Gryllus texensis Cade and Otte

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 : 90-96

Gryllus texensis Cade and Otte

Southeast Fast Trilling Field Cricket

Figs 71–73 , 78 , 79 , 82–90 , Table 1

2000 Gryllus texensis Cade & Otte. Transactions of the American Entomological Society 126: p. 117. Holotype male, Austin, Texas. Holotype male noted as deposited in ANSP, but never done. Neotype male (in alcohol), since no paratypes listed in 2000, designated in 2016 by W. Cade ( Fig. 83 ): Texas, San Antonio , 26-ix-2015, W. Cade. Deposited in ANSP (photos courtesy of J. Weintraub, ANSP) .

‘G. bivoltinus’ or G. integer of pre-2000 DBW notebooks. ‘G. bivoltinus’ was an early manuscript name used by W. Cade for this taxon.

G. integer or ‘ G. integer’ in various published studies prior to 2000.

Distribution. One of three trilling US Gryllus found between western Texas and the Atlantic coast.

Recognition characters and song. Medium to large sized, short or long hind winged trilling crickets with an average PR between 70–80 at 25° ( Fig. 84 ) (but see discussion below for exceptions). Distinguished from morphologically similar and trilling, sometimes sympatric, sister species G. rubens which has an average PR of 55 at 25° and fewer teeth in the file ( Fig. 85 ) and a longer ovipositor ( Fig. 86 ; Gray et al. 2001).

There is no one morphological or song character that always separates G. texensis from G. rubens . Interestingly, along coastal Texas, in 2013, we found no overlap in dominant frequency, in many males, which was <5000 Hz in G. rubens but>5000 Hz in G. texensis . Yet around Tulsa , Oklahoma (S13-68), there is overlap; see under G. rubens (p. 88) for further discussion.

Distinguished from sympatric (western Texas only at Alpine [S07-41]), sister species G. regularis which has non-overlapping PR of 29–50 at 25°. In its most western distribution, G. texensis can be sympatric with G. armatus and while their songs are difficult to separate in the field, unless males are singing near each other when a difference in “evenness” and pitch may be appreciated, the two can be separated by song analysis (2 or 3 p/c in G. armatus vs. a trill in G. texensis ), and by number of file teeth vs. hind femur length ( Fig. 87 ).

Derivation of name. Originally named after the type locality of Texas because much of the early biological research on this taxon was performed in that state.

Geographical range. ( Fig. 88 .) Eastern limits in Gray et al. (2008). Also into adjacent Mexico.

Habitat. Characteristic of pastures, lawns, and other open, grassy areas from sea level to 1300m.

Life cycle and seasonal occurrence. No egg diapause. Two generations/year, second generation more numerous than first and can be locally very common: responsible for cricket outbreaks in Waco, Texas, in early October, 2012 (S12-119, G2432, live specimens courtesy of S. Halvorson, Drug Emporium, Waco)): http://www.npr. org/ 2012/10/01 /162110687/plague-of-crickets-bring-nuisance-stink-to-waco; Norman, Oklahoma, in early September, 2013: https://www.huffingtonpost.com/ 2013/09/04 /oklahoma-cricket-invasion_n_3866683.html; and central Texas in 2015: http://www.cnn.com/ 2015/09/20 /us/cricket-swarm-season-invades-central-texas/index.html.

Variation. Color: Besides black of neotype, individuals can be lighter in color ( Fig. 89 ). Hind wing length: Of 335 adults, 74 (22%) have short hind wings. Females frequently have tegmina bars. Song: A male from Arkansas, Yell Co. (S93-47), was recorded on 19-vi-1993, in the field, (R93-14) at 24.5°C singing with a PR of 49 and pulses grouped into 2’s and 3’s. This same male was re-recorded in the laboratory, while trilling, on 28-vi at 25°C (R93-43) with a PR of 65 and without any grouping of pulses. This male has 121 teeth in his file, 41.7 teeth/mm, and a hind femur length of 11.4 mm, all parameters placing it within G. texensis (see Fig. 87 and Fig. 90 ). We wonder if this male had recently molted to adult and had an “immature” song when first field recorded, even though he did not appear teneral when captured.

