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Genus Gryllus

field crickets

link to keys Key to genera of field crickets (Gryllinae).

Species of the genus Gryllus (field crickets) are the most-studied of North American singing insects. They are large, easy to rear and handle, and diverse in their acoustic behavior, ecology, and life cycles. Their early taxonomic history is instructive. Many species were described in the 1800s, but when Rehn and Hebard (1915) intensively analyzed 1,500 pinned Western Hemisphere specimens, they concluded that all native American Gryllus belonged to a single "exceedingly plastic" species, Gryllus assimilis. This conclusion held for more than 30 years, until B. B. Fulton (1952) studied, in the field and in captivity, living Gryllus in North Carolina. He showed there were four reproductively isolated populations that differed in their calling songs, habitats, and seasonal life cycles. Because he found no defining morphological differences, Fulton did not give scientific names to the species he had discovered. R. D. Alexander (1957) extended Fulton’s studies of Gryllus to the Midwest, found a fifth species, and showed that most species pairs were separable by morphological characters, at least in one sex. He assigned scientific names, thus confronting museum curators with the fact that their trays of Gryllus assimilis probably contained mixtures of species none of which was likely to be G. assimilis. More importantly, differentiating and naming species of North American Gryllus made them inviting subjects for studies of evolution, behavior, and physiology.

From 1957 until 2019, seven more Gryllus species were described from the United States north of Mexico. In 2019, David Weissman and David Gray published a monograph on U.S. Gryllus that validated 18 previously described species and described 17 species as new.

Calling songs and life histories are still the predominant means of recognizing new species of Gryllus. Once a new species is recognized, morphological differences may be easy or difficult to find.

Seasonal life cycles

Species of Gryllus from the same geographic locality may have very different seasonal life histories. In fact, the two most abundant field crickets in the Northeast are separable chiefly by their life histories. Gryllus veletis and G. pennsylvanicus (spring and fall field crickets) do not differ in song or habitat and differ morphologically only in the average length of the ovipositor relative to the body length. However, G. veletis overwinters as mid-sized juveniles and matures in spring, whereas G. pennsylvanicus overwinters as eggs and matures in fall. The two species co-occur as adults, in very small numbers, only briefly in midsummer. Thus, except for the occasional specimen collected during the period of overlap, the date of collection is sufficient to distinguish adults of the two species.

G. veletis and G. pennsylvanicus, like many other Gryllus, have a single annual generation. Some species have two discrete generations per year (e.g., G. rubens) and others have generations that overlap (e.g. G. assimilis). G. firmus in Gainesville, Florida, has remarkably varied responses to seasons. It overwinters in all stages except small juveniles, and the eggs of a single female may hatch over a five-month period and the resulting juveniles may mature over a nine month period!

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Representative life cycles Asynchronous development

Phylogeny

The evolutionary branching sequence (phylogeny) that produced the species of North American field crickets is important to those wishing to understand the evolution of the differences among the species. For example, the similarity of G. pennsylvanicus and G. veletis, except in their seasonal life cycles, led to the assumption that the two were sister species and to a theory of how the ancestral species might have produced the two species sympatrically by allochronic speciation (Alexander and Bigelow 1960). Subsequently, studies of chromosomes, allozymes, and mitochondrial DNA indicated that the split between egg and juvenile-overwintering species occurred early in the phylogeny of North American Gryllus and that G. pennsylvanicus and G. veletis were on different branches of the Gryllus family tree.








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Phylogenetic charts from Huang et al. 2000 (left) and Gray et al. 2020 (right).

Huang et al. (2000) reconstructed the phylogeny of ten species of North American Gryllus based on the DNA sequences of two mitochondrial genes. Trios of closely related species were firmus-ovisopis-pennsylvanicus, texensis-rubens-lineaticeps, and fultoni-integer-veletis.

Gray et al. (2020) published a comprehensive molecular phylogeny of North American Gryllus that mostly used material collected by Dave Weissman in preparing his and Dave Gray’s monograph (2019) of U.S. Gryllus. The monograph included descriptions of 17 new species, all with type localities west of the Mississippi River. These new species made a phylogeny that was more complex as well as more lengthy than the one by Huang et al. 2000. Nonetheless, for three species of special interest (firmus, ovisopis, and pennsylvanicus), the branching is essentially the same.


