Aglaothorax gurneyi ( Rentz & Birchim, 1968 )

Cole, Jeffrey A., Weissman, David B., Lightfoot, David C., Ueshima, Norihiro & Warchałowska-Śliwa, Elżbieta, 2025, A revision of the shield-backed katydid genus Aglaothorax (Orthoptera: Tettigoniidae: Tettigoniinae: Nedubini), Zootaxa 5667 (1), pp. 1-104 : 36-39

Aglaothorax gurneyi ( Rentz & Birchim, 1968)

Aglaothorax ovatus — Tinkham, 1944: 289 (Incorrect synonymy).

Neduba (Aglaothorax) gurneyi — Rentz & Birchim, 1968: 65.

Fig. 6 (distribution), Fig. 14 (male and female habitus, calling song, male and female terminalia, karyotype), Plate 4 (male terminalia), Plate 7 (female subgenital plate), Plate 10 (male titillators), Plate 14 (male calling song).

Common name. Gurney’s Shieldback.

History of recognition. Confused with A. ovatus ( Tinkham 1944) before description. Described in Neduba (Aglaothorax) ( Rentz & Birchim 1968) . Returned to Aglaothorax ( Rentz & Colless 1990) where it is currently classified ( Cigliano et al. 2025). See Cigliano et al. (2025) for complete synonymy.

Type material. The holotype male deposited in ANSP is from Lake Arrowhead in the San Bernardino Mountains , San Bernardino County , California. Images of the type are available at OSFO ( Cigliano et al. 2025). PARATYPES EXAMINED: (n=5), USA, CA, San Bernardino Co., Barton Flats , 34.172509, -116.863083, 1937 m, 21-VIII-1936, no collector, CAS, 1♀; Lake Arrowhead, 34.248340, -117.189208, 22-VIII-1958, P. Paige, CAS, 1♂; same data except IX-1958, P Palge, CAS, 1♂; same data except VII-1958, no collector, CAS, 1♂; San Bernardino Mountains , 4 mi. W of Running Springs, 34.207766, -117.179377, 2195 m, 12-X-1952, ER Tinkham, CAS, 1♂; TOPOTYPES EXAMINED: (n=11) USA, CA, San Bernardino Co. , San Bernardino Mountains , 0.8 mi. E of Lake Arrowhead City on Hwy 173, 34.248339, -117.175167, 1520 m, 20-VII-1992, DB Weissman, CAS, 2♂, 2♀; SR173 near Old Mill Road, Cedar Glen, 34.2562, -117.1683, 1900 m, 12-VII-2002, JA Cole, AMNH, 1♂, 1♀; same data except LACM, 2♂, 3♀.

Measurements. (mm, ♂ n=6, ♀ n=8) Hind femur ♂ 18.04–19.80, ♀ 19.84–22.60, pronotum total length ♂ 12.15– 13.40, ♀ 11.35–13.10, prozona length ♂ 4.77–5.48, ♀ 5.25–7.54, metazona dorsal length ♂ 6.82–8.18, ♀ 5.05–7.50, pronotum constriction width ♂ 3.35–3.75, ♀ 2.94–4.77, metazona dorsal width ♂ 8.05–9.20, ♀ 7.21–8.80, head width ♂ 5.40–5.90, ♀ 5.25–6.74, ovipositor length ♀ 16.75–19.45.

Distribution. San Bernardino and San Gabriel Mountains of the Transverse Ranges of Southern California.

Habitat. Coniferous forest understory. Taken from Ceanothus spp. , Whorl-leaf Penstemon ( Keckiella sp. ), peavines ( Lathyrus sp. ), Pinus spp. , and California Black Oak ( Quercus kelloggii Newberry ). Hides in leaf litter at the base of vegetation during the day. Several males (S89-56) collected singing at night from piles of brown twigs on the ground. Males also heard in the canopy.

Seasonal occurrence. Summer (7-VII-2004, JA Cole, LACM) through Fall (12-X-1952, ER Tinkham, CAS), adults presumably active until first freezing weather. Nymphs present into summer (1-VII, no collector, CAS).

Stridulatory file. (n=6) length 4.75–5.30 mm, 93–105 teeth, tooth density 19.3±0.8 (18.2–20.2) teeth/mm.

Song. (n=28) Frequently repeated single pulse trains or echemes that consist of no more than two pulse trains. Pulse trains last 70±20 s and repeat at a rate of 8.20± 0.94 s- 1. Mean peak frequency is 12.41±3.08 kHz, with high frequency recordings showing peak frequencies as high as 18.93 kHz. The silent interval between echemes lasts 0.41–0.94 (mean 0.70±0.11) s.

Karyotype. (n=5) 2n ♂ =24 (22t +XtYt), T89-38 (S89-56).

