Gryllus leei 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 : 246-250

publication ID	https://doi.org/ 10.11646/zootaxa.4705.1.1
publication LSID	lsid:zoobank.org:pub:F534C43A-AB09-4CB3-9B08-FD5BDFD90298
persistent identifier	https://treatment.plazi.org/id/182387A8-0994-FF6B-51F6-FB030087FF61
treatment provided by	Plazi
scientific name	Gryllus leei Weissman & Gray
status	sp. nov.

Treatment

Gryllus leei Weissman & Gray , n. sp.

Utah Lava Field Cricket

Figs 231 View FIGURE 231 , 236–238 View FIGURE 236 View FIGURE 237 View FIGURE 238 , 240 View FIGURE 240 , 247–250 View FIGURE 247 View FIGURE 248 View FIGURE 249 View FIGURE 250 , Table 1 View TABLE 1

Distribution. Known only from lava flows in the Black Rock Desert of west-central Utah.

Recognition characters and song. A small-medium, always short hind winged, generally black, shiny pronotum, small headed, short ovipositor, cerci always longer than ovipositor in situ Gryllus ( Fig. 249 View FIGURE 249 ). Song a chirp ( Fig. 247 View FIGURE 247 , R17-7) of usually 4 (range 3–5) p/c, PR 17.5–22, CR 105–200 (range 98–225). Most importantly, because multilocus G. leei maps close to multilocus G. saxatilis , we can separate the two even though they are found only ~14 air km from each other, as follows: G. leei is smaller (S01-28, S17-6), with the longest body-length individual being shorter than the smallest individual of G. saxatilis (S01-30, S17-7), with good sample sizes from both populations. If the same species, it then logically follows that G. leei might have (see Table 1 View TABLE 1 , p. 18) fewer file teeth, shorter files and shorter tegmina, and (non-overlapping) shorter ovipositors than nearby G. saxatilis . What doesn’t necessarily follow is that G. leei has proportionally longer cerci, almost non-overlapping teeth/mm, and a different dominant frequency calling song. For the latter, 24 males from the type locality (S17-6) had a dominant frequency from 4017–5211 Hz while 15 males G. saxatilis from nearby (S17-7) had a dominant frequency of 3593–4097 Hz. Most male G. leei (20 of 22–91%) with 3–4 (rarely 5) harp veins while 12 of 13 (92%) nearby G. saxatilis have 4–5 (rarely 3) harp veins. Additionally, the cerci are longer, in situ, than the tip of the ovipositor in all 14 type locality females of G. leei while shorter than the tip in all 10 females of nearby (S17-7) G. saxatilis . This trend is confirmed when we regress ovipositor length on hind femur length (as an indicator of body size) ( Fig. 248 View FIGURE 248 ; hind femur: F 1,20 = 87.72, p <0.0001, species: F 1, 20 = 81.16, p <0.0001, species*hind femur F 1,20 = 0.10, p = 0.748).

If individuals from both populations were the same species, even if with different body lengths, we would expect them to fall on the same regression line with a similar Y axis intercept. Apparently living in lava flows favors a shorter ovipositor than living off of lava, even if both species probably oviposit into the soil. There is also evidence that these smaller and lower elevation G. leei (S17-6) may molt to adult before G. saxatilis in central Utah (S17-7): 29 of 37 (78%) G. leei individuals collected on 20-v-2017, at 1418m, were adult while 12 of 24 (50%) G. saxatilis individuals collected on the same date, at 1598m, were adult. On the other hand, perhaps the larger G. saxatilis simply take longer to become adult because they are larger, as indicated by their longer hind femur lengths.

Distinguished from a number of allopatric lava and rock-associated Gryllus as follows: From New Mexico lava G. vulcanus , no overlap ( Table 1 View TABLE 1 , p. 18) in number of teeth and PR and different DNA. From rock G. longicercus , almost no overlap in number of teeth, PR, cerci length, and DNA. From allopatric eastern Utah G. navajo by habitat (sandstone badlands vs. lava), general body and tegmina color (reddish vs. black), antennae length longer than body in G. navajo , and the Pahvant Mt. Range and Sevier Plateau between the two species. From allopatric South Dakota badlands G. makhosica , no overlap in file length, teeth/mm, tegmina length and width, hind femur length, ovipositor length and PR. From allopatric Texas rock G. transpecos , distinguished by G. leei ’s smaller size, slower PR, shorter ovipositor, habitat, and DNA with the nearest populations separated by some 1110 km. G. veletis sympatric with G. leei but can be easily separated by the former’s shorter cerci which never approach the ovipositor tip in situ, being located away from lava, and more robust, larger body size.

