Orthoptera of North Carolina
Scientific Name: Common Name:
Family (Alpha):
« »
View Gryllidae Members: NC Records

Allonemobius socius (Scudder, 1877) - Southern Ground Cricket



Micropterous female

Male

Macropterous female
Taxonomy
Family: Gryllidae Subfamily: Nemobiinae Tribe: PteronemobiiniSynonym: Nemobius fasciatus socius
Comments: One of ten species in this genus, all of which occur in North America north of Mexico (Cigliano et al., 2017). Eight species have been recorded in North Carolina.
Species Status: Originally described as a separate species from fasciatus by Scudder, who distinguished the two based primarily on the length of the ovipositor -- longer than the hind femur in fasciatus but less than or equal in socius (see key in Scudder, 1896). Hebard (1913) also noted this as a consistent difference but nonetheless downgraded socius to a subspecies of fasciatus, based on the otherwise preponderant similarities between the two forms. Alexander and Thomas (1959) went further still, dropping the subspecies designations and treating them both under the name fasciatus. Howard and Furth (1986) -- who appear to have had the last word -- also found no consistent differences in color or morphological features between socius and fasciatus, agreeing with Alexander and Thomas, but discovered significant differences using electrophoresis. Based on these findings, they restored socius to full species status, recognizing it now as a cryptic sibling of fasciatus.
Identification
Field Guide Descriptions: Capinera et al. (2004); Elliot and Hershberger (2006)Online Photographs: SINA, BugGuide, Songs of Insects, Google ImagesTechnical Description, Adults/Nymphs: Alexander and Thomas (1959); Howard and Furth (1986)SINA 532a.htm                                                                                  
Comments: A small, blackish to reddish-brown ground cricket. Currently separable from fasciatus -- which has not been documented in North Carolina (Howard and Waring, 1991) -- solely through use of electrophoresis, with a key based on allozymes provided by Howard and Furth (1986). Socius can be distinguished from other members of Allonemobius, however, based primarily by its strongly contrasting pattern of pale and dark stripes at the rear of the head. While these stripes are present in most species in this genus, they are usually far less contrasting than in socius or, in tinnulus, completely lacking.
Total Length [body plus wings; excludes ovipositor]: 8.2-10.1, males; 8.3-11.5, females (Howard and Furth, 1986; body lengths only, not including wings if longer than the abdomen)
Structural Features: Both micropterous (flightless) and macropterous forms exist in both sexes (Alexander and Thomas, 1959)
Singing Behavior: Songs consist of a series of chirps (short trills), very unlike the continuous trills of the allardi group or the slower, bell-like series of "tinks" of tinnulus. While somewhat similar to the series of chirps given by various species of Gryllus or Velarifictorus, they are much higher in pitch, with the dominant frequency above 8 kHz at 77 F (25 C) (SINA). Courtship songs may be even higher pitched, reaching frequencies above 9 kHz and with the chirp rate also increasing markedly.
Recording playback at normal speed.

Download Video: "MP4"

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: Associated with open, wet grassy areas, including early successional habitats dominated by Crabgrass and pond borders dominated by wetland graminoids; Fulton (1931) also reported it as occurring in lawns and pastures but not in drier grasslands.
Diet: Probably omnivorous
Observation Methods: One of the most easily observed ground crickets due to their high population densities and occurrence in open, low grass habitats. Songs are easily detected.
Abundance/Frequency: High density populations are regularly observed
Adult Phenology: Fulton (1931) reported that adults of socius emerge in June and may have as many as three broods each year
See also Habitat Account for General Wet Grasslands
Status in North Carolina
Natural Heritage Program Status:
Natural Heritage Program Ranks: [GNR] S5
State Protection: Has no legal protection, although permits are required to collect it on state parks and other public lands
Comments: Widespread, abundant, and associated with common habitats, including human-maintained grasslands. Appears to be very secure in North Carolina.

Image Gallery for Allonemobius socius - Southern Ground Cricket

Recorded by: Steve Hall and Bo Sullivan
Ashe Co.
Comment:
Recorded by: Simpson Eason
Durham Co.
Comment:
Recorded by: Ken Kneidel
Mecklenburg Co.
Comment:
Recorded by: Steve Hall and Bo Sullivan
Moore Co.
Comment:
Recorded by: Ken Kneidel
Yancey Co.
Comment:
Recorded by: Ken Kneidel
Scotland Co.
Comment:
Recorded by: Stephen Hall and Bo Sullivan
Moore Co.
Comment:
Recorded by: Jim Petranka
Madison Co.
Comment:
Recorded by: Mark Shields
Onslow Co.
Comment:
Recorded by: Mark Shields
Onslow Co.
Comment:
Recorded by: Steve Hall
Orange Co.
Comment: Macropterous female
Recorded by: Steve Hall
Iredell Co.
Comment:
Recorded by: Steve Hall and Bo Sullivan
Ashe Co.
Comment: Calling from grassy areas
Recorded by: Steve Hall
Orange Co.
Comment: Photographed and recorded in captivity (note reverberation from the walls of the container); temperature ~70 F. Captured in the same patch of habitat where males singing two different songs were recorded
Recorded by: Steve Hall
Orange Co.
Comment: Two different individuals singing in the same habitat patch (with a brief pause between recordings). The calling song is typical for this species, but higher pitched songs with a faster chirp and pulse rate have been heard at several locations where socius has been found.
Recorded by: Steve Hall and Bo Sullivan
Carteret Co.
Comment:
Recorded by: Stephen Hall and Bo Sullivan
Carteret Co.
Comment: Found at a site where both socius and fultoni were singing. The stripes on the head in this specimen appear to be lighter and more contrasting than those typical of fultoni.
Recorded by: Stephen Hall and Bo Sullivan
Carteret Co.
Comment:
Recorded by: Julie Tuttle
Orange Co.
Comment:
Recorded by: Stephen Hall and Ed Corey
Bladen Co.
Comment:
Recorded by: Stephen Hall
Orange Co.
Comment:
Recorded by: Stephen Hall
Orange Co.
Comment:
Recorded by: Stephen Hall
Orange Co.
Comment:

MP3 Gallery for Allonemobius socius - Southern Ground Cricket

1 Recorded by: Ken Kneidel
Mecklenburg Co.
2020-10-16
71 F, calling from the ground in a weedy area within a detention basin, dominant frequency 7.3 Hz
2 Recorded by: Jim Petranka
Madison Co.
2020-08-25
Individuals were calling along the edge of a pond in dense vegetation; air temp. ~ 75F; singing at > 8.0 kHZ.