Gryllus assimilis (Fabricius)

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 : 74-79

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/182387A8-0928-FFDC-51F6-F92405A3FD1D
treatment provided by	Plazi
scientific name	Gryllus assimilis (Fabricius)
status

Treatment

Jamaican Field Cricket

Figs 54 View FIGURE 54 , 60–66, Table 1 View TABLE 1

1775 Acheta assimilis . Systema Entomologiae, p. 280. Type from Jamaica lost, according to Alexander (1957). Neotype male ( Fig. 63 View FIGURE 63 ) selected by Weissman et al. 2009: Jamaica, St. Catherine Parish, Worthy Park, 27-xi-1968. T.J. Walker. Type deposited in CAS, Entomology Type #18172.

‘ Gryllus #1’, in part, of DBW notebooks. 2009 Gryllus assimilis Weissman et al. 2009 .

See Cigliano et al. (2019) for complete list of synonymies. Distribution. Texas and Florida only within the US.

Recognition characters and song. Always macropterous, although rare individuals apterous after shedding hind wings. Medium to large size ( Table 1 View TABLE 1 , p. 18), head frequently narrower than pronotum ( Fig. 64 View FIGURE 64 ), dorsal pronotal surface covered with short, fine hairs usually resulting in dull appearance. Song ( Fig. 65, R13-231, S13-44 View FIGURE 65 View FIGURE 13 View FIGURE 14 View FIGURE 15 View FIGURE 16 View FIGURE 17 View FIGURE 18 View FIGURE 19 View FIGURE 20 View FIGURE 21 View FIGURE 22 View FIGURE 23 View FIGURE 24 View FIGURE 25 View FIGURE 26 View FIGURE 27 View FIGURE 28 View FIGURE 29 View FIGURE 30 View FIGURE 31 View FIGURE 32 View FIGURE 33 View FIGURE 34 View FIGURE 35 View FIGURE 36 View FIGURE 37 View FIGURE 38 View FIGURE 39 View FIGURE 40 View FIGURE 41 View FIGURE 42 View FIGURE 43 View FIGURE 44 View FIGURE 45 View FIGURE 46 View FIGURE 47 View FIGURE 48 View FIGURE 49 View FIGURE 50 View FIGURE 51 View FIGURE View FIGURE 53 View FIGURE 54 View FIGURE 55 View FIGURE 56 View FIGURE 57 View FIGURE 58 View FIGURE 59 View FIGURE 60 View FIGURE 61 View FIGURE 62 View FIGURE 63 View FIGURE 64 View FIGURE 66 View FIGURE 67 View FIGURE 68 View FIGURE 69 View FIGURE 70 View FIGURE 71 View FIGURE 72 View FIGURE 73 View FIGURE 74 View FIGURE 75 View FIGURE 76 View FIGURE 77 View FIGURE 78 View FIGURE 79 View FIGURE 80 View FIGURE 81 View FIGURE 82 View FIGURE 83 View FIGURE 84 View FIGURE 85 View FIGURE 86 View FIGURE 87 View FIGURE 88 View FIGURE 89 View FIGURE 90 View FIGURE 91 View FIGURE 92 View FIGURE 93 View FIGURE 94 View FIGURE 95 View FIGURE 96 View FIGURE 97 View FIGURE 98 View FIGURE 99 View FIGURE 100 View FIGURE 101 View FIGURE 102 View FIGURE 103 View FIGURE 104 View FIGURE 105 View FIGURE 106 