Holotype. Male ( Fig. 249 View FIGURE 249 ): Utah, Millard Co., 2.05 m NW Flowell and 8.5 m NW Fillmore , 20-v-2017, 4653’, 38° 59’ 52.30” -112° 27’ 32.94”. D.B. Weissman, D. W. Weissman. S17-6, R17-6. DNA sample G3480. BL 17.44, HF 9.46, RC 11.07. Right tegmen removed: 3 harp veins, 144 teeth, file length 2.8, TL 9.5, TW 3.9. Type deposited in CAS, Entomology Type #19277.

Paratypes. (Total: 30♂ 14♀). Same locality data as holotype: 18-v-2001 (S01-28) 7♂ 4♀; 20-v-2017 (S17-6) 23♂ 10♀ .

Etymology. Named for Vincent F. Lee of the CAS, for helping to collect the initial series and for never complaining, during many field trips, when asked to help collect “one more cricket” at 04:30.

Geographical range. See Fig. 250 View FIGURE 250 . Known only from the type locality.

Habitat. Many males sing from deep crevices and cracks, within vegetated lava flows, where they are almost impossible to catch, even using water for flushing. Fortunately, a good number of juvenile and adult males and females were under lava rocks that were resting on soil, around edges of main lava flow. Walking into the lava field at night, we heard males singing more than 50 meters from lava’s edge on 20-v-2017, although not as common as on the lava’s perimeter. Utah’s Black Rock Desert volcanic field is a heterogeneous mix of flows from 6.1 MYA with continuous activity from 2.7 MYA to the present, including the most recent eruptions 720 years ago (USGS: https://volcanoes.usgs.gov/volcanoes/black_rock_desert/).

Life cycle and seasonal occurrence. No egg diapause (S17-6). Probably one generation/year, overwinter as late instars with first adults probably appearing in early-May. No nymphs seen when series collected 18-v-2001, despite a cool, wet spring in Utah. On 20-v-2017, we collected 22 adult males, 7 adult females, and 8 late instars. Also listened here 19-iv-1999 and 11-ix-1998 (apparently too late) without hearing any singing males.

One generation/year also supported by these observations: Adults collected May 20 th were maintained together under ambient light conditions, at fluctuating temperatures between 18-30°C, and allowed to mate. Females were then isolated in cartons with moist sand, for oviposition, starting on May 30. Very good egg hatch commenced on June 26, indicating the absence of an obligate egg diapause. Many, but not all, nymphs in both cultures grew rapidly with the first adults appearing around September 12 th in both containers, confirming the possibility of 2 generations/ year. Still, a fair number of nymphs were only mid-instar in mid-September. So, while this species could have 2 generations/year, on site observations support a univoltine sspecies. And we wonder if Gryllus in areas with monsoon rains have more variability in instar development than those in California with its more predictable drought periods of a Mediterranean climate?

Variation. Color: Variable amount of red on inner rear leg femur. Two of 10 2017 females with tegminal bars.

DNA. Multilocus G147 (S01-28) and G3475 (S17-6) map (Gray et al. 2019) with sister taxa G. saxatilis (G3484, S17-7, from 14 km E of type locality and the closest population of G. saxatilis to the type locality of G. leei ), G1067 G. navajo , and G1340 G. makhosica . ITS2 gives (at best) modest separation of G. leei from G. saxatilis ( Fig. 238 View FIGURE 238 , p. 236 View FIGURE 236 ).

Discussion. Singing on arrival at type locality at 18:00 on 18-v-2001 and 19:00 on 20-v-2017, well before sunset. Lava flows in this area from 600 to 15,500 years old ( White 1996). The main flow measures, on Google Earth, some 8.5 km wide north to south and 9 km wide east to west. The lava bed is like an island separated from the surrounding flat plains without rocky, suitable habitat for G. saxatilis .

There is one other lava flow obligate Gryllus in the western US: G. vulcanus from New Mexico. But not all lava flows are inhabited by Gryllus : at extensive lava flows in Lake Co., SE Oregon (43° 35.5’ -121° 1.43’), no Gryllus heard 1-vi-1997 despite area looking favorable.

We wonder if the short ovipositor is related to living in lava fields with shallow substrate for oviposition? It would be of interest to know if G. leei females oviposit directly into the substrate or can they use pockets of soil and debris within the lava field?