Neduba sierranus (Rehn & Hebard, 1910)

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 : 57-59

Neduba sierranus (Rehn & Hebard, 1910)

Fig. 19 (distribution), Fig. 24 (male and female habitus, calling song, male and female terminalia, karyotype), Plate 2 F–G (live habitus), Plate 5D (male calling song), Plate 8A (male ventral sclerite), Plate 10E (male titillators), Plate 12B (female subgenital plate).

Common name. Yosemite Shieldback.

History of recognition. Described in Aglaothorax from Yosemite Valley (Rehn & Hebard 1910) and transferred to Neduba ( Rehn & Hebard 1912) . The Tulare and Kern County records in Rentz and Birchim (1968) belong to Sequoia Group species that are described in this work ( N. sequoia and N. prorocantans ).

Type material. The holotype male is in ANSP . Images of the holotype are available at OSFO ( Cigliano et al. 2020). TOPOTYPES : All USA, CA , Mariposa Co., 2♁, Carl Inn , Yosemite, 12-VIII-1938, ER Tinkham, CAS ; 4♁, Yosemite National Park , Wawona, 37.53694N, 119.65528W, 1223 m, 27-VIII-1982, DB & BI Weissman, CAS ; 4♁, 4♀, Yosemite National Park , Wawona Area, Redwood Estates, 37.53694N, 119.65528W, 1250 m, 23-25-VI-1989, DB Weissman, CAS .

Measurements. (mm, ♁n = 14, ♀ n = 5) Hind femur ♁18.11–22.25, ♀ 21.92–23.60, pronotum total length ♁7.87–9.90, ♀ 8.54–9.00, prozona length ♁3.80–4.99, ♀ 4.35–4.91, metazona dorsal length ♁4.01–5.45, ♀ 3.83– 4.50, pronotum constriction width ♁2.60–3.23, ♀ 2.85–3.20, metazona dorsal width ♁5.47–6.67, ♀ 5.64–6.05, head width ♁4.50–5.40, ♀ 5.20–5.65, ovipositor length ♀ 13.75–14.84.

Distribution. Western slope of the Central Sierra Nevada of California, distributed between the Merced and Mokelumne River watersheds in the vicinity of Yosemite National Park.

Habitat. Mixed conifer forests. Males call from dense understory vegetation and from pine needle litter, most commonly 15 cm or less from the ground but occasionally as high as 3 m above the ground in conifers. This species is associated with mountain misery ( Chamaebatia foliosa Benth. ), incense cedar ( Calocedrus decurrens (Torr.) Florin ), western bracken fern ( Pteridium aquilinum (L.) Kuhn), and white fir ( Abies concolor (Gord. & Glend.) Lindl. ex Hildebr. ).

Seasonal occurrence. Adults have been taken from early July (9-VII-1968, TR Haig, CSCA) into mid-September (12-IX-2015, JA Cole, LACM). Last instar nymphs from late June into early July.

Stridulatory file. (n = 7) length 2.9–3.6 mm, 196–234 teeth, tooth density 66.1 ± 5.9 (58.8–75.5) teeth/mm.

Song. (n = 14) The calling song of this species was published in Morris et al. (1975). The song of N. sierranus , like all other species in the Sierranus Group, has a complex pattern of several OPT between MPT, and gives the song a “fluttering” quality as perceived by a human listener. The PTF is 16.2 ± 1.2 kHz, and at this high carrier frequency the songs of these insects are difficult for many humans to hear, and a listener must be in close proximity to the singing male to detect him. The PTR of 1.7 ± 0.3 s- 1 is the fastest rate among the Sierranus Group (ANCOVA, P = 3.96×10 -9).

Karyotype. (n = 9) 2n♁ = 21 (18t + XtXtYm), shared only with N. duplocantans . T89-20, S89-47, topotype.

Recognition. Males may be identified by the combination of a high stridulatory file tooth density (62–70 teeth/ mm) and a pronotum that is not strongly constricted. N. sierranus has two parapatric neighbors that also have high tooth densities: N. inversa to the south and N. radocantans to the north, but those species have stronger pronotum constrictions. The PTR is faster than all other species with multiple OPT ( N. arborea , N. radocantans , and N. inversa ). Karyotype also separates this species from N. radocantans and N. inversa . The subtriangular subgenital plate that is longer than wide is unique among the Sierranus and Sequoia groups.