A male from Texas, Travis Co. (S85-63), singing at 24°C (R85-46), had a small peak before each large peak, and a PR of 80. Walker (1998) documents that first and second-generation males of G. texensis have different mean modal pulse rates because of both developmental conditions and parental effects. Duration of trills usually shorter in G. texensis than G. rubens but some individuals of G. texensis had long series in Brackettville (S10-63) and Tulsa (S13-68).

Specimens examined. (Total: 224♂ 109♀) [No paratypes designated, or localities cited in original description]. Arkansas: Yell Co., Ola, 19-vi-1993, 500’ (S93-47). Kansas: Barber Co., Medicine Lodge, 23-vi-1987 (S87-68). Clark Co., Ashland, 27-viii-1989, 1950’ (S89-70); 12.2 m E Ashland, 27-viii-1989 (S89-69). Cloud Co., Concordia, 7-viii-2002, 1100’ (S02-50). Ford Co., Dodge City, 27-viii-1989, 2400’ (S89-71). Salina Co., Salina , 7-viii-2002, 1100’ (S02-49). Missouri: Jackson Co., Kansas City, 8-viii-2002, 860’ (S02-54). Nebraska: Fillmore Co., Geneva, 7-viii-2002, 1420’ (S02-51). Lancaster Co., Lincoln, 7-viii-2002, 940’ (S02-52). Red Willow Co., McCook, 28-viii-1989, 2500’ (S89-74). New Mexico: Lea Co., Eunice , 6-ix-2010, 3420’ (S10-62). Oklahoma: Atoka Co., 2.5 m NE Stringtown, 16-vi-1988, 600’ (S88-47). Carter Co., Lake Murray State Park, 24-vi-1993, 900’ (S93-58). Comanche Co., Medicine Park, 6-viii-2002, 1200’ (S02-47). Wichita Mts. Wildlife Refuge, 6-viii-2002, 1300’ (S02- 46). Oklahoma Co., Oklahoma City, 6-viii-2002, 1000’ (S02-48). Texas Co., Guymon, 1-vii-2009, 3380’ (S09-77). Tulsa Co., Keystone State Park, 15-vi-1988, 600’ (S88-42); 23-vi-1993 (S93-56). Lake Keystone Dam area, 22-v- 2001, 650’ (S01-47). Tulsa , 23-vi-1993, 500’ (S93-57); 9-vi-2007 (S07-22); 15-vii-2013 (S13-68). Texas: Bastrop Co., Bastrop State Park, 31-v-1991, 700’ (S91-23). Bosque Co., Clifton, 10-vi-1988, 400’ (S88-29). Brewster Co., Alpine, 4270’, 5-vi-1991 (S91-44), 12-vi-2007 (S07-41). Big Bend National Park, Rio Grande Village, 9-vi-1985, 2100’ (S85-56); 5-vi-1991 (S91-43); 28-v-2016 (S16-12). Calhoun Co., Magnolia Bay, Indian Point Historic Park, 4-viii-2002 (S02-36); Port Lavaca, 12-vii-2013, 18’ (S13-57); 26 m S Victoria, 4-viii-2002, 20’ (S02-37). Cameron Co., Brownsville, 3-vi-1991, 0’ (S91-38); Harlingen, 3-vi-1991 (S91-39); Rio Hondo, 