsheimer Collection labeled “[blue-colored round disk] / Ziegler. [printed, beige paper] // 3nota – / ta M. / Pa. [hand-written, beige paper, lined border]” and another female specimen from the LeConte Collection ( MCZ) labeled “[pink colored round disk] // P. trinotatus / Mels. [hand-inked, white paper]” are likely syntypes ( Hagen 1884) and are herein designated and labeled as paralectotypes.

Redescription. Male: Length 2.96–3.56 mm (mean = 3.20 mm, n = 10); width across humeri 1.66–1.97 mm (mean = 1.80 mm, n = 10); L/ W 1.80 –1.89 (mean = 1.83, n = 10). Head: As wide as thoracic apex, 1.05–1.16 mm (mean = 1.11 mm, n = 10); eyes not bulging laterad, upper lobes widely separated, IOD 0.48–0.58 mm (mean = 0.52 mm, n = 10); IOD/HW 0.41–0.50 (mean = 0.46, n = 10); face black with red-orange spot adjacent to upper lobe of eye, sometimes more extensively marked; frons flat, closely and evenly punctate; surface between punctures dull; antenna black, long, reaching but not surpassing elytral declivity. Pronotum: Length 1.44–1.69 mm (mean = 1.54 mm, n = 10), width 0.99–1.26 mm (mean = 1.10 mm, n = 10), anterior width slightly less than basal width, lateral margin arcuate basally, from there to anterior angle nearly straight; PL/PW 0.67–0.74 (mean = 0.71, n = 10); red to redorange with black, M-shaped macula broad, complete, sharply defined, attaining base of pronotum; disc convex, little flattened before base, closely punctate, punctation dense in black areas, more sparsely placed in red-orange areas, including margins; surface between punctures dull; scutellum black. Elytra: Usually entirely black, rarely basal edge with small red-orange spots, very rarely redorange coloration more extensive; punctation dense, more coarse than that on pronotum, generally confused throughout, without impressed striae; each elytron sometimes with vestige of 1 or 2 weakly elevated discal costae extending from base to declivity; surface between punctures dull. Pygidium: Black, uniformly punctate, weakly convex. Venter: Black. Legs: Entirely black. Genitalia: Median lobe in en-face view of near equal width throughout, side margins of shaft not tapered behind apicolateral curvature ( Fig. 10 ); orificial space with side following marginal contour of shaft; length of postorificial space moderate, ca. 2 times width of marginal spaces; lateral base of endophallic plates well-pigmented; median basal plate weakly pigmented, broad basally, narrowed distally. En-face outline with apicolateral margin broadly and evenly rounded; distal en-face outline oblique, weakly emarginate before terminus; nodule poorly defined. Beard consisting of wisp on each site, occupying part of apicolateral margin; setae dense, moderate in length, graded in length with longest setae subbasal in position, weakly curved mesad. Ventral surface simple, not swollen or otherwise modified. Distal profile uniformly narrowed to terminus.

Female. As in male except length 3.40–3.86 mm (mean = 3.62 mm, n = 10); width across humeri 1.93–2.26 mm (mean = 2.06 mm, n = 10); head width 1.17–1.33 mm (mean = 1.25 mm, n = 10); IOD 0.54–0.69 mm (mean = 0.62 mm, n = 10); IOD/HW 0.45–0.52 (mean = 0.49, n = 10); antenna reaching to distal fourth of elytron, not attaining declivity; pygidium nearly flat.

Remarks. The viduatus species-group characters, together with the normally all-black elytra, the pronotum with reddish maculation, and the all-black legs, will distinguish this species from all other members of the group. It is most likely to be confused with the similar P. pulvinatus that can be consistently distinguished by having a pale spot near the femoral apex, pale antennae, and narrower build. Pachybrachis trinotatus is the largest member of the viduatus species-group. Normally, the elytra and body beneath are entirely black; however, two series from South Carolina, one collected at Jocassee and one collected at Clemson College, have extreme color variations. Fall attached a label to a female from the Jocassee series which reads “ Pachybrachys trinotatus var.-, Det: Fall.” The Jocassee series also contains two males with normal coloration. There are also rare examples of specimens with very minor spots of pale color from other states (North Carolina, Tennessee, Missouri, Kentucky, Ohio, and Pennsylvania), but invariably they are isolated examples, often in series of normal-colored black specimens.

Distribution. This species occupies most of the eastern United States and Canada, from southern Ontario and Québec west to southern Minnesota and Kansas, south to eastern Oklahoma, Georgia, the Florida panhandle, and North Carolina (Map 2). It is sympatric with P. pulvinatus from Mississippi to South Carolina but does not seem to be as common in the southern portions of its range, especially on the coastal plain where it appears to be displaced by this species.

Biological Notes. Clark et al. (2004) cited several reports of this species’ association with Baptisia tinctoria (L.) R. Br. ( Fabaceae ) and Ceanothus americanus L. ( Rhamnaceae ). In Kentucky, P. trinotatus was repeatedly captured on Hypericum punctatum Lam. (Barney and Hall 2011) , and several adults readily fed on this plant under laboratory conditions. There is a label reference for one female on Pycnanthemum Michx. (Lamiaceae) and for one male on sumac ( Anacardiaceae ). The assembled specimen data indicate that this species is frequently encountered by collectors, but not in large numbers.

Specimens Examined. See Appendix 8.

Figures

Figs. 4–7. Pachybrachis species, dorsal and lateral habitus, face, and pygidium. 4) P. m-nigrum, lectotype;

Figs. 8–11. Pachybrachis species, median lobe, en-face and lateral views. 8) P. deceptor; 9) P. m-nigrum;

Figs. 12–14. Pachybrachis species, dorsal and lateral habitus, face, and pygidium. 12) P. trinotatus; lectotype;