Neduba cascadia Cole, Weissman, & Lightfoot, 2021

Cole, Jeffrey A., Weissman, David B., Lightfoot, David C., Ueshima, Norihiro, Warchałowska-Śliwa, Elżbieta, Maryańska-Nadachowska, Anna & Chatfield-Taylor, Will, 2021, A revision of the shield-back katydid genus Neduba (Orthoptera: Tettigoniidae: Tettigoniinae: Nedubini), Zootaxa 4910 (1), pp. 1-92 : 42-44

Neduba cascadia Cole, Weissman, & Lightfoot , sp. n.

Fig. 9 (distribution), Fig. 17 (male and female habitus, calling song, male and female terminalia, karyotype), Plate 1 F–H (live habitus), Plate 4H (male calling song), Plate 7E (male ventral sclerite), Plate 11H (female subgenital plate).

Common name. Cascade Shieldback.

History of recognition. None.

Type material. HOLOTYPE MALE: USA, OR, Jackson Co., Wildcat Campground , Hyatt Lake Complex , Cascade-Siskiyou National Monument, 42.18283N, 122.44775W, 1531 m, 27-29-VII-2016, JA Cole, JAC000002023 [specimen barcode], DNA218 [genomic], SING0616 [DNA extraction], JCR160727_02 [recording], 125 [teeth], 3.7 [mm stridulatory file length], tegmen in gelcap below specimen, deposited in CAS, Entomology type #19708.

PARATYPES (n = 12): 5♁, same data as holotype, LACM ; 4♁, same data as holotype, CAS ; 1♁, same data as holotype, JAC; 1♀ , same data as holotype except 28-VIII-2019, DB Weissman & DC Lightfoot, CAS; 1♀ , Woodruff Meadow , 30 mi. SW Crater L., 42.885125N, 122.509206W, 6-VIII-1960, JR Helfer, CAS .

Measurements. (mm, ♁n = 7, ♀ n = 1) Hind femur ♁18.05–18.95 ♀ 19.91, pronotum total length ♁9.20–9.81, ♀ 8.85, prozona length ♁3.01–4.65, ♀ 4.55, metazona dorsal length ♁5.10–6.80, ♀ 4.30, pronotum constriction width ♁2.07–2.30, ♀ 2.55, metazona dorsal width ♁6.50–7.25, ♀ 6.49, head width ♁4.10–4.68, ♀ 5.02, ovipositor length ♀ 16.00.

Distribution. Southern Cascade and Siskiyou mountain ranges of southern Oregon.

Habitat. Understory and edges of coniferous forest.

Seasonal occurrence. Scant records are from mid-July through late August. Adult activity probably lasts from midsummer through fall until first frosts.

Stridulatory file. (n = 4) length 3.4–3.7 mm, 125–133 teeth, tooth density 36.7 ± 2.1 (33.8–38.8) teeth/mm.

Song. (n = 6) Typical Convexa Clade “zwee-zwee” song type but with a significantly slower PTR of 1.8± 0.1 s- 1 (ANCOVA P = 1.08×10 -5) and longer MPTL of 498.2 ± 65.5 ms (ANCOVA P = 4.27×10 -11) than all other Convexa Clade taxa. PTF is 13.9 ± 2.2 kHz.

Karyotype. (n=2) 2n♁ = 26 (2m + 22t + Xt +Yt) T19-16, S19-90, paratopotype.

Recognition. The male ventral sclerite of N. cascadia has a blunt apex with scattered large tubercles and a short lateral process that blends into the shaft by an obtuse angle. This contrasts with N. convexa and N. longiplutea , both distributed to the south, which have the ventral sclerite apex low if not flat and a long lateral process with numerous fine tubercles that are arranged in rows. N. steindachneri to the north has a mushroom-shaped ventral sclerite with few large tubercles and a blunt, recurved lateral process. The female subgenital plate is unique among the Convexa Clade in having straight apical margins. The slow PTR separates the song of N. cascadia from all other Carinata Group species; N. steindachneri to the north has the fastest PTR in this species Group.

Etymology. cascadia , reflecting the southern Cascade Range distribution.

Notes. The distribution of this species lies between that of N. steindachneri to the north and N. convexa to the south. Further studies are needed to determine the limits of the ranges of northern Carinata Group taxa. Museum specimens from intermediate localities are nymphs and are only tentatively identified as this species. The calling songs and genitalia of all three species differ, so sympatry may be expected if these differences confer reproductive isolation. That calling song extremes of PTR occur in two species with adjacent ranges suggests prezygotic reproductive isolation mediated by calling song.

Material examined. In addition to type material (above), QUESTIONABLE PLACEMENT (n = 3): USA, OR , Jackson Co., 2♀ nymphs, Little Applegate River , 42.198722N, 123.045356W, 701 m, 6-VIII-1950, B Malkin, CAS ; 1♀ nymph, Union Creek , 42.906905N, 122.445598W, 7-31-VIII-1950, B Malkin, CAS .

Figures

PLATE 1. Live habitus of Carinata Group. A. N. carinata male, B. N. ambagiosa paratypes in phonotaxis, C. N. ambagiosa male (photo credit Jim Hogue), D. N. radicata paratype male, E. N. steindachneri male, F. N. cascadia paratopotype male showing mottled color form, G. N. cascadia paratopotype male singing (note elevated pronotal shield to give tegmina room to move, and perhaps, also create a parabola effect), H. N. cascadia paratyopotype male showing striped color form.

PLATE 4. Male calling songs of the Carinata and Propsti Groups.. A. N. carinata, B. N. oblongata, C. N. ambagiosa, D. N. diabolica, E. N. longiplutea, F. N. radicata, G. N. convexa, H. N. cascadia, I. N. steindachneri, J. N. propsti. Left column shows 4 s oscillogram windows, right column are 1 s windows.

PLATE 7. Ventral sclerites: Carinata, Propsti, Lucubrata, and Castanea Groups. A–C. N. convexa, D. N. steindachneri, E. N. cascadia, F. N. propsti, G–H. N. lucubrata, I. N. castanea, J–K. N. macneilli.

FIGURE 9. Distribution of Carinata Group species showing records in this work.

PLATE 11. Female subgenital plates of Carinata (A–I), Propsti (J), and Castanea (K–L) Group species.

FIGURE 17. N. cascadia male and female habitus, calling song, male and female terminalia, karyotype.