10-vii-2013, 8m (S13-44); FR510 at intersection with FR 2480, 10-vii-2013, 0’ (S13-43); FR510 E near intersection FR100W, 10-vii-2013, 0’ (S13-42). Cass Co., 3 m S Queen City, 18-vi-1993, 400’ (S93-43). Culberson Co., Van Horn, 6-vi-1991, 4100’ (S91-48). Dallas Co., DWF Airport, 23-v-2001 (S01-49). Dallas, 23-v-2001 (S01-50). Irving, 10-vi-1988, 400’ (S88-25). Dimmit Co., Carrizo Springs, 11-vi-2007, 660’ (S07-28). Duval Co., Freer, 25-v-2001, 980’ (S01-52). 4.5 m E Freer, 30-vi-1986 (S86-58). Fayette Co., Schulenburg, 380’, 4-viii-2002 (S02-38), 13-vii-2013 (S13-65); 2.3 m S Schulenburg, 9-ix-2010, 440’ (S10-65). Gillespie Co., Fredericksburg, 1-vii-1986 (S86-65). Harris Co., Cypress, 148’, 13-vii-2013 (S13-64). Hidalgo Co., Bentsen-Rio Grande Valley State Park, 3-viii-2002, 120’ (S02-34); 10-vi- 2007 (S07-27). Howard Co., Big Springs VA Hospital, 30-vi-2009, (S09-72). Jefferson Co., Port Arthur, 1-vi-1991, 0’ (S91-31). Jim Wells Co., Alice, 11-vii-2013, 171’ (S13-48, 49, 50). Kinney Co., Brackettville, 1100’, 10-vi-1985 (S85-61); 27-vi-1986 (S86-47); 4-vi-1991 (S91-40); 12-vi-2007 (S07-35); 7-ix-2010 (S10-63). Matagorda Co., Hog Island, 13-vii-2013, 5’ (S13-59). McLennan Co., Waco, 400’, 10-vi-1988 (S88-26), 3-x-2012 (S12-119), S. Halvorson. Intersection of Hwy 6 and Hwy 35, 10-vi-1988 (S88-27). Nueces Co., Corpus Christi, 29-vi-1986 (S86- 56); 2-vi-1991 (S91-35); 12-vii-2013 (S13-53). Potter Co., Amarillo, 12-vi-1988, 3600’ (S88-38). Tarrant Co., Fort Worth Nature Center & Refuge, 5-viii-2002, 600’ (S02-39). Grapevine Lake Dam, 23-v-2001 (S01-48). Randall Co., Palo Duro Canyon State Park, 12-vi-1988, 3600’ (S88-37). Refugio Co., Tivoli, 12-vii-2013, 12’ (S13-56). Taylor Co., Abilene, 11-vi-1988 (S88-35). Tom Green Co., San Angelo, 11-vi-1988, 1900’ (S88-30). Travis Co., Austin, 11-vi-1985 (S85-63). Uvalde Co., Uvalde, 10-vi-1985 (S85-62). 2.3 m W Uvalde 11-vi-2007, 940’ (S07-29). 6.9 m W Uvalde, 11-vi-2007, 940’ (S07-30). Val Verde Co., Del Rio, 11-vi-2007, 1000’ (S07-33); 7-ix-2010 (S10-64). Del Rio on Amistad Lake some 5 m N Del Rio, 10-vi-1985, 1200’ (S85-60). 5 m E Del Rio on Hwy 90, 27-vi-1986 (S86-49). Ward Co., Monahans, 2-vii-1986 (S86-69). Washington Co., Brenham, 31-v-1991, 300’ (S91-26); 6-ix- 1992 (S92-123); 24-v-2001 (S01-51). Webb Co., 20-48 m W Freer on Hwy 44, 30-vi-1986 (S86-61).

