Orthoptera of North Carolina
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View Gryllidae Members: NC Records

Eunemobius melodius (Thomas & Alexander, 1957) - Melodious Ground Cricket

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Taxonomy
Family: Gryllidae Subfamily: Nemobiinae Tribe: Pteronemobiini
Comments: One of three species in this genus that occur in North America north of Mexico (Cigliano et al., 2017), all of which have been recorded in North Carolina
Identification
Field Guide Descriptions: Online Photographs: OSF (specimen shots), Google Images,  iNaturalist, GBIFTechnical Description, Adults/Nymphs: Thomas and Alexander (1957)SINA 534a.htm                                                                                  
Comments: A small, dark ground cricket. Slightly larger but indistinguishable from E. carolinus in coloration and general structure (Thomas and Howard, 1957), including pale colored palps in both sexes (see specimens illustrated on OSF).
Total Length [body plus wings; excludes ovipositor]: 7.8-9.8 mm, males; 8.2-9.8 mm, females (Thomas and Howard, 1957)Forewing Length: 5.2-6.2 mm, males; 3.3-4.2 mm, females (Thomas and Howard, 1957)
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). Females can be distinguished from E. carolinus by their longer ovipostors, 4.7-5.4 mm in melodius vs. 2.6-3.1 mm in carolinus (Thomas and Alexander, 1957). Males can be distinguished by their larger number of stridulatory pegs -- 110-125 in melodius vs. 51-63 in carolinus. Thomas and Alexander also note that the pegs in carolinus do not reach the ulnar vein whereas they extend beyond it in melodius.
Singing Behavior: Songs consist of long trills composed of downslured pulses that give them a musical quality. This contrasts with those of E. carolinus, which are generally buzzy; melodius also lacks the frequency and pitch modulation and sometimes rhythmic cadence of carolinus. At temperatures between 65 and 80 F, the pulse rate ranges between 24-39 pulses per second and the dominant pitch between 4.8 to 6.1 kHz. Anaxipha exigua has a similar pulse rate but typically has a much higher dominant pitch, around 7.1 at 77 degrees F (= 25 C) (Walker and Funk, 2014).
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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)

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Habitats and Life History
Habitats: The original populations in Ohio were associated with marshes (Thomas and Howard, 1957). These included sites with relict, boreal species of plants, as well as areas grazed by livestock. Our records also come mainly from wet habitats, including pond and stream shorelines.
Diet: Probably omnivorous
Observation Methods: Most easily detected by its song. Thomas and Howard (1957) also report finding individuals by tearing apart a rotten, water-soaked log.
Abundance/Frequency: Thomas and Alexander (1957) report that colonies are highly restricted, not occupying the full extent of apparently suitable habitat
Adult Phenology: In most of its range, this adults emerge during the summer and persist until the fall. In Florida, however, some survive the winter and can be heard singing in March. We also have one such record but otherwise, we have too few records for this species to be sure of its phenology.
Status in North Carolina
Natural Heritage Program Status: [W3]
Natural Heritage Program Ranks: [GNR] S2S3
State Protection: Has no legal protection, although permits are required to collect it on state parks and other public lands
Comments: Only five populations have been recorded in North Carolina but at widely separated locations. The paucity of records is probably due to a lack of surveys but possibly also to confusion -- especially morphologically -- with Eunemobius carolinus. An accurate assessment of its conservation status requires more information about its distribution, habitat associations, populations trends, and threats.

Image Gallery for Eunemobius melodius - Melodious Ground Cricket

Recorded by: Jim Petranka
Burke Co.
Comment: 29 syllables per second; air temperature ca. 68F. Near a small seepage area on Shortoff Mountain.		 Recorded by: Jim Petranka
Richmond Co.
Comment: 28 pulses per sec.; Air temp ca. 75F. Singing from near the margin of Lake Baggett.
Recorded by: Steve Hall
Durham Co.
Comment: 30 pulses per second @ 70 F; faster and lower in pitch than other examples		 Recorded by: Ken Kneidel
Burke Co.
Comment: 28 pulses per second, 5.3 Hz, 64 F, along a woodland trail
Recorded by: Steve Hall and Bo Sullivan
Carteret Co.
Comment: Pulse rate = 36 pulses per second at about 72 degrees F.Recorded in an marshy area with Saccharum giganteum and Baccharis; located next to a tidal creek. No individuals were seen or collected.

MP3 Gallery for Eunemobius melodius - Melodious Ground Cricket

1 Recorded by: Jim Petranka
Burke Co.
2022-10-22
Near a small seepage area on Shortoff Mountain. Air temperature ca. 68 degrees. 		2 Recorded by: Jim Petranka
Richmond Co.
2022-03-18
Singing from near the margin of Lake Baggett. Air temp ca. 75F; 28 pulses per sec.