Notes. Based on comparison of rDNA and mtDNA topologies ( Fig. 4 ), this species has hybridized with its parapatric neighbors to the south and north: N. inversa and N. radocantans , respectively. The three species are morphologically cryptic. Species status for Sierranus Group lineages is based on song and karyotype. Song differences between these three species may reinforce prezygotic isolation if hybrids between species that differ in chromosome arrangement suffer reduced fitness.

Material examined. DETERMINED (n = 23): Calaveras Co., 1♁, 1♀, Golden Pines RV Resort and Campground, 38.29808N, 120.28773W, 1570 m, 14-15-VIII-2015, JA Cole, LACM ; Madera Co., 4♁, 2♀, Narrow Gauge Inn , Fish Camp, 37.45506N, 119.64345W, 1435 m, 11-12-IX-2015, JA Cole, LACM ; 1♀, Narrow Gauge Inn , Fish Camp, 37.45506N, 119.64345W, 1435 m, 11-12-IX-2015, JA Cole, JAC ; Mariposa Co., in addition to type material (above), 1♁, 1 mi. W El Portal , 37.67465N, 119.80238W, 29-VII-1965, RP Allen, CSCA ; 1♀, Hites Cove , 37.64083N, 119.84806W, 9-VII-1968, TR Haig, CSCA ; 1♁, Jerseydale Campground , Sierra National Forest, 13.5 miles northeast of Mariposa, 37.5451N, 119.8386W, 1131 m, 10-11-VIII-2002, JA Cole, LACM ; 1♁, 1♀, same data except JAC ; 3♁, same data except 28-29-VII-2012, JA Cole, LACM ; Tuolumne Co., 3♁, Mill Creek Campground, Stanislaus National Forest , FR5N21 off Mono Way ( SR108 ), 38.30168N, 119.93763W, 1918 m, 23-24- VIII-2019, JA Cole, J Bailey, SA Downing , LACM ; 2♁, same data except JAC; QUESTIONABLE PLACEMENT (n = 5) : Amador Co., 1♀, Ponderosa Rd. , 1.5 mi. N of Mokelumne River, 38.34889N, 120.77306W, 21-VIII-1984, RW, BMED ; Calaveras Co., 1♀, West Point , 38.399079N, 120.527426W, 18-VIII-1929, CAS ; Madera Co., 1♀, Bass Lake , 37.324666N, 119.566254W, 20-VII-1934, FE Blaisdell, CAS ; 1♀, Oakhurst , 37.328N, 119.649315W, 914 m, 29-VI-1946, HP Chandler, CAS ; Tuolumne Co., 1♀, Jamestown , 37.953258N, 120.422695W, 429 m, 1978, Schultz, CSCA .

Figures

PLATE 2. Live habitus of the Propsti, Castanea, Lucubrata, and Sierranus Groups. A. N. propsti male, B. N. castanea topotype male, C. N. castanea female, D. N. macneilli male (photo credit James Bailey), E. N. lucubrata paratype male, F. N. sierranus female, G. N. sierranus male singing (note visible tegmina under pronotal shield).

FIGURE 4. Comparison of A. rDNA, and B. mtDNA trees. Nodes with <85% posterior probability are collapsed. Species Groups are color coded.

PLATE 5. Male calling songs of the Castanea, Lucubrata, Sierranus, and Sequoia Groups. A. N. castanea, B. N. macneilli, C. N. lucubrata, D. N. sierranus, E. N. radocantans, F. N. arborea, G. N. inversa, H. N. prorocantans, I. N. sequoia, J. N. duplocantans. Left column shows 4 s oscillogram windows, right column are 1 s windows.

PLATE 8. Ventral sclerites: Sierranus and Sequoia Groups. A. N. sierranus, B. N. radocantans, C. N. arborea, D. N. inversa, E. N. prorocantans, F–H. N. sequoia.

PLATE 10. Titillator arms of Propsti (A), Castanea (B–C), Lucubrata (D), Sierranus (E–F), and Sequoia (G–I) Group species.

PLATE 12. Female subgenital plates of Lucubrata (A), Sierranus (B–D), and Sequoia (E–H) Group species.

FIGURE 19. Distribution of Propsti, Castanea, Lucubrata, Sierranus, and Sequoia Group species mapping records reported in this work.

FIGURE 24. N. sierranus male and female habitus, calling song, male and female terminalia, karyotype.