Ochrogramma bentona
Creators: name: Marek, William A. Shear Paul E.
Publisher: name: Zenodo
Year: 2024
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Diplopoda
Chordeumatida
Caseyidae
Ochrogramma
Ochrogramma bentona

description: Ochrogramma bentona (Chamberlin, 1951)
Caseya bentona Chamberlin 1951: 2
Ochrogramma bentona — Gardner and Shelley 1989: 197.
(Fig. 13–31)
Descriptive notes. Gardner and Shelley did not report any records of Ochrogramma species north of the Columbia River, but given the wide distribution of O. bentona in western Oregon —the northern three fourths of the coastal region to just south of the river—our new records are not surprising. These records extend the distribution of the species north to the Puget Sound region.
We found little variation in the gonopods of the specimens we examined, but Gardner and Shelley (1989) illustrated a wide degree of variation in the female vulvae or cyphopods (see their Fig. 38–41), raising the possibility of more than one species being present; alternatively, the female genitalia could be quite variable within the species. Examination of the DNA of freshly collected material would answer this question.
As with males of V. irritans, O. bentona has the typical suite of caseyid modifications of the anterior legs and legpair 10 (Fig. 15–18). Legpair one shows reduced telopodites with longer, flattened setae on the postfemora and tibiae. Legpair two coxae bear long, thin, acutely pointed gonapophyses that are longer than the legpair two telopodites (ga, Fig. 15); the openings of the vasa deferentia are large and just posterior to the bases of the gonapophyses (vd, Fig. 15). In many preserved specimens the gonapophyses are carried in front of the male’s “face,” but we do not know if this is the case in life. Legpair three coxae are extended into the usual broad lobes that do not exceed the somewhat reduced telopodites (cx3, cl, Fig. 16). The setae on the tips of the lobes arise from deep sockets, have somewhat swollen bases and are variously curled and appressed to the surface of the lobe (Fig. 17). The coxae of legpair seven (cx7, Fig. 18) each have a low, flattened mediodistal lobe.
Ochrogramma bentona gonopods (Fig. 19–24) are considerably simpler than those of V. irritans, principally because the number of arborescent processes is greatly reduced; these are limited to a small area near the apex of the anterior angiocoxite as seen in anterior view (aac, Fig. 19). There appears to be a median, quadrate sternal sclerite linking more massive lateral lobes on either side, with a partial separation by a membranous region. In lateral view (Fig. 21), the anterior angiocoxite (aac) is apically sigmoidally twisted and bears on its mesoposterior surface a large, complexly branched process (Fig. 23). Arising near the base of the angiocoxite is a similar, more sparsely branched structure that is probably the flagellocoxite (f, Fig. 21). The much reduced telopodite (t, Fig. 20, 21) articulates at the lateral base of the anterior angiocoxite and is divided at its tip into several slender branches. The posterior angiocoxite (pac, Fig. 20–22) is slender, rodlike, and as with the telopodite is finely divided apically. The colpocoxite (cc, Fig. 20–22) is somewhat more robustly sclerotized than usual and in keeping with its hypothesized origin from the coxal gland of the eighth legpair is seen in posterior view (Fig. 20) to arise from a socket or pore.
Interestingly, the arborescent processes of the anterior angiocoxite have a stereotypical form (Fig. 24), each with three divisions. The most basal is a low, rounded knob with four or five “warts,” the next distal division a larger version of the most basal, and the most distal division a long, arched stem with many branches, but the branches do not end in the cuplike tips of those of V. irritans.
The ninth legs (Fig. 25, 26) are typical of caseyids, with coxae (cx9, Fig. 25) bearing mesal processes (Fig. 26) and single-articled, button-like telopodites (t9, Fig. 25). The coxae seem to have a more lightly sclerotized area on their mesal surface just proximal to the processes, but no pores could be detected. Legpair 10 (Fig. 27) is very much as in V. irritans and this form, with a double process from the trochanter (trp, Fig. 27), which is partially fused to the coxa (cx10, Fig. 27), might be a subfamilial character. The opening of the coxal gland (cg, Fig. 27) is very large and occupies much of the mesal surface of the coxa.
The female genitalia are illustrated in posterior view in Fig. 31. The outer (ov) and inner (iv) valves appear to be fused.
Ochrogramma bentona was recorded by Gardner and Shelley (1989) from the following Oregon counties: Benton, Coos, Lincoln, Polk and Washington. In addition to the new records from Washington state, we add the Oregon counties of Clackamas, Columbia and Linn.
