Pseudopolydesmus pinetorum, PINETORUM (BOLLMAN, 1888)

Sierwald, Petra, Hennen, Derek A, Zahnle, Xavier J, Ware, Stephanie & Marek, Paul E, 2019, Taxonomic synthesis of the eastern North American millipede genus Pseudopolydesmus (Diplopoda: Polydesmida: Polydesmidae), utilizing high-detail ultraviolet fluorescence imaging, Zoological Journal of the Linnean Society 187 (1), pp. 117-142 : 132-135

PSEUDOPOLYDESMUS PINETORUM ( BOLLMAN, 1888)

( FIGS 17–20 )

Polydesmus pinetorum Bollman, 1888: 3 , ♂ HT (USNM, non vidi, type lost).

Pseudopolydesmus pinetorum – Causey, 1952: 6, fig. 5 (= Po. americanus ; Po. paroicus ; Po. hubricthi ; Po. modocus ). – Chamberlin & Hoffman, 1958: 70. – [ Withrow, 1988: 72, figs 74, 80, 82, 86, 90, 106, 111, 122–128, map 4, tables 9–11.] – Hoffman, 1999: 445.

Polydesmus americanus Carl, 1902: 611 , pl. 11: fig. 37, two ♂ ST (MHNG, non vidi).

Pseudopolydesmus americanus – Attems, 1940: 140, fig. 202. – Carl, 1941: 292, figs 1–2.

Polydesmus natchitoches Chamberlin, 1942b: 10 , figs 34, 35, ♂ HT (USNM, vidi), synon. nov.

Pseudopolydesmus natchitoches – Chamberlin & Hoffman, 1958: 70. – Hoffman, 1999: 445.

Polydesmus paroicus Chamberlin, 1942b: 11 , figs 37, 38, five ♂ / ♀ ST (USNM, vidi).

Pseudopolydesmus paroicus – Chamberlin, 1943c: 18. – Chamberlin & Hoffman, 1958: 70. – Hoffman, 1999; 445.

Polydesmus hubrichti Chamberlin, 1943a: 15 , figs 1, 2, ♂ HT (USNM, vidi).

Pseudopolydesmus hubrichti – Chamberlin, 1943c: 18.

Polydesmus modocus Chamberlin, 1943b: 36 , fig. 6, ♂ HT (FMNH INS927, vidi). – Sierwald et al., 2005: 40.

Pseudopolydesmus modocus – Chamberlin, 1943c: 18.

Diagnosis

Size: Medium, with body length ranging from 13.6 to 25.6 mm and an average body length of 18.6 mm (N = 212; Withrow, 1988: 76, 199). Usually smaller than Ps. canadensis , Ps. collinus , Ps. erasus and Ps. serratus . Clearly larger than its small sympatric congeners Ps. minor and Ps. caddo .

Paranota and tergal sculpture ( Fig. 17 ): Corners of paranota forming a broad rectangle, nearer to a square than any other Pseudopolydesmus species. Leading and distal margins weakly curved compared with Ps. erasus and Ps. serratus , denticles always distinct. Trailing margin concave, strongly curved. Anterior blister row much thicker than median and posterior blister rows, which are subequal in thickness. Median blister 2 and PB2 subequal in area and much larger than MB1 and PB1. Central paranotal blisters large, occupying over two-thirds of paranotal breadth, as wide as long. Lateral blisters anteriorly widening laterad.

Gonopod ( Figs 18–20 ): Gonocoxa ventral lobe with single gonocoxal plate. Telopodite entirely arcuate and fishhook-shaped, section distal of pulvillus tightly curved. Pulvillus large, rounded, closer to terminus of acropodite than base. Processes e1, m3 absent. Process e2 lobe-like, recurved, separate from e3; process e3 very large, subtriangular to spike-shaped; process e4 small and laminate, proximal to terminal tuft of bristles ( Figs 18A , 19A , 20A ). Process m1 small, hidden at base of pulvillus; m2 small, subtriangular; m4 mediumsized, subtriangular, close to m2 ( Figs 18B , 19B , 20B ).

Type notes

Polydesmus pinetorum (♂ HT, USNM, non vidi, type lost): From Little Rock, Pulaski Co., AR, USA . Bollman (1888) mentions additional specimens from Clark, Pike and Sevier Cos in Arkansas. Apparently, Withrow examined the ♂ HT at USNM; no type material was found there (Sierwald, November 2015).

Polydesmus americanus : (two ♂ ST, MHNG, non vidi): From Texas, without further locality .