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The excerpt at left shows “clade 3” of the four clades of North American Gryllus recognized by Huang et al. (2000). The excerpt at right shows a clade consisting of G. ovisopis and G. thinos and a related clade consisting of G. pennsylvanicus and G. firmus. In their classification of Gryllus spp., Weissman & Gray (2019) made these two clades the Ovisopis Group and the Pennsylvanicus Group respectively. To learn what is important about the Pennsylvanicus Group, go to the explanation of the last image of the G. firmus page.

References

Alexander RD. 1957. The taxonomy of the field crickets of the eastern United States (Orthptera: Gryllidae: Acheta). Ann. Entomol. Soc. Am. 50: 584-602.

Alexander RD, Bigelow RS. 1960. Allochronic speciation in field crickets, and a new species, Acheta veletis. Evolution 14: 334-346.

Alexander RD, Meral GH. 1967. Seasonal and daily chirping cycles in the northern spring and fall field crickets Gryllus veletis and G. pennsylvanicus. Ohio J. Sci. 67: 200-209.

Alexander RD, Walker TJ. 1962. Two introduced field crickets new to eastern United States (Orthoptera, Gryllidae). Ann. Entomol. Soc. Am. 55(1): 90-94. [Gryllus assimilis, Velarifictorus micado]

Backus VL, Cade WH. 1986. Sperm competition in the field cricket Gryllus integer (Orthoptera: Gryllidae). Fla. Entomol. 69: 722-728. [=Gryllus texensis]

Bertram SM. 2000. The influence of age and size on temporal mate signalling behaviour. Anim. Behav. 60: 333-339. [Gryllus texensis]

Bigelow RS. 1958. Evolution in the field cricket Acheta assimilis Fab. Can. J. Zool. 36: 139-151. [=Gryllus spp.]

Bigelow RS. 1960a. Developmental rates and diapause in Acheta pennsylvanicus (Burmeister) and Acheta veletis Alexander and Bigelow (Orthoptera: Gryllidae). Can. J. Zool. 38: 973-988.

Bigelow RS. 1960b. interspecific hybrids and speciation in the genus Acheta (Orthoptera Gryllidae). Can. J. Zool. 38: 509-524. [=Gryllus spp.]

Cade WH. 1979. Effect of male-deprivation on female phonotaxis in field crickets (Orthoptera, Gryllidae; Gryllus). Can. Entomol. 111: 741-744. [Gryllus veletis and G. texensis]

Cade WH. 1981a. Field cricket spacing, and the phonotaxis of crickets and parasitoid flies to clumped and isolated cricket songs. Z. Tierpsychol. 55: 365-375. [Gryllus veletis and G. texensis]

Cade WH. 1981b. Alternative male strategies: Genetic differences in crickets (Gryllus integer). Science 212: 563-564. [=Gryllus texensis]

Cade WH. 1984. Effects of fly parasitoids on nightly calling duration in field crickets (Gryllus integer). Can. J. Zool. 62: 226-228. [=Gryllus texensis]

Cade WH. 1989. Nightly and hourly rates of attraction of flying field crickets, Gryllus integer, to conspecific song. Can. J. Zool. 67: 2540-2542. [=Gryllus texensis]

Cade WH. 1991. Interspecific and intraspecific variation in nightly calling duration in field crickets, Gryllus integer and Gryllus rubens (Orthoptera: Gryllidae). J. insect Behav. 4: 185-194. ["Gryllus integer"= G. texensis]

Cade WH, Cade ES. 1992. Male mating success, calling and searching behaviour at high and low densities in the field cricket, Gryllus integer. Anim. Behav. 43: 49-56. [=Gryllus texensis]

Cade WH, Ciceran M, Murray AM. 1996. Temporal patterns of parasitoid fly (Ormia ochracea) attraction to field cricket song (Gryllus integer). Can. J. Zool. 74: 393-395. [=Gryllus texensis]

Cade WH, Otte D. 2000. Gryllus texensis n. sp.: a widely studied field cricket (Orthoptera; Gryllidae) from the southern United States. Trans. Am. Entomol. Soc. 126: 117-123.