DNA. Multilocus G3382, Big Bend (S16-12), PR 79 at 25°C. Sister species are G. rubens and G. regularis (Gray et al. 2019) . See Gray et al. (2008) for results for many specimens east of our main study area. See also Blankers et al. (2018), which compared transcriptomic genetic variation in G. rubens and G. texensis . In that study, several loci were fixed for genetic differences between G. rubens and G. texensis , so in principle there are diagnostic genetic differences between these taxa, but they are not applicable in any practical sense.

Discussion. Probably the most common and widespread Gryllus species in Texas. Sympatric with G. rubens at Bastrop State Park, Texas (S91-23), and Lake Keystone State Park (S01-47) and Tulsa (S13-68) in Oklahoma. Sympatric with G. armatus at Texas localities of: Big Springs (S09-72); Big Bend (S91-43); Brackettville (S85-61 & S91-40); Monahans (S86-69); Alpine (S91-44); Van Horn (S91-48) and Kansas, Dodge City (S89-71). Microsympatric with both G. armatus and G. regularis at Alpine, Texas (S07-41).

We found males parasitized by tachinid Ormia ochracea from these Texas localities: 5 8 km E Del Rio on Hwy 90 (S86-49), Brownsville (S91-38), Bentsen-Rio Grande Valley State Park (S02-34), Schulenburg (S02-38), and Cameron Co. (S13-43). The Cade lab ( Cade et al. 1996, Gray & Cade 2000b) has done much work on Ormia parasitism of G. texensis in Texas.

Other published studies on G. texensis include those on sexual selection ( Gray & Cade 1999b, Gray & Cade 2000a, Bertram 2002a, b); aggression ( Sandford 1987), fine-scale temperature effects on calling song ( Martin et al. 2000) which demonstrated an increase in PR of 3.5 for every 1°C increase in recording temperature; influence of photoperiod on signaling ( Bertram & Bellani 2002); female cricket mating preferences ( Wagner et al. 1995, Blankers et al. 2015); life history trade-offs ( Guerra & Pollack 2007); hybridization studies ( Cade & Tyshenko 1990); predator-induced stress responses ( Adamo et al. 2013), courtship songs ( Fitzpatrick & Gray 2001); peripatric speciation ( Gray et al. 2008, Blankers et al. 2018); and interactions between temperature, reproduction and immune function ( Adamo & Lovett 2011).

Figures

FIGURE 71. Five second waveforms of calling songs of (A) G. rubens, (B) G. texensis, and (C) G. regularis. (A) G. rubens: (R13-220) Tulsa, OK (S13-68), at 25°C; (B) G. texensis: (R13-224) Rio Hondo, TX (S13-44), at 26°C; (C) G. regularis (R99- 211) Sinaloa, MX (S99-86), at 25.5°C.

FIGURE 72. One second spectrograms of (A) G. rubens, (B) G. texensis, and (C) G. regularis, same males as in Fig. 71.

FIGURE 73. ITS2 gene tree. G. rubens samples: Orlando, FL (F122); Lake City & Ocala, FL (Genbank SRA, Berdan et al. 2016); G. regularis samples: S07-2 (G1101); S07-41 (G1085); S15-67 (G3154); S15-102 (G3280); G. texensis samples: S15-43 (G3048); S16-12 (G3382, G3403, G3404, G3421); Uvalde, TX (d102); Bastrop, TX (d1042).

FIGURE 78. Regression of number file teeth vs. hind femur length showing separation of sympatric G. rubens from G. texensis.

FIGURE 79. Regression of number file teeth vs. teeth/mm showing separation of sympatric G. rubens from G. texensis.

FIGURE 82. Left: Regression of sympatric G. rubens and G. texensis from Tulsa, OK (S13-68) showing lack of separation in individuals for pulse rate vs. file teeth number. Right: Histogram of pulse rates of these same males.

FIGURE 83. Neotype male, G. texensis, specimen and labels.

FIGURE 84. One second waveform, pulse rate of 75, of calling song of G. texensis: (R13-224) Rio Hondo, TX (S13-44), at 26°C

FIGURE 85. Regression of file teeth number vs. hind femur in G. texensis vs. G. rubens showing overlap but lower number of teeth in latter.

FIGURE 86. Regression of pronotum width vs. ovipositor length in G. texensis vs. G. rubens showing generally shorter ovipositor length in former.

FIGURE 87. Regression of file teeth number vs. hind femur length in G. texensis vs. G. armatus showing overlap but generally more teeth in latter.

FIGURE 88. Populations of US G. texensis that we studied.

FIGURE 89. Color variation in G. texensis, both pictured individuals from Brackettville, TX (S10-63).

FIGURE 90. Regression of file teeth vs. teeth/mm showing separation of sympatric G. rubens from G. texensis.