Snoqualmia idaho Shear, 2012

Shear, William A., 2012, Snoqualmia, a new polydesmid milliped genus from the northwestern United States, with a description of two new species (Diplopoda, Polydesmida, Polydesmidae), Insecta Mundi 2012 (238), pp. 1-13 : 10-12

Snoqualmia idaho Shear , new species

( Figures 9-18, 21, 22)

Types: Male holotype and female paratype from OHara Bar Campground, Nez Perce National Forest, along Selway River Road, 7 mi SE of State Route 12, 7 mi S of Lowell, Idaho Co., Idaho, collected 16 April 2004 by W. Leonard, deposited in Virginia Museum of Natural History.

Diagnosis. Adults are about twice as long as those of S. snoqualmie , with far more complex gonopods.

Etymology. The species epithet is a noun in apposition, referring to the state of Idaho.

Description. Male. Length, 7.5 mm, width 0.78 mm. Antennae short, clavate, sixth segment enlarged, with accessory sensory areas distal. Head and collum ( Fig. 9) subequal in width, proximal part of cranium with alveolate sculpture; collum transversely oval, with anterior marginal row of 18-20 acute setae, additional setae scattered. Typical midbody segment ( Fig. 14 ) with low, toothed, horizontal paranota slightly extended anteriorly, with 3 rows of acute setae set on low swellings, anterior row with 14-16 setae, middle row with 16-18, posterior row with 14-16. Pygidium ( Fig. 11, 12) rounded, with about 16 scattered acute setae, pygidial process prominent, with alveolate sculpture and four spinnerets, slightly swollen distally, somewhat decurved in lateral view.

All legs markedly more crassate than those of female, femora swollen; pregonopodal legs more so than others ( Fig. 10). Gonopods (Fig. 13, 15-18, 21, 22) with hemispherical coxae filling gonostome and tightly appressed in midline, extending from gonostome. Prefemur relatively small, transversely articulated with coxa, then parallel to body axis. Attachment of acropodite narrowed, low triangular process near origin. Acropodite shaft with broad, curved, toothed lamella, distal to this, split into strongly decurved alate process and distal zone, alate process with both coarse and fine marginal teeth. Distal zone extremely complex with many acute processes and branched cuticular setulae. Pulvillus at end of elongate process, subtended at tip of process by long, curved spine, tip of distal zone acute, curved mesally.

Female. Length, 7.0 mm, width 0.72 mm, nonsexual characters as in male, but more slender, legs not crassate. Third sternum with bifurcate medial knob.

Distribution. Known definitively only from the type locality.

Notes. This species was first detected by Withrow and named in his unpublished 1988 thesis as Idahodesmus dentatus, the type locality of which was given as U. S. Forest Service Campground, 1.5 mi E of Harvard, Latah Co., Idaho. A holotype was supposedly deposited in the United States National Museum of Natural History (USNM), and two male paratypes in the North Carolina Museum of Natural History (NCSM). Neither museum ever received these specimens. Simonsen (1990) and Golovatch (1991) cited this taxon as if it had actually been published, but Shelley (1996b) pointed out that it clearly had not been. Later, Shelley (1997) attempted to solve a persistant polydesmid puzzle, the identity of Brachydesmus hastingsus (Chamberlin) 1941 , an enigmatic species described from the Hastings Reservation in Monterey Co., California. The type vial (USNM) of B. hastingsus contained three males, whereas Chamberlin (1941) had clearly stated that the holotype male was the only specimen. Two of the males in the vial were specimens we now know are referable to Snoqualmia idaho , the other probably the actual holotype of B. hastingsus , but according to Shelley, bearing little or no resemblance to the gonopod drawing provided by Chamberlin (1941). Not knowing anything about the range of Idahodesmus dentatus or possible relatives, Shelley was reluctant to decide which if any specimen was actually B. hastingsus . He concluded that a previous worker carelessly mixed specimens and destroyed the integrity of the type sample and that it was now impossible to determine the identity of B. hastingsus from the holotype. It seems reasonable to conclude that the previous worker was Withrow, who in studying North American polydesmids would have borrowed the type material of B. hastingsus , though he does not refer to it in his thesis. I would speculate that the two males of S. idaho that are now in the type vial of B. hastingsus were those destined for the North Carolina Museum of Natural History as paratypes of Idahodesmus dentatus, and that they were placed in the wrong vial. In any case, the record cited in the thesis provides a second locality for the species.

As with S. snoqualmie , the specimens were collected from deciduous leaf litter (red alder, bigleaf maple, deer fern) in a forest dominated by western redcedar and Douglas fir.

Figures

Figures 14-18. Snoqualmia idaho, n. sp. 14) Nonporiferous midbody segment, dorsal view. 15) Gonopods, lateral view from left side. 16) Left gonopod, posterioventral view. 17) Gonopods, anterior view. 18) Gonopod pulvillus, lateral view.