Cade WH, Tyshenko MG. 1990. Geographic variation in hybrid fertility in the field crickets Gryllus integer, Gryllus rubens, and Gryllus sp. Can. J. Zool. 68: 2697-2700. ["Gryllus sp."= G. texensis]

Cade WH, Wyatt DR. 1984. Factors affecting calling behavior in field crickets, Teleogryllus and Gryllus: Age, weight, density and parasites. Behaviour 88: 61-75. [G. texensis, G. pennsylvanicus, G. veletis]

Carriere Y, Roff DA. 1995. The evolution of offspring size and number: A test of the Smith-Fretwell model in three species of crickets. Oecologia 102: 389-396. [Gryllus firmus, G. veletis, G. pennsylvanicus]

Carriere Y, Simons AM, Roff DA. 1996. The effect of the timing of post-diapause egg development on survival, growth, and body size in Gryllus pennsylvanicus. Oikos 75: 463-470.

Ciceran M, Murray AM, Rowell G. 1994. Natural variation in the temporal patterning of calling song structure in the field cricket Gryllus pennsylvanicus: Effects of temperature, age, mass, time of day, and nearest neighbour. Can. J. Zool. 72: 38-42.

Dixon KA, Cade WH. 1986. Some factors influencing male-male aggression in the field cricket Gryllus integer (time of day, age, weight and sexual maturity). Anim. Behav. 34: 340-346. [=Gryllus texensis]

Doherty JA, Callos JD. 1991. Acoustic communication in the trilling field cricket, Gryllus rubens (Orthoptera: Gryllidae). J. insect Behav. 4: 67-82.

Doherty JA, Storz MM. 1992. Calling song and selective phonotaxis in the field crickets, Gryllus firmus and Gryllus pennsylvanicus (Orthoptera: Gryllidae). J. insect Behav. 5: 555-569.

Farris HE, Forrest TG, Hoy RR. 1998. The effect of ultrasound on the attractiveness of acoustic mating signals. Physiol. Entomol. 23: 322-328. [Gryllus rubens]

Fitzpatrick MJ, Gray DA. 2001. Divergence between the courtship songs of the field crickets Gryllus texensis and Gryllus rubens (Orthoptera: Gryllidae). Ethology 107: 1075-1085.

French BW, Cade WH. 1987. The timing of calling, movement, and mating in the field crickets Gryllus veletis, Gryllus pennsylvanicus, and Gryllus integer. Behav. Ecol. Sociobiol. 21: 157-162.["G. integer" = G. texensis]

French BW, Cade WH. 1989. Sexual selection at varying population densities in male field crickets, Gryllus veletis and Gryllus pennsylvanicus. J. insect Behav. 2: 105-122.

Fulton BB. 1952. Speciation in the field cricket. Evolution 6:283-95.

Giordano R, Jackson JJ, Robertson HM. 1997. The role of Wolbachia bacteria in reproductive incompatibilities and hybrid zones of Diabrotica beetles and Gryllus crickets. Proc. Natl. Acad. Sci. USA 94: 11439-11444.

Gray DA, Cade WH. 1999. Quantitative genetics of sexual selection in the field cricket, Gryllus integer. Evolution 53: 848-854. [=Gryllus texensis]

Gray DA, Cade WH. 1999. Sex, death and genetic variation: Natural and sexual selection on cricket song. Proc. R. Soc. Biol. Sci. Ser. B 266: 707-709. [Gryllus texensis]

Gray DA, Cade WH. 2000. Sexual selection and speciation in field crickets. PNAS 97: 14449-14454. [Gryllus texensis and G. rubens]

Gray DA, Walker TJ, Conley BE, Cade WH. 2001. A morphological means of distinguishing females of the cryptic field cricket species, Gryllus rubens and G. texensis (Orthoptera: Gryllidae). Fla. Entomol. 84: 314-315.

Gray DA, Weissman DB, Cole JA, Lemmon EM, Lemmon AR. 2020. Multilocus phylogeny of Gryllus field crickets (Orthoptera: Gryllidae: Gryllinae) utilizing anchored hybrid enrichment. Zootaxa 4750(3): 328-348.

Gurney AB. 1950. Entomology--The Linnaean subgeneric names of Gryllus (Orthoptera). J. Wash. Acad. Sci. 40: 409-413.

Harrison RG. 1979. Flight polymorphism in the field cricket Gryllus pennsylvanicus. Oecologia 40: 125-132.

Harrison RG. 1979. Speciation in North American field crickets: Evidence from electrophoretic comparisons. Evolution 33: 1009-1023.