Recognition. Morphology, song, geography, habitat, karyotype. Body color wood-brown instead of the green, yellow, or tan of other Ovatus Group species, and without a reddish middorsal abdominal stripe. Tegmina brown instead of white as in other Ovatus Group species. Calling song with maximum of 2 pulse trains/echeme. Geography and habitat unique among Ovatus Group species: high elevation coniferous woodland in San Gabriel and San Bernardino Mountains as opposed to desert shrubland, pinyon-juniper, or Joshua tree woodland. Karyotype 2n ♂ =24 shared only with A. segnis among the Ovatus Group species.

Notes. This species is sister to all other members of the Ovatus Group ( Figs. 2–4 ; Cole 2016) suggesting that this is a relict lineage that has been isolated in the sky islands of the San Bernardino and San Gabriel Mountains for some time. Populations are sympatric with A. hulodomus in the San Bernardino Mountains where chaparral meets mixed woodland. This is the only Ovatus Group species that inhabits mesic mixed woodlands. Males call from a variety of heights, most commonly on the forest floor but also in low bushes and high in conifers and oaks. Singing males may be difficult to approach surrounded by dry oak and pine leaf litter, the disturbance of which renders the singer silent for many minutes.

Material examined. (n=51) Los Angeles Co., Mescal Picnic Area , Angeles National Forest , 5 miles northwest of Wrightwood on County Road N4 (Big Pines Highway), 34.3901, -117.7206, 1868 m, 16-VII-2002, JA Cole, 1♂, 1♀ JAC; same data except 7-VII-2004, 2♂ , LACM; same data except 8-IX-2008, 4♂ , LACM; same data except 1♂ JAC; San Bernardino Co. , 0.7 mi. W of Skyforest on Hwy. 18, 34.235284, -117.191491, 1707 m, 17- VIII-1982, DB Weissman, CAS, 2♂ ; Arrowbear Lake , 34.21106, -117.08507, 1867 m, 19-20-VII-2013, JA Cole, JF Eguizabal, 1♂ song record; Barton Flats , 34.172509, -116.863083, 1937 m, 1-VII-1936, no collector, CAS, 1♀ ; Camp O-ongo, near Running Springs , 34.207786, -117.109205, 25-30-VIII-1968, CL Hogue, LACM, 2♂ ; same data except 28-31-VIII-1967, CL Hogue, LACM, 2♂ ; same data except 16-22-VIII-1980, CL & JN Hogue, LACM, 1♂, 1♀ ; same data except 24-25-VIII-1981, CL & JN Hogue, LACM, 1♂ ; same data except 1-IX-1970, CL Hogue, LACM, 1♂ ; same data except 21-27-VIII-1982, JN Hogue, CSUN, 1♂ ; same data except 23-VIII-1979, JN Hogue, CSUN, 1♂ ; same data except 25-VIII-1975, JN Hogue, CSUN, 2♂, 1♀ ; same data except 27-VIII-1975, JN Hogue, CSUN, 1♂ ; same data except 29-VIII-1973, JN Hogue, CSUN, 1♂ ; Crestline , 34.241951, -117.285599, 1439 m, 2-IX-1933, W Brandler, LACM, 1♀ ; Hanna Flat Campground, San Bernardino National Forest , 34.28778, -116.97556, 2152 m, 10-11-VIII-2022, JA Cole, C Wong, LACM, 1♂ ; same data except JAC, 2♂ ; same data except 10-VIII-2023, JA Cole, C Wong, JAC, 1♂ ; Hanna Flat, San Bernardino National Forest , 34.28945, -116.97948, 4-IX-1953, A Menke, LACM, 1♂ ; Running Springs , 34.21518, -117.12670 1913 m, 19-20-VII-2013, JA Cole, JF Ramirez, LACM, 5♂, 2♀ , 1 pair in copula; San Bernardino Mountains , 2.5 mi. NW of Running Springs on Hwy. 18, 34.233429, -117.140217, 1829 m, 17-VIII-1982, DB Weissman, CAS, 5♂ ; San Bernardino Mountains , State Highway 18, 0.7 mi. W & E of Skyforest, 34.235284, -117.191491, 1750 m, 26-VII-1989, DB & DW Weissman, CAS, 5♂ ; San Bernardino , 34.088624, -117.280598, 9-VIII-1978, ER Tinkham, CAS, 1♂ ; Tiron , San Bernardino Mountains , 34.125566, -116.876415, 1829 m, 1-XI-1982, ER Tinkham, CAS, 1♂ ;

ERRONEOUS LABELS: (n=2) USA, CA , San Bernardino Co., Blythe , 33.610302, -114.596346, 81 m, 1- VIII-1933, LJ Muchmore, LACM, 1♂, 1♀ .

