Benedictesmus ellenae Shear & Marek, 2021

Shear, William A. & Marek, Paul E., 2021, Three new genera and eighteen new species of miniature polydesmid millipedes from the northwestern United States (Diplopoda, Polydesmida, Polydesmidae), Zootaxa 4975 (1), pp. 81-126 : 116

Benedictesmus ellenae Shear & Marek , n. sp.

Figs 102–110 , 134

Types. Male holotype and male paratype from 4 mi south of Pistol River on US 101 , 42.3286 °, - 124.4219°, 200 ft asl, Curry Co., Oregon, collected 12 February 1972 by E. M. Benedict. All types deposited in CAS .

Diagnosis. The pulvillus of the gonopod is well separated from the terminal zone, a pulvillar process is absent, and the pulvillus is extended into a moderately long, membranous tube ( Fig. 105 ). The anterior marginal setal row of the collum has 18 setae ( Fig. 102 ).

Etymology. The species name recognizes the collector, Ellen M. Benedict.

Description. Male holotype. Eighteen rings. Length about 4.0 mm, greatest width 0.45 mm. Head densely setose, cuticle alveolate ( Fig. 101 ). Collum ( Fig. 102 ) with anterior marginal row of 18 setae. Anterior metazonites with three rows of setae, transitioning to four rows ( Fig. 103 ) about ring 5, setal tubercles becoming almost obsolete on midbody to posterior rings. Alveolate cuticle absent from metazonites posterior to collum. Epiproct ( Fig. 104 ) slightly swollen, short, strongly decurved, with alveolate cuticle. Anterior legs crassate, tarsi with sphaerotrichomes. Gonopod ( Figs 105, 106 , 134 ) with moderately inflated prefemorite.Acropodite short, robust. Pulvillus (p, Fig. 104 , Fig. 105 ) basal to midlength of acropodite, extended as a tube ( Fig. 106 ). Pulvillar process absent. Terminal zone (tz, Fig. 105 ) bifurcate, longer distal process flattened, curved; shorter process subtriangular. Females unknown, probably with 19 rings.

Distribution. Curry Co., Oregon.

Records: OREGON: Curry Co.: 1 mi north, 3 mi west of Brookings, 42.0708°, -124.3081°, sea level, 2 February 1972, E. M. Benedict, mm. These specimens had dried out and have been rehydrated.

Note: One of the male paratypes carried several minute nematodes attached to the head ( Figs 107, 109, 110 ) and on some of the rings ( Fig. 108 ). The nematodes, while firmly attached to the millipede’s cuticle by their tails, are probably not parasites since there is no indication that the cuticle of the millipede has been penetrated—some nematodes have glands in the tail or spinnerets that secrete adhesives. More likely, they are commensal and phoretic. The nematodes appear as Geraldius or Chambersiella spp. and their coiling may indicate that they are anhydrobiotic (J. Eisenback, per. comm.).

Figures

FIGURES 101–106. Species of Benedictesmus, n. gen. 101, Gonopods of Benedictesmus aureus, n. sp., ventral view. SEM stub WS33-6. 102–106. Benedictesmus ellenae, n. sp. 102. Head and anterior rings, dorsal view. 103. Midbody ring, dorsal view. 104. Pygidium, lateral view. 105. Gonopods in situ, lateroventral view. 106. Pulvillus of gonopod. SEM stub WS33- 13.Abbreviations: p, pulvillus; pp, pulvillar process; ppf, prefemorite pore field; tz, terminal zone.

FIGURES 107–110. Commensal nematodes on Benedictesmus ellenae, n. sp. 107. Four nematodes attached to head and collum. 108. Two nematodes attached to a metazonite. 109. Detail of nematodes attached to head. 110. Nematode attached to head, lateral view. SEM stub WS33-13.

FIGURES 133–137. Drawings of gonopods of polydesmid species. 133. Right gonopod of Benedictesmus aureus, n. sp., mesal view. 134. Right gonopod of Benedictesmus ellenae,n. sp., lateral view. 135, Right gonopod of Benedictesmus yaquina, n. sp., lateral view. Fig. 136, 137, Benedictesmus timber.n. sp. 136, Right gonopod, lateral view. 137, Tip of right gonopod, mesal view. Abbreviation: p, pulvillus.