Amblycorypha zipticka Forrest & Hamel, 2025

Forrest, Timothy G., Hamel, Jennifer A. & Holbrook, C. Tate, 2025, Calling songs and duets of two new species in the Amblycorypha rotundifolia complex (Tettigoniidae, Phaneropterinae), Journal of Orthoptera Research 34 (2), pp. 233-248 : 233-248

Amblycorypha zipticka Forrest & Hamel sp. nov.

Figs 1 , 3 , 4 , 5 , 7 , 6 , 12 , 13 ; Table 1

Material examined. —

Holotype: USA • ♂; North Carolina, Madison Co, Rich Mountain ; 35.9271°N, 82.8063°W; 10 Sep. 2006; T. G. Forrest leg.; Au 2 Rich-M 02-2006 ; DNA (MS-077); REC (2006 Tape 01 PGM 32); UNCA to be transferred to FSCA . Allotype: USA • ♀; North Carolina, Madison Co, Rich Mountain ; 35.9271°N, 82.8063°W; 10 Sep. 2006; T. G. Forrest leg.; Au 2 Rich-F 01-2006 ; DNA (MS-080); UNCA to be transferred to FSCA . Paratypes: (27 ♂, 10 ♀) USA • 1 ♂; North Carolina, Madison Co, Rich Mountain ; 35.9271°N, 82.8063°W; 3 Aug. 2002; T. K. Goodman leg.; UNCA to be transferred to FSCA • 2 ♀, 2 ♂; North Carolina, Madison Co, Rich Mountain ; 35.9271°N, 82.8063°W; 14 Aug. 2003; T. G. Forrest and T. K. Goodman leg.; UNCA to be transferred to FSCA • 7 ♀, 6 ♂; North Carolina, Madison Co, Rich Mountain ; 35.9271°N, 82.8063°W; 28 Jun. 2004; T. G. Forrest and J. A. Hamel leg.; UNCA to be transferred to FSCA • 8 ♂; North Carolina, Madison Co, Rich Mountain ; 35.9269°N, 82.8061°W; 26 Aug. 2004; J. A. Hamel and C. T. Holbrook leg.; UNCA to be transferred to FSCA • 7 ♂; North Carolina, Madison Co, Rich Mountain ; 35.9269°N, 82.8061°W; 1 Oct. 2004; T. G. Forrest, J. A. Hamel and C. T. Holbrook leg.; UNCA to be transferred to FSCA • 2 ♂; North Carolina, Madison Co, Rich Mountain ; 35.9271°N, 82.8063°W; 10 Sep. 2006; T. G. Forrest leg.; UNCA to be transferred to FSCA • 1 ♀, 1 ♂; North Carolina, Madison Co, Rich Mountain ; 35.9271°N, 82.8063°W; 7 Jul. 2011; T. G. Forrest leg.; UNCA to be transferred to FSCA .

Size measurements (mm). —

Holotype: PrnL: 5.2, PrnW: 4.0, TegL: 24.8, TegW: 7.6, HwEx: 3.2, FemL: 23.9, and TibL: 25.8. Allotype: PrnL: 5.7, PrnW: 3.8, TegL: NA, TegW: 7.0, HwEx: NA, FemL: 23.3, TibL: 24.0, OviL: 8.6 (Fig. 1 ).

Etymology. —

This species is named for its multi-component calling song that includes zips and ticks, which are not found in other members of the group.

Common name. —

Zip Ticker Round-winged Katydid.

Differential diagnosis. —

The best way to distinguish A. zipticka from other members of the rotundifolia complex is by male calling song. The songs are multi-component and include clicks, zips, and ticks. Clicks have one or two brief impulse trains followed by a longer terminal train of impulses. Clicks temporally resemble song elements of other members of the group, but the relationships of click rate with temperature differ among all members of the complex east of the Mississippi River. Click rates of A. zipticka are 1.5 / s at 25 ° C compared to 3.3 / s for A. alexanderi , 10.0 / s for A. bartrami , 5.8 / s for A. carolina Spooner and Forrest 2023 , 11.6 / s for A. peedee Forrest 2023 , and 13.0 / s by male A. tallapoosa Forrest 2023 ( Walker et al. 2003, Forrest et al. 2023). A. zipticka also produces two other sound elements while calling: zips and ticks. No other members of the rotundifolia complex produce zips, each a train of impulses caused by the impacts of the plectrum on a single tooth of the file. Locale might also be used to distinguish this species because it is only known from a single local population in Madison County, NC. However, we expect other undiscovered demes to occur in western North Carolina. Additionally, size could help distinguish A. zipticka from all other described members of the group because the mean measures of nearly all morphological characters are smaller than those of all other members of the rotundifolia complex.

