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

Allonemobius tinnulus (Fulton, 1931) - Tinkling Ground Cricket

Allonemobius tinnulus
Female
Taxonomy
Family: Gryllidae Subfamily: Nemobiinae Tribe: PteronemobiiniSynonym: Nemobius tinnulus
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: First described as a subspecies of fasciatus by Fulton (1931), based on a specimen collected in Raleigh. Raised to full species status by Alexander and Thomas (1959).
Identification
Field Guide Descriptions: Capinera et al. (2004, not illustrated); Elliot and Hershberger (2006); Himmelman (2009)Online Photographs: BugGuide, SINA, Google Images,  iNaturalist, GBIFTechnical Description, Adults/Nymphs: Fulton (1931); Howard and Furth (1986)SINA 530a.htm                                                                                  
Comments: Fulton described tinnulus as tawny, with the head and pronotum cinnamon brown; the stripes on the head are faint or absent. Other members of the fasciatus group are darker or more strongly striped on the rear of the head (Alexander and Thomas, 1959; Howard and Furth, 1986). In females, the abdomen is buffy brown with a blackish median stripe; in males, the abdomen is nearly all black (Fulton, 1931).
Total Length [body plus wings; excludes ovipositor]: 8.1-9.2 mm, males; 9.0-10.2, females (Howard and Furth, 1986)
Structural Features: Only micropterous (flightless) individuals have been observed (Fulton, 1931; Alexander and Thomas, 1959; Thomas and Furth, 1986)
Singing Behavior: Fulton (1931) described the song of tinnulus as consisting of a series of "sharp, metallic chirps, with constant rhythm, 6-9 per second". The dominant frequency ranges between 7 and 7.7 kHz at warm temperatures (Elliot and Hershberger, 2006; SINA, 2017). Other species with similar tinkling songs include Allonemobius allardi, A. walkeri, A. fultoni, and Anaxipha tinnulacita, but all have a faster pulse rate at a given temperature than tinnulus (Howard and Furth, 1986; Walker and Funk, 2014). Anaxipha tinnulenta -- the Slow-tinkling Trig -- however, can be easily confused with A. tinnulus, as recognized by Fulton (1956). This species has a somewhat slower pulse rate, around 5 pulses per second, but sings at a similar pitch, between 6.5 and 7 kHz (Walker and Funk, 2014) and has a similar pure tonal quality. The range and phenology of this species in North Carolina also closely overlaps that of Allonemobius tinnulus. Anaxipha tinnulenta, however, is associated with old fields, wood edges, and other fairly open, weedy habitats (Walker and Funk, 2014), not the dry woodlands occupied by A. tinnulus. Trigs also sing from up in vegetation whereas ground crickets stick close to the surface.
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.
Allonemobius tinnulus
Adult Dates:
 High Mountains (HM) ≥ 4,000 ft.
 Low Mountains (LM) < 4,000 ft.
 Piedmont (Pd)
 Coastal Plain (CP)

Click on graph to enlarge