Orthoptera of North Carolina

Family (Alpha):

View	Gryllidae Members:	NC Records
Gryllus firmus Scudder, 1902 - Sand Field Cricket

Adult female

Taxonomy

Family: Gryllidae	Subfamily: Gryllinae	Tribe: Gryllini	Synonym: Acheta firma, Gryllus assimilis firmus
Comments: One of eighteen species in this genus that occur in North America north of Mexico (Weissman and Gray, 2019), five of which have been recorded in North Carolina.
Species Status: Specimens from North Carolina were mentioned by Scudder (1902) in his description of this species, but it is not clear whether they represented the type specimens. Alexander (1957) identified the specimens from Pungo Bluff as lectotypes and OSF recognized North Carolina specimens as syntypes.

Identification

Field Guide Descriptions: Capinera et al. (2004; not illustrated); Himmelman (2009)	Online Photographs: SINA; BugGuide, Google Images, iNaturalist, GBIF	Technical Description, Adults/Nymphs: Scudder (1902); Alexander (1957)	SINA 481a.htm
Comments: This is the largest member of this genus in our area. Adults have shining black heads, thorax, and abdomen; wings are usually contrastingly yellow-brown (Scudder, 1902; Himmelman, 2009).
Total Length [body plus wings; excludes ovipositor]: 27 mm, males; 26 mm, females (Scudder, 1902)
Structural Features: Pronotum is widest towards the anterior and the head of the male is typically wider than the pronotum (Alexander, 1957); the body length is usually over 18 mm, whereas it is usually shorter in all other North Carolina species of Gryllus.
Singing Behavior: Songs consist of the classic Gryllus series of chirps, with each chirp composed of 4-6 pulses and the chirps given at a rate of 1-3 per second at 85 degrees F (Alexander, 1957). The chirp rate is the slowest of the species that occur in North Carolina, including pennsylvanicus, which may or may not overlap with firmus in the eastern Piedmont. The dominant frequency is around 3.6 kHz at 77 degrees F (=24.8 C) (SINA, 2017).
Recording playback at normal speed.
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Nymphal Stages and Development: Nymphs overwinter (Fulton, 1952)

Distribution in North Carolina


County Map: Clicking on a county returns the records for the species in that county.


Adult Dates: High Mountains (HM) ≥ 4,000 ft. Low Mountains (LM) < 4,000 ft. Piedmont (Pd) Coastal Plain (CP) Click on graph to enlarge

Habitats and Life History

Habitats: Strongly associated with sandy soils. Fulton (1952) described the habitat of his "beach cricket" as sandy, treeless areas along the coast. Alexander (1968) described an inland population associated with sandhills at Spout Springs and Hall and Corey recorded a population at Singletary Lake associated with a xeric Carolina bay rim, dominated by Longleaf Pines and xerophytic oaks.

Diet: Probably omnivorous

Observation Methods: Mostly easily detected by its song, which is given both day and night

Abundance/Frequency: Can be common but with singing males somewhat spread apart

Adult Phenology: A few adults appear to emerge in June but become most numerous in late summer and fall, persisting until the end of November (Fulton, 1952). Fulton also reported hearing a single male singing on May 13th.

See also Habitat Account for General Fire-maintained Sandhills

Status in North Carolina

Natural Heritage Program Status:

Natural Heritage Program Ranks: [GNR S4S5]

State Protection: Has no legal protection, although permits are required to collect it on state parks and other public lands

Comments: This species is at least somewhat restricted in terms of habitats but the degree to which it requires natural sand ridges is unknown. One population has been reported to be extirpated due to conversion of its habitat to a pine plantation (Alexander, 1968), so it may be at least somewhat vulnerable to habitat loss and fragmentation. More information is needed on its presence in sandy old fields or other agricultural lands before its conservation status in North Carolina can be accurately determined.

Image Gallery for Gryllus firmus - Sand Field Cricket
	Recorded by: Mark Basinger Wilson Co. Comment:	Recorded by: Mark Basinger Wilson Co. Comment:
	Recorded by: Mark Basinger Wilson Co. Comment:	Recorded by: Mark Basinger Brunswick Co. Comment:
	Recorded by: Mark Basinger, Jim Petranka, and Becky Elkin Moore Co. Comment:	Recorded by: Stephen Hall Richmond Co. Comment:
	Recorded by: Steve Hall, Laurie Hamon, Carol Tingley, Tom Howard, and Pat Coin Moore Co. Comment:	Recorded by: Mark Basinger, Jim Petranka, and Becky Elkin Richmond Co. Comment:
	Recorded by: Mark Basinger Carteret Co. Comment:	Recorded by: Mark Basinger Carteret Co. Comment:
	Recorded by: Mark Basinger Richmond Co. Comment:	Recorded by: Mark Basinger Richmond Co. Comment:
	Recorded by: Mark Basinger Scotland Co. Comment:	Recorded by: Mark Basinger Scotland Co. Comment:
	Recorded by: Mark Basinger Rowan Co. Comment:	Recorded by: John Petranka, Jim Petranka Dare Co. Comment:
	Recorded by: John Petranka, Jim Petranka Dare Co. Comment:	Recorded by: Steve Hall and Bo Sullivan Moore Co. Comment:
	Recorded by: R. Newman Carteret Co. Comment:	Recorded by: Steve Hall and Bo Sullivan Moore Co. Comment:
	Recorded by: Ken Kneidel Scotland Co. Comment:	Recorded by: Ken Kneidel Scotland Co. Comment:
	Recorded by: Stephen Hall Moore Co. Comment:	Recorded by: Stephen Hall Moore Co. Comment:
	Recorded by: Stephen Hall Moore Co. Comment:	Recorded by: Steve Hall New Hanover Co. Comment: Calling along the ecotone of a sand ridge and riverine marsh; sunny but a cold front came through this morning and the temperatures were in the low to mid-60s; fairly windy
	Recorded by: Steve Hall Bladen Co. Comment: Recorded using DSLR video	Recorded by: Newman, Randy Carteret Co. Comment:

Gryllus firmus Scudder, 1902 - Sand Field Cricket

Image Gallery for Gryllus firmus - Sand Field Cricket