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Publication #EENY069

Jamaican Field Cricket, Gryllus assimilis (Fabricius) (Insecta: Orthoptera: Gryllidae)1

Donald W. Hall and Jerry F. Butler2

Introduction

This species was first described from Jamaica and is widespread in the West Indies. It may have first become established in south Florida as recently as the early 1950’s. Its scientific name (Gryllus assimilis or Acheta assimilis) was applied to all New World field crickets until 1957.

Other Florida field and house crickets [May 9, 2012].

Distribution

In the United States, Jamaican field crickets are known only from south peninsular Florida and southernmost Texas.

Figure 1. 

Distribution of Jamaican field cricket in the United States.


[Click thumbnail to enlarge.]

Identification

Jamaican field crickets are not as dark as other Florida field crickets. The arms of the Y-shaped "ecdysial suture" [May 9, 2012] are well defined, and most of the areas around the eyes are light yellow-brown. The pronotum has a dense brown pubescence that makes this field cricket appear "fuzzier" than the other Florida species. All adults have long hind wings.

Figure 2. 

Jamaican field cricket, Gryllus assimilis (Fabricius), male.


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

Life Cycle

Jamaican field crickets probably occur in all stages at all times of year. Supporting this conjecture is the species’ tropical origin and its rapid, synchronous development in laboratory colonies. Its relatively large size and ease of rearing might make it competitive with the house cricket as a species to be reared and sold for pet food.

Habitat

This species is characteristic of lawns, weedy fields, roadsides and other open areas. It sometimes flies to lights in significant numbers. An African field cricket in which all adults are long-winged was found flying at sea more than 500 miles from shore. Thus it is possible that the Jamaican field cricket reached Florida from the West Indies under its own power.

Song

The calling song [May 9, 2012] (689 Kb wav file) of this species is a brief chirp repeated about once per second. Unlike Florida’s other chirping field crickets, each chirp usually has seven or more pulses, with the initial ones being briefer and more rapidly delivered than the terminal ones (graphs) [May 9, 2012]. The pulse rate is so high and the pulse intervals so brief that the chirp sounds more like a continuous sound than in other chirping species.

Selected References

  • Alexander RD, Walker TJ. 1962. Two introduced field crickets new to eastern United States (Orthoptera: Gryllidae). Annals of the Entomological Society of America 55: 90-94.

  • Walker TJ. (2011). Jamaican field cricket, Gryllus assimilis (Fabricius 1775). Singing Insects of North America. http://entnemdept.ifas.ufl.edu/walker/Buzz/487a.htm [1 August 2011].

Footnotes

1.

This document is EENY-069, 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. Revised: August 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.

2.

Donald W. Hall, professor; and Jerry F. Butler, 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.