View FIGURE 107 View FIGURE 108 View FIGURE 109 View FIGURE 110 View FIGURE 111 View FIGURE 112 View FIGURE 113 View FIGURE 114 View FIGURE 115 View FIGURE 116 View FIGURE 117 View FIGURE 118 View FIGURE 119 View FIGURE 120 View FIGURE 121 View FIGURE 122 View FIGURE 123 View FIGURE 124 View FIGURE 125 View FIGURE 126 View FIGURE 127 View FIGURE 128 View FIGURE 129 View FIGURE 130 View FIGURE 131 View FIGURE 132 View FIGURE 133 View FIGURE 134 View FIGURE 135 View FIGURE 136 View FIGURE 137 View FIGURE 138 View FIGURE 139 View FIGURE 140 View FIGURE 141 View FIGURE 142 View FIGURE 143 View FIGURE 144 View FIGURE 145 View FIGURE 146 View FIGURE 147 View FIGURE 148 View FIGURE 149 View FIGURE 150 View FIGURE 151 View FIGURE 152 View FIGURE 153 View FIGURE 154 View FIGURE 155 View FIGURE 156 View FIGURE 157 View FIGURE 158 View FIGURE 159 View FIGURE 160 View FIGURE 161 View FIGURE 162 View FIGURE 163 View FIGURE 164 View FIGURE 165 View FIGURE 166 View FIGURE 167 View FIGURE 168 View FIGURE 169 View FIGURE 170 View FIGURE 171 View FIGURE 172 View FIGURE 173 View FIGURE 174 View FIGURE 175 View FIGURE 176 View FIGURE 177 View FIGURE 178 View FIGURE 179 View FIGURE 180 View FIGURE 181 View FIGURE 182 View FIGURE 183 View FIGURE 184 View FIGURE 185 View FIGURE 186 View FIGURE 187 View FIGURE 188 View FIGURE 189 View FIGURE 190 View FIGURE 191 View FIGURE 192 View FIGURE 193 View FIGURE 194 View FIGURE 195 View FIGURE 196 View FIGURE 197 View FIGURE 198 View FIGURE 199 View FIGURE 200 View FIGURE 201 View FIGURE 202 View FIGURE 203 View FIGURE 204 View FIGURE 205 View FIGURE 206 View FIGURE 207 View FIGURE 208 View FIGURE 209 View FIGURE 210 View FIGURE 211 View FIGURE 212 View FIGURE 213 View FIGURE 214 View FIGURE 215 View FIGURE 216 View FIGURE 217 View FIGURE 218 View FIGURE 219 View FIGURE 220 View FIGURE 221 View FIGURE 222 View FIGURE 223 View FIGURE 224 View FIGURE 225 View FIGURE 226 View FIGURE 227 View FIGURE 228 View FIGURE 229 View FIGURE 230 View FIGURE 231 ) loud, 6–9 (rarely 10) p/c, PR for first pulse pair ranges from 50 to 111, PR of last pair ranges from 40 to 83 ( Weissman et al. 2009). Chirps/second variable, but distinctive and usually <2.5 at 25°C. In the US, only native in southern Texas but introduced in southern Florida ( Alexander & Walker 1962). Probably continuous generations. Only sympatric Texas species (and then only in Brackettville (S10-63) and Big Bend (S16-12), TX) with a similar, but distinctive song is G. personatus , the latter having a faster chirp rate, a shiny pronotum, different microhabitat requirements, and different head and pronotum color patterns.

