Gryllus navajo Weissman & Gray, 2019

Weissman, David B. & Gray, David A., 2019, Crickets of the genus Gryllus in the United States (Orthoptera: Gryllidae: Gryllinae), Zootaxa 4705 (1), pp. 1-277 : 254-258

Gryllus navajo Weissman & Gray , n. sp.

Painted Desert Field Cricket

Figs 236–238 , 252–256 , 259–262 , Table 1

‘G. #39’ in DBW notebooks.

Distribution. Southeastern Utah and northern Arizona.

Recognition characters and song. A slender, medium sized cricket always with short hind wings, frequently with both reddish tegmina and entire hind femur ( Fig. 260 ), very long antennae in some populations (e.g. S07- 56) reaching past tip of abdomen in situ. Cerci always longer than hind femur and in certain populations, usually longer than ovipositor tip in situ. Song ( Fig. 259 , R07-61) with 4–5 p/c (range 3–6), 75–180 c/m, PR 16–25. One of morphologically similar, never sympatric western US Gryllus spp. including G. makhosica , G. saxatilis , and G. leei . Distinguished from DNA similar but allopatric sister species G. makhosica from South Dakota by the following (and see Discussion, and comparative regressions, under G. makhosica , p. 251): general body color, especially hind femurs, more reddish in G. navajo vs. dark in G. makhosica , pronotum shinier in G. navajo ; G. navajo lives in sandstone badlands vs. clay badlands for G. makhosica . Chirps in G. makhosica average 3–4 p/c vs. 4–5 in G. navajo . Elsewhere, under G. makhosica , we make several physical comparisons, employing regression analysis, between file teeth number, length of file, teeth/mm, tegmina length, hind femur length, and ovipositor length. While there is overlap in all of these metrics for these two species, their nearest populations are separated by some 850 km. Distinguished from sister species G. saxatilis whose cerci almost never longer than ovipositor and rarely (except at Checkerboard Mesa, Zion National Park) in open sandstone habitats and usually associated with rocks. Distinguished from Utah sister species G. leei which inhabits lava flows, has a shorter ovipositor and is separated by the Pahvant Mt. Range and Sevier Plateau of central Utah from G. navajo . Distinguished ( Table 1 , p. 18) from G. longicercus by G. navajo having fewer teeth in file, shorter cerci length, higher pulse rate, and different DNA (Gray et al. 2019).

Holotype. Male ( Fig. 260 ). USA, Utah. Emery Co., 6.5 m W of Hwy 24 and 1.3 m W turnoff for Goblin Valley State Park , 5400’, S92-108, R92-180, BL 17.67, HF 10.3, LC 10.2. Right tegmen removed, 154 teeth, FL 3.4, TL 10.2, TW 4.3. Type deposited in CAS, Entomology Type #19268.

Paratypes. (Total: 43♂ 35♀). Arizona. Coconino Co., 49 m E Flagstaff on Hwy 99 ~6.85 road m NW I40, mile post 59.5, 4838’, 35° 08.548’ -110° 53.535’, 8-viii-1991, (S91-89) 8♂ 11♀; 12-vi-1996 (S96-64) 2♂ 1♀; 14-vi- 2007 (S07-56) 13♂ 13♀. Moenkopi Dune area on Hwy 264 3.1 m SE Tuba City , 4680 ’, 6-viii-1991 (S91-82) 7♂ 1♀; 7-ix-1999 (S99-111) 1♂. Utah. Type locality, 1-viii-1992 (S92-108) 7♂; 11-vi-1996 (S96-58) 3♂ 9♀. Wayne Co., Hwy 24 3 m NE Hanksville , 11-vi-1996 (S96-60) 2♂.

Other collections, not counted as paratypes. Utah. Emery Co., Goblin Valley State Park , campground, 5000’, 18-v-2016, 10♂ 19♀ . Black Dragon Canyon , 4350’, 24-v-2017, 32♂ 8♀ . San Juan Co., Oljato-Monument Valley, Douglas Mesa Rd. ( County Road 419) 6 m N Utah—Arizona border, 5575’, 26-v-2017, 10♂ 3♀ .