Harrison RG, Arnold J. 1982. A narrow hybrid zone between closely related cricket species. Evolution 36: 535-552. [Gryllus pennsylvanicus and G. firmus]

Harrison RG. 1983. Barriers to gene exchange between closely related cricket species: 1. Laboratory hybridization studies. Evolution 37: 245-251. [Gryllus pennsylvanicus and G. firmus]

Harrison RG. 1985. Barriers to gene exchange between closely related cricket species: 2. Life cycle variation and temporal isolation. Evolution 39: 244-259. [Gryllus pennsylvanicus and G. firmus]

Harrison RG. 1986. Pattern and process in a narrow hybrid zone. Heredity 56: 337-350. [Gryllus pennsylvanicus and G. firmus]

Harrison RG, Rand DM, Wheeler WC. 1987. Mitochondrial DNA variation in field crickets across a narrow hybrid zone. Mol. Biol. Evol. 4: 144-158. [Gryllus pennsylvanicus and G. firmus]

Harrison RG, Bogdanowicz SM. 1995. Mitochondrial DNA phylogeny of North American field crickets: perspectives on the evolution of life cycles, songs, and habitat associations. J. Evol. Biol. 8: 209-232.

Harrison RG, Bogdanowicz SM. 1997. Patterns of variation and linkage disequilibrium in a field cricket hybrid zone. Evolution 51: 493-505.

Hedrick AV. 1986. Female preferences for male calling bout duration in a field cricket (Gryllus integer). Behav. Ecol. Sociobiol. 19: 73-77.

Hedrick AV. 1988. Female choice and the heritability of attractive male traits: An empirical study. Am. Nat. 132: 267-276. [Gryllus integer]

Hedrick A, Weber T. 1998. Variance in female responses to the fine structure of male song in the field cricket, Gryllus integer. Behav. Ecol. 9: 582-591.

Hedrick AV. 2000. Crickets with extravagant mating songs compensate for predation risk with extra caution. Proc. R. Soc. Biol. Sci. Ser. B 267: 671-675. [Gryllus integer]

Hoback WW, Wagner WE, Jr. 1997. The energetic cost of calling in the variable field cricket, Gryllus lineaticeps. Physiol. Entomol. 22: 286-290.

Holtmeier CL, Zera AJ. 1993. Differential mating success of male wing morphs of the cricket, Gryllus rubens. Am. Midl. Nat. 129: 223-233.

Huang Y, Ortí G, Sutherlin M, Duhachek A, Zera A. 2000. Phylogenetic relationships of North American field crickets inferred from mitochondrial DNA data. Molecular Phylogenetics and Evolution 17(1): 48-57.

Ibrahim R, Walker TJ. 1980. Diapause and nondiapause eggs laid daily by individual Gryllus firmus females (Orthoptera: Gryllidae).  Fla. Entomol. 63(4): 510-512.

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Online First, DOi 10.1007/s00265-005-0151-3, URL http://dx.doi.org/10.1007/s00265-005-0151-3

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Murray AM, Cade WH. 1995. Differences in age structure among field cricket populations (Orthoptera: Gryllidae): Possible influence of a sex-biased parasitoid. Can. J. Zool. 73: 1207-1213. [Gryllus veletis, G. pennsylvanicus, G. texensis]

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Smith CJ, Cade WH. 1987. Relative fertility in hybridization experiments using three song types of the field crickets Gryllus integer and Gryllus rubens. Can. J. Zool. 65: 2390-2394. [+ G.texensis]

Souroukis K, Cade WH, Rowell G. 1992. Factors that possibly influence variation in the calling song of field crickets: Temperature, time, and male size, age, and wing morphology. Can. J. Zool. 70: 950-955. [Gryllus texensis]

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Wagner WE, Jr., Murray AM, Cade WH. 1995. Phenotypic variation in the mating preferences of female field crickets, Gryllus integer. Anim. Behav. 49: 1269-1281. [= Gryllus texensis]

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Walker TJ. 1987. Wing dimorphism in Gryllus rubens, Orthoptera: Gryllidae. Ann. Entomol. Soc. Am. 80: 547-560.

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Walker TJ. 2000. Pulse rates in the songs of trilling field crickets (Orthoptera: Gryllidae: Gryllus). Ann. Entomol. Soc. Am. 93: 565-572. [Gryllus rubens and G. texensis]

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