Orthoptera of North Carolina

Family (Alpha):

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, GBIF	Technical 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 Alexander, 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 Alexander, 1957)	Forewing Length: 5.2-6.2 mm, males; 3.3-4.2 mm, females (Thomas and Alexander, 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 (Thomas and Alexander, 1957). Anaxipha exigua has a similar relationship between pitch and pulse rate -- see graph below. There may, however, be some consistent differences in the shape of the individual syllables. Those of melodius are strongly hook-shaped, as in other ground crickets, whereas the syllables of exigua are similar to those of other members of Anaxipha, forming a more symmetric, smooth arc or inverted v. Wherever possible, determining the location of the singer provides diagnostic information. Melodius, as a ground cricket, sings only on the ground, whereas exigua, a bush cricket, sings from up in the vegetation, although often fairly close to the ground.
Diagnostic Song Parameters:

Diagnostic Song Parameters:

Recording playback at normal speed.
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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) Click on graph to enlarge

Habitats and Life History

Habitats: The original populations in Ohio were associated with marsh edges (Thomas and Alexander, 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 Alexander (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.

See also Habitat Account for General Shoreline Forblands

Status in North Carolina

Natural Heritage Program Status: [W-PK]

Natural Heritage Program Ranks: GNR SNR [S2S3]

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

Comments: Relatively few 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 to Eunemobius carolinus, morphologically, and to Anaxipha exigua acoustically. 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: Steve Hall, Dee Stuckey, and Savannah Hall Orange Co. Comment:	Recorded by: Steve Hall Durham Co. Comment: 41 syllables per sec @ 7 khz and 82F
	Recorded by: Steve Hall Chatham Co. Comment:	Recorded by: Steve Hall Chatham Co. Comment: 38 syllables per second @ 6.8 kHz, upper song
	Recorded by: Steve Hall Chatham Co. Comment: 43 syllables per second @ 7.1 khz; 84 F (29 C). Brownwater river floodplain. Both frequency and amplitude are modulated.	Recorded by: Steve Hall Chatham Co. Comment: 35 syllables per second @ 7.4 kHz; river shoreline
	Recorded by: Steve Hall Chatham Co. Comment: 43 syllables per second @ 7.0 khz; 84 F.	Recorded by: Steve Hall Chatham Co. Comment: Intermittent trills; 36 syllables per sec. @ 7kHz and 84F
	Recorded by: Jim Petranka Burke Co. Comment: 29 syllables per second at 6.0 kHz; air temperature ca. 68F. Near a small seepage area on Shortoff Mountain. The shape of the syllables is unlike our other examples as is their somewhat paired arrangement.	Recorded by: Jim Petranka Richmond Co. Comment: 28 pulses per sec. @ 5.3 kHz; Air temp ca. 75F. Singing from near the margin of Lake Baggett.
	Recorded by: Steve Hall Durham Co. Comment: 30 pulses per second @ 5.8 kHz and 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 @ 5.8kHz and about 72F. 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.

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

Image Gallery for Eunemobius melodius - Melodious Ground Cricket

MP3 Gallery for Eunemobius melodius - Melodious Ground Cricket