Morsei Group

The Morsei Group is one of two Groups of small Aglaothorax species, the other being the Diminutiva Group. Body coloration may be highly variable within species ( Figs. 16–26 , Plate 2 ) but all species lack the green body coloration found in the Ovatus Group ( Plate 1 ). The prosternal spines are usually long and divergent but may be conical ( A. sphenosternum and rarely A. bufonoides and A. kelainops ) or reduced and nipple-like. Chaetotaxy is more variable within species (and sometimes within individuals) than between ( Table 3). The male supra-anal plate is rounded, square, or heart-shaped with the dorsal surface flat to concave. The male subgenital plate has a narrow to wide apex that is transverse to rounded to pyramidal. Most males have a subapical internal tooth on the paraproct, but the tooth is apically situated in A. bufonoides , A. conistylus , A. kelainops , most A. nesiazo , and A. sphenosternum . The titillators are always short, often barely curved, and may have a notch at the base. The female subgenital plate always has short, triangular lateroposterior processes. The ovipositor is saber-like, regularly upcurved with the apical 1/4 bearing knob-like serrations and is always shorter than the hind femur, from about 1/2 to 3/4 its length.

Relationships within the Group were poorly resolved with nDNA ( Fig. 2 ) but were clearer with mtDNA ( Fig. 3 ), producing a modicum of consensus in the concatenated analysis ( Fig. 4 ). Frequent capture of Diminutiva Group mtDNA was found by this Group ( Fig. 3 ).

This species Group contains the extremes of calling song variation in the genus, from pulse trains produced slowly at approximately 5 s-1 to rapidly at 15 s-1. This entire range of variation may be observed across the Transverse Ranges of Southern California, with the fast rate extreme found in the western Santa Monica Mountains and a regular clinal decrease in rate to the east ( Cole 2010; Rentz & Weissman 1981). Echemes may contain a regular or irregular count of pulse trains.

Figures

PLATE 1. Living habitus of Ovatus Group.

FIGURE 2. Bayesian consensus tree of nDNA matrix. Nodes with less than 85% posterior probability are collapsed. Terminals in red show mitochondrial capture in Fig. 3.

FIGURE 3. Bayesian consensus tree of mtDNA matrix. Nodes with less than 85% posterior probability are collapsed.Terminals in red are Diminutiva Group exemplars that experienced mitochondrial capture into the Morsei Group.

FIGURE 4. Bayesian consensus tree of concatenated matrix. Terminals in red show exemplars involved in mitochondrial capture.

PLATE 2. Living habitus of Morsei Group.

PLATE 4. Male terminalia of Ovatus Group, dorsal view.

FIGURE 6. Distribution of Ovatus Group species.

PLATE 7. Female subgenital plates of Ovatus Group, ventral view.

FIGURE 14. A. gurneyi male and female habitus, calling song, male and female terminalia, and karyotype. Idiogram shows karyotype 2n♂=24. Sex chromosomes X and Y are marked.

FIGURE 16. A. morsei male and female habitus, calling song, male and female terminalia, and karyotype. Idiogram top panel shows karyotype 2n♂=24; B. Metaphase I plate showing associated X and Y chromosomes, which ensures proper segregation to opposite poles; C and D showing metaphase II cells with X chromosome in C and Y chromosome in D.

FIGURE 17. A. costalis male and female habitus, calling song, male and female terminalia, and karyotype. Idiogram shows karyotype 2n♂=24.

FIGURE 18. Variation in A. costalis including previously recognized subspecies synonymized in this work.

FIGURE 19. A. longipennis male and female habitus, calling song, male and female terminalia, and karyotype. Idiogram shows karyotype 2n♂=24.

FIGURE 20. A. amathitis male and female habitus, calling song, male and female terminalia, and karyotype. Idiogram showing karyotype 2n♂=24, S92-58, T92-28.

FIGURE 21. A. islandica male and female habitus, calling song, male and female terminalia, and karyotype. Idiograms of karyotype 2n♂=24 showing differences in preparation techniques: A. prepared by NU, B. F1 prepared by EWS.

FIGURE 22. A. hulodomus male and female habitus, calling song, male and female terminalia, and idiogram of karyotype 2n♂=24.

FIGURE 24. A. nesiazo male and female habitus, calling song, male and female terminalia, and karyotype. Idiogram shows karyotype 2n♂=24.

FIGURE 25. A. bufonoides male and female habitus, calling song, male and female terminalia, and karyotype. Idiogram A. karyotype 2n♂=24; B. Same male, metaphase I with small Y and large X sex chromosomes labeled.

FIGURE 26. A. kelainops male and female habitus, calling song, male and female terminalia, and karyotype. Idiogram A. showing karyotype 2n♂=20, showing two largest autosomal pairs composed of metacentric chromosomes; B. Metaphase I in same male showing association of X and Y sex chromosomes; and two largest pairs of metacentric (M) autosomes.