Derivation of name. “as” = a copper coin; “similis’ = like, resembling, perhaps with reference to an orange/reddish specimen that reminded Fabricius of the color of a copper coin.

Geographic range. ( Fig. 66 View FIGURE 66 ). Native in southern Texas, introduced in Florida ( Alexander & Walker 1962). Fieldwork in 2013 in southern coastal Texas uncovered a much wider distribution than seen in previous years ( Weissman et al. 2009). Ranges through Mexico and Central America, usually east of the Continental Divide. On many Caribbean Islands ( Otte & Perez-Gelabert 2009, Weissman et al. 2019), and possibly into South America ( Weissman et al. 2009). Widespread sale of this cricket species by US pet-feeder suppliers raises the possibility that feral populations could be established outside its normal US-North American distribution ( Weissman et al. 2012). Barranco (2012) claims feral populations of G. assimilis in Spain but doesn’t supply an oscillogram to confirm identification. We believe those crickets could be G. locorojo ( Weissman et al. 2012) .

Habitat. Almost always associated with people and their watered environs such as lawns, golf courses, school grounds, and in towns. Usually in mowed grassy areas and sometimes in holes.

Life cycle and seasonal occurrence. Diapause unknown for any stage of development. Probably 2 or 3 generations/year with overlap of the continuous generations. Collected early June to mid-September, but obviously present at other times of the year.

Variation. Color: Head, pronotum, body, tegmina, and legs from black to tan ( Fig. 64 View FIGURE 64 ). As we have not seen winter/spring individuals, we may be missing darker colored individuals.

Specimens examined. Texas: Bastrop Co., Smithville, 325’, late September. S.M. Bertram. Brazoria Co., Farm Road 521 5.5 m SE Brazoria , 38’, 13-vii-2013 (S13-61). Brewster Co., Big Bend National Park, Rio Grande Village, 1860’, 28-v-2016, (S16-12). Calhoun Co., Port Lavaca, 18’, 12-vii-2013 (S13-57). Cameron Co., Brownsville, sea level, 3-vi-1991 (S91-38). 3.1 m W Boca Chica State Park on Hwy 4, 10-vi-2007 (S07-26). Rio Hondo, 8m, 10-vii- 2013 (S13-44). Intersection Farm Roads 510 and 2480. 2m, 10-vii-2013 (S13-43). Fayette Co., 2 m S Schulenburg, 440’, 9-ix-2010 (S10-65). Schulenburg, 460’, 9-ix-2010 (S10-66); 14-vii-2013 (S13-66). Hidalgo Co., Benson Rio Grande State Park, sea level, 3-viii-2002 (S02-34); 10-vi-2007 (S07-27). Jim Wells Co., Alice, 171’, 11-vii-2013 (S13-48, 49, 50). Kinney Co., Brackettville, 1160’, 7-ix, 2010 (S10-63). Nueces Co., Corpus Christi, sea level, 11- vi-2011 (S11-36); 12-vii-2013 (S13-53). Refugio Co., Tivoli, 12’, 12-vii-2013 (S13-56). Val Verde Co., Del Rio, 1140’, 7-ix-2012 (S10-64). Victoria Co., Victoria, 20’, 4-viii-2007 (S02-37). Willacy Co., Raymondville, 10-vii- 2013 (S13-47). Farm Road 1420 near intersection FR 498, 15’, 10-vii-2013 (S13-46).

DNA. G3373 (Big Bend, TX [S16-12]) in multilocus species tree (Gray et al. 2019); G. multipulsator is closest DNA relative, at least within our study area. DNA data from a more extensive series is presented in Weissman et al. 2009.

Discussion. In Texas, before 2013, we found this species generally uncommon and dispersed, which contrasts with the situation along the east coast of Mexico where G. assimilis is more common. For unknown reasons, collecting in coastal Texas in 2013 uncovered several dense populations and much wider distributions than in previous years. This cricket is loud and singing males are not easily overlooked. Perhaps because of its adaptation to lowland, cool coastal habitats, G. assimilis males still sing well at 04:00 when most other Gryllus species have long ceased singing.

Bertram & Rook (2011a, b) have studied calling songs and biological aspects in this species from the Austin, Texas area, while Pollack & Kim (2013) and Vedenina & Pollack (2012) studied female phonotaxis and variable courtship song in long-term laboratory cultures. Sturm (2014) and Villarreal et al. (2018) examined aspects of mating strategies. Weissman et al. (2012) documented efforts by US and European cricket farms to utilize another Gryllus species, G. locorojo , misidentified as G. assimilis , to replace virus-infected Acheta domesticus as the preferred pet-feeder cricket.

S.M. Bertram notes (pers. comm. to T.J. Walker, March, 2015) that she and her group have encountered thousands of flying individuals at lights in the fall around Smithville, Bastrop Co., TX, in 2007, 2008 or 2009, and 2014. This situation seems similar to those outbreaks described by Alexander & Walker (1962) in Florida.