**3. Results**

52 Zoology

Recording date

14/II/2000

22/II/2000

20/III/2001 23/III/2001

14/II/2000

22/II/2000

Observations of communicative and interactive behaviour and of the general activity of individuals were made in the laboratory and recorded with a JVC GR-AXM23 video-camera for subsequent analysis. Specimens were observed throughout the recordings, including

Sound recordings were analysed using a Mingograph 420 System attached to a digital oscilloscope (Tektronix 2211) and to a Krohn-Hite 3550 filter. To study the physical

Table 3. Summary of the information concerning specimens used to study the acoustic

mute periods, and the behaviour of the specimens in each situation was noted.

Recording conditions Tape

EL6/1999

EL3/2000

EL4/2000

EL3/2001

EL2/2000

EL3/2000

EL4/2000

Wood cage, (bulb 25W) 20ºC

Wood cage, (bulb 40W) 33ºC

Wood cage, (2 bulbs 40W) 31-32ºC

Glass cage (bulb 40W) 27-28 ºC

Wood cage, (bulb 40W) 33ºC

Wood cage, (bulb 40W) 32ºC

Wood cage, (2 bulbs 40W) 32 ºC

Type of sound and recording number

1 calling 4 courtship Rec.3/6/99

1 calling Rec. 2/3/2000 Rec.3/3/2000

4 calling 14 courtship Rec. 2/4/2000

96 disturbance 6 courtship Rec. 1/3/2002 Rec. 2/3/2001

36 disturbance 2 calling Rec. 8/2/2000

disturbance 10 calling 7 courtship Rec. 1/3/2000 Rec. 3/3/2000

1 courtship 12 disturbance Rec. 1/4/2000

118

Date and collector

1/IV/1999

13/II/2000 Clemente, García, Lorier

11/II/2000 Clemente, García, Lorier

18/III/2001 Lorier

12/II/2000 Clemente, García, Lorier

E.Lorier 18/IV/1999

Locality of

1 male

1 male

1 male

3 males

*R. pictus* 

*R. brunneri* 

3 males capture

Valle del Lunarejo. Rivera. Uruguay

Cerro Chato Dorado. Rivera. Uruguay

Rivera. Uruguay

Cerro Chato Dorado. Rivera. Uruguay

behaviour of *Rhammatocerus* and studied recordings.

Cerro Batoví. Tacuaremb. Uruguay

> The sounds recorded, emitted by males in different behavioral situations, were all produced by femoro-tegminal mechanism, rubbing the pegs of the stridulatory file of hind femora against some specialized tegminal veins.

> No differences between songs have been observed in relation to the recording conditions. No sound produced by females has been registered in any case, although they produce movements with their hind legs. These movements are of moderate amplitude, starting with the leg folded at about 45º respect the vertical and displacing about 45º from the starting position. This movement can be isolated, from resting position to the vertical, or be repeated several times, when close to other individuals, males or females.

The Acoustic Behaviour as a Tool for Biodiversity and Phylogenetic Studies: Case of

the *Rhammatocerus* Species Inhabiting Uruguay (Orthoptera, Acrididae, Gomphocerinae) 55

Fig. 1. Stridulatory files. A-D: *Rhammatocerus pictus*. A: male file general appearance, B: detail of male pegs of middle zone, C: female file general appearance, D: detail of female pegs of middle zone. E-H: *Rhammatocerus brunneri*. E: male file general appearance, F: detail of male pegs of middle zone, G: female file general appearance, H: detail of female pegs of

middle zone.