Polydesmus natchitoches (four ♂ / ♀ ST, USNM, vidi; one ♂ ST, USNM, non vidi): Chamberlin (1942b) described four ST from two miles south of Saline , collected 12 April 1936 , and one ♂ ST from four miles north of Chestnut , collected 14 April 1936. All collected by L. Hubricht. Both localities are in Natchitoches Par., LA, USA . One type lot found, from the Saline locality: labelled ‘= pinetorum ’ by Withrow, contains genitalia vial with two intact male gonopods and three or four fragmented male and female specimens, including one female with vulvae everted. Specimens sorted into three vials. Vial 1 contains one fragmented male with gonopods missing and genitalia vial containing two gonopods (most probably not from the same male). Vial 2 contains two fragmented females, one with everted vulvae. Vial 3 contains several specimen fragments. ♂ ST from Chestnut locality not found.

Polydesmus paroicus (three ♂ and two ♀ ST, USNM, vidi): From 1.5 miles north of Clay , boundary of Lincoln and Jackson Parishes, LA, USA, collected 12 April 1936 by L. Hubricht . One type lot: contains two fragmented females, two fragmented males with gonopods in situ, one male with dissected gonopods but intact body ring 7, and one genitalia vial with fragments of body ring 7 and at least one gonopod, most probably not belonging to the male in this vial.

Polydesmus hubrichti (♂ HT and 13 ♂ PT, USNM, v i d i): C h a m b e r l i n (1 9 4 3a) d e s c r i b e d ♂ H T, ♀ allotype, and approximately ten additional ♂/♀ PT from University City, St. Louis Co., MO, USA, collected 29 March 1936 by L. Hubricht . We found one type lot and two additional lots; all labelled with the nomenclaturally invalid manuscript name ‘ Polydesmus scholasticus ’ by Chamberlin, labelled ‘ P. serratus ’ by Hubricht. Type lot: labelled ‘Types’, contains ≥ 14 specimens: male labelled ‘Lectotype’ with one dissected gonopod in a genitalia vial and 13 adult males, most with intact gonopods in situ. Non-type lot 1: labelled ‘Paratype’, contains a single female collected March 1936 under logs, from 4.3 miles northwest of Glencoe Station, St. Louis Co., MO, USA. Non-type lot 2: labelled ‘Paratypes’, collected 8 March 1936, from Creve Coeur Lake Park, St. Louis Co., MO, USA, containing seven specimens belonging to three species: two males of Ps. pinetorum (both with gonopods in situ, one with a single intact gonopod), two females of Ps. pinetorum , two males of Ps. minor (gonopods intact in situ) and one female Ps. serratus (with everted vulva). Despite labelling three lots as types (for Po. scholasticus ), Chamberlin (1943a) explicitly designated only the material from University City (vial labelled ‘Types’) in the Po. hubrichti type series.

Polydesmus modocus (♂ HT, FMNH, vidi): From between Modoc and Roots, Randolph Co., IL, USA, collected 14 April 1936 by K. P. Schmidt . ♂ HT in fragments, single gonopod in genitalia vial, images are available online at https://collections-zoology. fieldmuseum.org/catalogue/955981, last accessed 25/3/2019 ( FMNH INS 927).

Distribution

Louisiana north to southern Iowa, east through Alabama and Tennessee. Most commonly collected west of the Mississippi River.

Additional specimens examined

FMNH INS 1435, 1438 , 1445 * .

Figures

Figure 17. Pseudopolydesmus pinetorum, metatergite and paranota of body ring 10. Paratype, Polydesmus hubrichti type series vial from Glencoe Station, MO, USA, adult female (USNM, ultraviolet enhancement).

Figure 18. Gonopod of Pseudopolydesmus pinetorum. Holotype, Polydesmus natchitoches, from genitalia vial (USNM). A, left gonopod, ectal view. B, left gonopod, medial view. Both images mirrored to appear as right gonopod.

Figure 19. Gonopod of Pseudopolydesmus pinetorum. Holotype, Polydesmus natchitoches, from genitalia vial (USNM, ultraviolet enhancement). A, left gonopod, ectal view. B, left gonopod, medial view. Both images mirrored to appear as right gonopod.

Figure 20. Gonopod of Pseudopolydesmus pinetorum (FMNH INS1445, scanning electron micrograph). A, left gonopod, ectal view. B, left gonopod, medial view. Both images mirrored to appear as right gonopod.