Orthoptera of North Carolina
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View Gryllidae Members: NC Records

Eunemobius confusus (Blatchley, 1903) - Confused Ground Cricket


Family: Gryllidae Subfamily: Nemobiinae Tribe: PteronemobiiniSynonym: Nemobius confusus
Comments: One of three species in this genus that occur in North America north of Mexico (Cigliano et al., 2017), all three of which have been recorded in North Carolina
Field Guide Descriptions: Elliot and Hershberger (2006)Online Photographs: SINA, Songs of Insects, Google Images, GBIFTechnical Description, Adults/Nymphs: Hebard (1913)SINA 538a.htm                                                                                  
Comments: A glossy, pitch black ground cricket. The head, thorax, and tegmina are shiny blackish-brown, with the legs somewhat lighter brown. The bone-white palps of both sexes are highly characteristic (Hebard, 1913). Eunemobius carolinus also has pale, but not bone-white palps, and can also be distinguished from confusus by the much lighter, yellowish-brown color of its head and thorax.
Total Length [body plus wings; excludes ovipositor]: 6.4, males; 6.7, females (Hebard, 1913)
Structural Features: Members of Eunemobius can be distinguished from Allonemobius and Neonemobius by their possession of equal length ventral spurs on the hind tibiae and by ovipositors that have serrulations on the ventral margin of the tip (smooth in the other genera) and coarse teeth on the dorsal margin (finely serrulate in the other genera) (Hebard, 1913; SINA, 2017). Hebard (1913) stated that the hindwings are absent in this species. Fulton (1931) also did not include confusus in the group of species with macropterous forms.
Singing Behavior: Fulton (1931) described the song of confusus as a "droning, buzzy trill like the song of carolinus", but with a consistent division into two (sometimes three) weak pulses, followed by a longer one that rises in volume followed by pause. Each of these trills are given at a rate of one to two per second at 70 F. A song presented on SINA has a dominant pitch of 6.9 kHz.
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: In his description of the species, Blatchely (1903) mentioned that it was common in "low damp woods bordering Tippicanoe Lake". (Brimley (1908) also described the habitat of confusus as "damp places, not far from water". On the other hand, Fulton (1931) described it as less of a bottomland and mesic forest species than Allonemobius maculatus, and that it appeared, instead, to prefer hardwood forests growing on well-drained slopes and uplands.
Diet: Probably omnivorous
Observation Methods: Most easily detected by its song.
Abundance/Frequency: Fulton (1931) described this species as "never very abundant"
Adult Phenology: Fulton (1931) noted that adults of confusus have been found near Raleigh as early as July 29. Brimley (1908) reported finding it in the same area from mid-August to late November.
See also Habitat Account for General Mesic Hardwood Forests
Status in North Carolina
Natural Heritage Program Status:
Natural Heritage Program Ranks: [GNR] S3S5
State Protection: Has no legal protection, although permits are required to collect it on state parks and other public lands
Comments: We currently have too few records for this species to be sure of its status in North Carolina. While it seems likely to occur in hardwood forests across at least the Piedmont and low mountains, if it is actually a flightless species, the effects of habitat fragmentation need to be determined.

Image Gallery for Eunemobius confusus - Confused Ground Cricket

Recorded by: Jim Petranka
Clay Co.
Recorded by: Stephen Hall
Orange Co.
Recorded by: Jim Petranka Petranka and Becky Elkin
Graham Co.
Recorded by: Jim Petranka
Madison Co.
Recorded by: Steve Hall
Orange Co.
Recorded by: Stephen Hall
Orange Co.
Recorded by: Steve Hall
Orange Co.
Comment: Singing from under ornamental Rhododendrons. 21:50, ~74 F.

MP3 Gallery for Eunemobius confusus - Confused Ground Cricket

1 Recorded by: Jim Petranka
Clay Co.
Individuals were calling from a roadbank with Rhododendrons at the top.
2 Recorded by: Jim Petranka Petranka and Becky Elkin
Graham Co.
In a somewhat mesic hardwood forest with Liriodendron, Acer rubrum, Oxydendron, and Betula lenta.
3 Recorded by: Jim Petranka
Madison Co.
Singing from the base of a native azalea; air temperature ~ 76F.