This species is known only from a single locality in Madison County, NC, despite extensive surveys in the area. The population was discovered by Tamara Goodman while surveying for populations of Scudderia septentrionalis ( Serville, 1838) . Interestingly, the calling song of S. septentrionalis contains similar acoustic elements (rasps and ticks; see Forrest and Goodman 2008) to the calling song of A. zipticka .

Description. —

Individuals are typically green and exhibit characteristics of the rotundifolia complex (lateral lobe of pronotum with shallow humeral sinus and metasternal lobe wider than long; Walker et al. 2003). Morphological measurements (x ̄ ± SE in mm, N) of females average PrnL: 5.6 ± 0.05, 11; PrnW: 3.9 ± 0.06, 11; TegL: 22.4 ± 0.31, 10; TegW: 6.6 ± 0.14, 11; FemL: 23.0 ± 0.24, 11; TibL: 24.2 ± 0.20, 11; OviL: 8.31 ± 0.08, 11. Male size measurements average PrnL: 5.0 ± 0.04, 28; PrnW: 3.8 ± 0.03, 28; TegL: 22.9 ± 0.18, 28; TegW: 7.2 ± 0.07, 28; FemL: 22.7 ± 0.17, 28; TibL: 24.5 ± 0.20, 28 (Table 1 ).

Male calling songs are composed of three acoustic elements: clicks, zips, and ticks. Clicks have 1–2 short impulse trains followed by a longer terminal train. Zips are each a single train of impulses. Click rate and zip rate change with temperature in linear relationships: click rate = 0.059 T- 0.010 and zip rate = 0.150 T + 0.052. Click rates are slower than zip rates (1.5 / s vs 3.8 / s at 25 ° C). The typical sequence of song elements during calling is a series of slow clicks that transition to a fast series of zips followed by multiple ticks.

Figures

Fig. 1. Holotype (A. Dorsal view, B. Lateral view) and allotype (C. Dorsal view, D. Lateral view) of Amblycorypha zipticka, the Zip Ticker Round-winged Katydid. Scale bars: 5 mm.

Fig. 3. Oscillograms (25 s) of the calling songs of 4 male A. zipticka showing the general temporal structure of calling. Songs consist of two syllable types, clicks and zips. Above portions of each oscillogram, colored bars indicate clicks (blue), zips (red), and ticks (green). Clicks are emitted at slower rates and transition to a faster series of zips that are then followed by a series of brief impulses (ticks). Scale bar: 5 s.

Fig. 4. A, E. Oscillograms (12.5 s) of calling songs of 2 male A. zipticka. Scale bar: 1 s. Three different sound elements of the song are highlighted (blue: clicks, red: zips, and green: zip (s) followed by ticks and then a click); B, F. Oscillogram and spectrogram of clicks highlighted by blue in A and E, respectively; C, G. Oscillogram and spectrogram of zips outlined by red in A and E; D, H. Sections of A and E outlined in green showing the transition between last zip to a series of ticks followed by a click.

Fig. 5. Fine temporal structure of a click (left) and a zip (right) from the same recording of 4 male A. zipticka. Scale bar: 100 ms.

Fig. 6. Mean (± SE) syllable rates as a function of temperature during calling by male A. zipticka for clicks (blue fit: rate = 0.059 T- 0.010) and zips (red fit: rate = 0.150 T + 0.052). Numbers beside each mean represent the individual (n = 17) whose mean rate was measured. Individuals whose click rate and zip rate were calculated at the same temperature are from the same recording. The dotted line is the same function for clicks of A. alexanderi from Walker et al. 2003.

Fig. 7. Oscillograms showing the fine temporal structure of echemes produced by 4 male A. monticola. The smaller amplitude sounds between each impulse train are from the opening stroke of the tegmina. Opening (O) and closing (C) strokes are indicated for the top oscillogram. Scale bar: 100 ms.

Fig. 12. Oscillograms of portions of duets between 3 A. zipticka pairs (female upper trace, male lower trace). The final zip of each male’s song is highlighted in red, subsequent clicks are highlighted in blue, and the intervening ticks of the male are highlighted in green. Female tick replies are highlighted in purple. Lower amplitude male songs (grey) are seen in the female traces. Scale bar: 500 ms.

Fig. 13. Distributions of male (green) and female (purple) ticks in A. zipticka as a function of the proportion of time between the zip and click (0.0–1.0) and between the first click and next click (1.0–2.0). A. Schematic of the final portion of the calling song sequence with 3 song components, zip (red), clicks (blue), and ticks (green). B. Overall distribution of male ticks in the song (green) including the mean ± SE (green circles) of individual ticks in the sequences (1–10) between the zip and click. C. Same as in B but measured during duets with females. D. Distribution of female tick responses during the duets in C.