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Publication #EENY066

Sand Field Cricket, Gryllus firmus Scudder (Insecta: Orthoptera: Gryllidae)1

T. J. Walker2

Introduction

This species is the common chirping field cricket of lawns, pastures, and roadsides throughout Florida.

For information on other Florida field and house crickets see: http://entomology.ifas.ufl.edu/creatures.

Distribution

Sand field crickets occur throughout the southeastern United States. To the north and west the species is replaced by the fall field cricket (Gryllus pennsylvanicus). In areas of contact the two hybridize to a minor extent.

Figure 1. 

Distribution of sand field cricket in the United States.


[Click thumbnail to enlarge.]

Identification

The sand field cricket and the southeastern or southwestern field cricket often occur together and may be difficult to distinguish except by song. The easiest morphological means of telling the two apart is the color pattern on the forewings (http://entomology.ifas.ufl.edu/creatures). For males, the number and spacing of the teeth in the stridulatory file (http://entomology.ifas.ufl.edu/creatures) is definitive.

Figure 2. 

Sand field cricket, Gryllus firmus (Scudder), short-winged male.


Credit: Paul M. Choate, University of Florida
[Click thumbnail to enlarge.]

Figure 3. 

Sand field cricket, Gryllus firmus (Scudder), short-winged female.


Credit: Paul M. Choate, University of Florida
[Click thumbnail to enlarge.]

In southern Florida, where sand and Jamaican field crickets co-occur, the color pattern of the head (http://entomology.ifas.ufl.edu/creatures) will separate the two.

Life Cycle

Sand field crickets have the most variable life cycle known for field crickets. During much of the year females lay some eggs that hatch within a few weeks at room temperatures and other eggs that take a month or two to hatch under the same conditions. Furthermore, if potentially quick-hatching eggs are exposed to cool temperatures, some lose that potential. Nymphal development is also variable with some developing quickly and some much more slowly, even when exposed to the same conditions. The effect of all this is that a female s progeny may mature over a 10-month period, with slow developers maturing at the same time as some of the progeny of their faster-developing sibs. In spite of the variability, there are peaks of adults in late spring (mostly from over-wintering eggs) and in fall (mostly from fast-developing progeny of spring adults).

Habitat

This species is characteristic of lawns, pastures, and roadsides, especially those that are well drained and sandy.

Song

The calling song (689Kb wav file) is a series of slow-pulsed chirps, with a chirp rate of about two per second. Most chirps have four pulses, with the initial one being much weaker than the rest (graphs).

Selected References

Crnokrak, P., and D. A. Roff. 1995. Fitness differences associated with calling behaviour in the two wings morphs of male sand crickets, Gryllus firmus. Animal Behavior 50: 1475-1481.

Harrison, R. G. 1986. Pattern and process in a narrow hybrid zone. Heredity. 56: 337-350.

Harrison, R. G., and S. M. Bogdanowicz. 1997. Patterns of variation and linkage disequilibrium in a field cricket hybrid zone. Evolution. 51: 493-505.

Pires, A., and R. R. Hoy. 1992. Temperature coupling in cricket acoustic communication: I. Field and laboratory studies of temperature effects on calling song production and recognition in Gryllus firmus. J. Comp. Physiol. A Sens. Neural Behav. Physiol. 171: 69-78.

Roff, D. A., and D. J. Fairbairn. 1993. The evolution of alternate morphologies: Fitness and wing morphology in male sand crickets. Evolution 47: 1572-1584.

Walker, T. J. 1980. Mixed oviposition in individual females of Gryllus firmus: Graded proportions of fast-developing and diapause eggs. Oecologia (Berlin) 47: 291-298

Walker, T. J. 1986. Monitoring the flights of field crickets (Gryllus spp.) and a tachinid fly (Euphasiopteryx ochracea) in north Florida (USA). Florida Entomologist 69: 678-685

Walker T. J. (2011). Sand field cricket, Gryllodes firmus Scudder 1902. Singing Insects of North America. http://entnemdept.ifas.ufl.edu/walker/Buzz/501a.htm (23 September 2011).

Zera, A. J., J. Sall, and K. Grudzinski. 1997. Flight-muscle polymorphism in the cricket Gryllus firmus: Muscle characteristics and their influence on the evolution of flightlessness. Physiological Zoology 70: 519-529.

Footnotes

1.

This document is EENY-066, one of a series of Featured Creatures from the Entomology and Nematology Department, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. Published: January 1999. Reviewed: March 2011. This document is also available on Featured Creatures website at http://entomology.ifas.ufl.edu/creatures. Please visit the EDIS website at http://edis.ifas.ufl.edu. Additional information on these organisms, including many color photographs, is available at the Entomology and Nematology Department website at http://entnemdept.ifas.ufl.edu/.

2.

T. J. Walker, professor, Entomology and Nematology Department, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, 32611.


The Institute of Food and Agricultural Sciences (IFAS) is an Equal Opportunity Institution authorized to provide research, educational information and other services only to individuals and institutions that function with non-discrimination with respect to race, creed, color, religion, age, disability, sex, sexual orientation, marital status, national origin, political opinions or affiliations. For more information on obtaining other UF/IFAS Extension publications, contact your county's UF/IFAS Extension office.

U.S. Department of Agriculture, UF/IFAS Extension Service, University of Florida, IFAS, Florida A & M University Cooperative Extension Program, and Boards of County Commissioners Cooperating. Nick T. Place, dean for UF/IFAS Extension.