New records
OREGON: Benton Co.: Missouri Bend Recreation Area, N44°20.68′, W123°43.17′, 229′ asl, 29 September 2004, W. Leonard, m; 1 mi on Botkin Road from SR34, N44°27.826′ W123°27.701′, 25 February 2005, W. Leonard, C. Richart, m, f; Clemens Park, Seely Creek Road, 0.3 mi from SR34, North Fork Alsea River, N44°24.55′, W123°34.07′, 400′ asl, 4 December 2005, W. Leonard, C. Richart, mm, f. Clackamas Co.: Mount Hood National Forest, Ripplebrook Campground, N45°04.801′, W132°02.542′, 1420′ asl, 26 October 2003, W. Leonard, m. Columbia Co.: Keystone Creek, Clatskanie Valley, N40°04.933′, W123°09.411′, 132 asl, 8 February 2004, W. Leonard, C. Richart, m, ff. Lincoln Co.: Along SR34 between Tidewater and Waldport, 19 November 1946, J. C. Chamberlin, m, f (FSCA). Linn Co.: Willamette National Forest, Sweet Home Road, 1 June, 3 August, 12, 27 September, 1 October 2001, J. Rykken, mm, ff. WASHINGTON: Cowlitz Co.: SR504, 2.1 mi E of Toutle, N46°20.90′, W122° 42399′, 500′ asl, 1 March 2004, W. Leonard, C. Richart, mm, ff. Grays Harbor Co.: 3 mi N on SR12 on Middle Satsop Road, N47°01.992′, W123°31.553′, 26 November 2004, W. Leonard, m; N47°18.879′, W123°33.382′, 830′ asl, 13 October 2003, W. Leonard, m. King Co.: Exit 18 on I-90, near Olallie State Park, N47°26.651′, W121°40.081′, 23 February 2004, W. Leonard, C. Richart, m. Lewis Co.: 8 mi S of Randall, 6 December 2003, W. Leonard, C. Richart, m, ff; 8.5 mi S of Randall on FS25, Gifford Pinchot National Forest, W46°26.489′, W121°59.890′, 21 December 2003, W. Leonard, mm, ff; Iron Creek Campground, 9.6 mi S of Randall on FS25, Gifford Pinchot National Forest, 950′ asl, 21 December 2003, W. Leonard, m, ff, N46°26.456′, W121°59.796′, 1050′ asl, 6 December 2003, W. Leonard, C. Richart, mm, ff; 604 Roswell Road, Centralia, N46°41.339′, W122°56.664, 240′ asl, 25 January 2004, C. Richart, W. Leonard, m; SR 508 at Bremer, N46°15.30′, W122°25.55′, 750′ asl, 6 December 2003, Q. Leonard, C. Richart, m, f; seep beside road along Cowlitz River east of Riffle Lake, N46°27.727, W122°09.763′, 650′ asl, 9 April, 2004, W. Leonard, C. Richart, m. Pacific Co.: Long Beach, 30 th Street, 0.2 from US 101, N46°19.436′, W124°03.591′, 50′ asl, 15 January 2006, W. Leonard, C. Richart, m. Pierce Co.: Sequakitchew Creek trailhead, N47.107°, W122.645°, 200–220′ asl, 28 January 2012, R. Crawford, m, f (BMUW). Thurston Co.: McAllister Springs, N47°02.946, W122°43.678, 22 February 2004, W. Leonard, m, f N47°02.837, W122°43.722, 60-120′ asl, 7 Feb 2004, W. Leonard, C. Richart, m, ff; McAllister Creek, S of Steelacoom Road, N47°03.42′, W122°42.79′, 100′ asl, 11 December 2004, W. Leonard, mm, ff; Hospital Creek, 3 mi S, 3 mi E of Vail, 12 October 2003, W. Leonard, m, at confluence with Skookumchuck River, N46°46.396′, W122°35.133′, 15 December 2003, W. Leonard, K. McAllister, m, ff; Skookumchuck River, 5 mi S, 3 mi E of Vail, 2 October 2003, W. Leonard, mm; Rainier Road, 3.6 mi NW of Military Road, Fort Lewis Military Reservation, 29 November 2003, W. Leonard, mm, ff; Priest Point Park, N47°04.47, W122°53.85′, 11 January 2004, W. Leonard, m.
description: Published as part of Marek, William A. Shear Paul E., 2024, Additions to the millipede family Caseyidae Verhoeff, 1909. III. Proposal of the new subfamily Ochrogrammatinae, new records of Vasingtona irritans (Chamberlin, 1910), established species of Ochrogramma Gardener and Shelley, 1989 a new species of Ochrogramma from Washington state, USA, pp. 1-21 in Insecta Mundi 2024 (90) on pages 8-11, DOI: 10.5281/zenodo.14662376