Derivation of name. Named for the Native Americans (Diné) of the Navajo Nation who inhabit this area.

Geographic range. ( Fig. 261 ) Southeastern Utah and northern Arizona, associated with Painted Desert red sandstone outcrops and escarpments and occasionally rocky outcrop areas, as at type locality.

Habitat. Singing from cracks in sandstone cliffs at Moenkopi Dunes (S91-82), near Hanksville (S96-60), and at 79 km E Flagstaff (S07-56) and occasionally in valley floors. Many more males walking around at Goblin Val- ley (S96-58) and 79 km E Flagstaff (S07-56) than singing: at S07-56, for every male heard singing, we collected 5 males (and many females) at a long oatmeal trail laid in the open, vegetated, sandy valley floor away from the sandstone escarpments. At Goblin Valley, it appears that the crickets live within cracks in the mudstone/sandstone escarpments during the day, and then descend to forage on the valley floor at night; adult males call both from cracks in the escarpments and from the valley floor (often from under the meager plant cover), whereas females and nymphs more likely encountered on the valley floor (DAG observations 14-vi-1999, 9-viii-2005, 18-v-2016, 25-v- 2017, 20-22-v-2018).

Life cycle and seasonal occurrence. No egg diapause Moenkopi Dunes (S91-82); Goblin Valley (May collections, 2016-2018); capable of multiple generations per year under lab conditions, but situation in the field less clear. Adults known from mid-May through early September with nymphs also collected during June through August visits. For instance, collections in May at Goblin Valley were mostly of adults: (18-v-2016) 9 adult males, 19 adult females, 1 nymph male; (26-v-2017) 54 adult males, 36 adult females, 1 nymph female and 1 nymph male, whereas collections in August (1-viii-1992 and 9-viii-2005), only many early to mid-instars seen. It is not clear to us if these August nymphs represent what will become a second generation, or if those nymphs will be the ones that overwinter until spring. Given that the average high/low temperature in September and October is 30.6/10.0 oC and 22.2/2.8 oC, respectively (https://weather.com/weather/monthly/l/Goblin+Valley+State+Park+UT+USUT0091:1: US), we suspect that these August nymphs overwinter rather than become an adult second generation.

Variation. Color: Individuals vary from solid red ( Fig. 262 , Moenkopi Dunes, S91-82) to almost solid black except for the hind femurs, which are usually reddish. Most females with tegminal bars. Head: varies from red to black, many times with a black face and a reddish top of head. Cerci length: 17 of 24 females from the 3 collection dates at 79 km E Flagstaff have their cerci longer than the ovipositor tip in situ. In all other collections, the female cerci in situ are slightly shorter than the ovipositor tip.

DNA. Multilocus 2016-040 (type locality, Goblin Valley State Park, campground) and G1067 (79 km E Flagstaff, S07-56) sister species (Gray et al. 2019) with widespread G. saxatilis , Utah lava G. leei , and South Dakota Badlands G. makhosica .

Discussion. The question arises if G. navajo could just be an edaphic color form of some Gryllus , especially G. saxatilis or G. makhosica , that is darker when living away from red sandstone? We think not, especially when one considers the unique behavior displayed by this species at the type locality and E Flagstaff (S07-56)—their high density and the tendency of both sexes to walk around away from cover is unusual in Gryllus and certainly unknown for any similar western taxon discussed under “Recognition characters” (but note G. lightfooti does this in some dense populations, e.g. Maricopa Co. , AZ, 33.97995, -111.87249, 8-viii-2016). Lab cultures continue to produce variably reddish individuals and do not simply result in dark G. saxatilis -like coloration. Genetic structure of cricket populations in and around the Colorado Plateau is being examined by E. Collosi et al. using RAD-seq SNP data, and should help clarify the situation with respect to G. navajo and G. saxatilis .

G. navajo were poor singers in the field E Flagstaff (S07-56), and we have found that in some other Gryllus species, when at high densities, males do not need to sing much to attract females since both sexes are mobile and would easily find each other with random walkabouts (and maybe assisted by their long antennae?). Once back in the laboratory, these males sang well. In contrast, male G. navajo singing well in the field at Moenkopi Dunes (S91- 82) and Goblin Valley (S96-58), sang poorly once in the laboratory: of 7 males collected 6-viii-1991 at Moenkopi, the first male was recorded 31-viii; for the 3 Goblin Valley males collected 11-vi-1996, the first male was recorded 5-vii. On the other hand, adult males collected in May, 2017, were relatively easy to record (N= 112 males from several localities). Such variable, taciturn behavior may also reflect past, high tachinid parasitism, although despite our multiple collecting trips, we have never collected a single tachinid-parasitized G. navajo !

Lots of red mites on both sexes E Flagstaff (S91-89 and S07-56) on two visits.

Figures

FIGURE 236. Five second waveforms of calling songs of (A) G. saxatilis, (B) G. leei, (C) G. makhosica, and (D) G. navajo. G. saxatilis: (R15-372) from type locality (S15-114), at 25.5°C. G. leei: (R17-7) from type locality (S17-6), at 24.5°C. G. makhosica: (R09-95) from type locality (S09-89), at 24.5°C. G. navajo: (R07-61) from Coconino Co., AZ (S07-56), at 25°C.

FIGURE 237. One second spectrograms of (A) G. saxatilis, (B) G. leei, (C) G. makhosica, and (D) G. navajo, same males as in Fig. 236.

FIGURE 238. ITS2 gene tree, color coded to highlight species and potential cryptic species warranting further study. Collection stop numbers for G. saxatilis legs: S04-51 (G216); S04-62 (G223, G224); S04-74 (G262, G263, G264); S04-121 (G361, G362); S05-109 (G514); S06-5 (G535); S06-21 (G533, G534, G537); S06-105 (G639, G641); S07-64 (G1131); S09-22 (G1306); S09-28 (G1300); S09-29 (G1304, G1307); S09-32 (G1301); S09-43 (G1328); S09-131 (G1449); S09-141 (G1448); S12-34 (G2246); S13-10 (G2457B, G2460, G2717, G2718); S13-10A (G2719, G2720); S13-79 (G2705, G2706, G2707, G2711); S14- 30 (G2748, G2749); S14-61 (G2809, G2813); S14-77 (G2803); S15-87 (G3176, G3180); S15-89 (G3184, G3190); S15-90 (2016-045); S15-93 (G3308); S15-96 (G3372); S16-17 (G3409, G3410, G3411, G3415); S16-18 (G3429, G3431); S16-21 (G3413, G3422, G3427, G3449); S16-23 (G3434, G3446); S16-33 (G3424); S17-7 (G3471, G3473, G3474, G3477, G3483, G3484); La Verkin overlook, Washington Co., UT (2016-027). Collection stop numbers for G. leei legs: S01-28 (G146, G147); S17-6 (G3470, G3472, G3475, G3476, G3487). Collection stop numbers for G. makhosica legs: S09-89 (G1340, G1363). Collection stop numbers for G. navajo legs: S07-56 (G1124, G1125, G1198, G1215); Goblin Valley, Emery Co., UT (2016-050).

FIGURE 252. Regression file length vs. number file teeth in G. makhosica vs. G. navajo.

FIGURE 253. Regression number file teeth vs. tegmen length in G. makhosica vs. G. navajo.

FIGURE 254. Regression number file teeth vs. hind femur length in G. makhosica vs. G. navajo.

FIGURE 255. Regression number file teeth vs. teeth/mm in G. makhosica vs. G. navajo.

FIGURE 256. Regression hind femur length vs. ovipositor length in G. makhosica vs. G. navajo.

FIGURE 259. Calling song (R07-61) of G. navajo from Coconino Co., AZ (S07-56), recorded at 25°C.

FIGURE 260. Holotype male of G. navajo.

FIGURE 261. Known distribution of G. navajo.

FIGURE 262. Color variation in G. navajo. Viewing left to right: holotype male from Goblin Valley, UT (S92-108); male from Coconino Co., AZ (S07-56); female (with spermatophore) from Coconino Co., AZ (S91-89); and red male from Moenkopi Dunes, AZ (S91-82).