@article {58242, title = {{\textquoteleft}Absolute steepness{\textquoteright} of ramps as an essential cue for auditory pattern recognition by a grasshopper (Orthoptera; Acrididae; Chorthippus biguttulus L.)}, year = {1993}, abstract = {

Male grasshoppers of the species Chorthippus biguttulus react to female songs with a characteristic turn towards the female. The probability of turning towards female song models was used to evaluate those parameters which are essential for a signal to be interpreted as female song.

1.\ The shape of sound pulses turned out to be most decisive; pulses with ramps rising gradually over 3 and more ms were efficient (Figs. 2, 3), whereas rectangularly modulated pulses evoked only weak responses and only when pulse intervals were between 3 and 5 ms (Fig. 2). The decline of a pulse did not influence its efficiency (Fig. 3). In particular, pulses with sudden onsets and gradual declines were as weakly effective as rectangularly modulated ones and thus remarkably less effective than pulses with ramp-like onsets (Fig. 4).

2.\ Intensity tuning curves suggest, that the absolute steepness of ramps (expressed as \μbar/ms) is detected by the grasshopper nervous system (Figs. 6, 7), possibly by processing the delay in excitation onset of at least two receptor types differing in threshold sensitivity.

3.\ The sawtooth shape of pulses in female signals is suggested to be adaptive with respect to directional hearing.

}, keywords = {Acoustic pattern recognition, Chorthippus biguttulus, Envelope of soundpulses, Grasshopper}, doi = {10.1007/BF00213685}, url = {http://link.springer.com/10.1007/BF00213685}, author = {von Helversen, D.} } @article {53391, title = {The impact of age and egg-laying cycle on female grasshoppers{\textquoteright} preference functions for acoustic signals}, journal = {Journal of Comparative Physiology A}, year = {2018}, month = {Jan-12-2018}, abstract = {

Female responsiveness and the shape of preference functions for male signal traits are important determinants for male mating success. We observed the responsiveness and the selectivity of virgin grasshopper females (Chorthippus biguttulus L.) for different features of males\’ acoustic signals throughout their life span to detect possible influences of age on the females\’ preference functions. In particular, we explored the hypothesis that the females may become less selective with increasing age and, therefore, would start to accept songs that are normally rejected. Such an age effect could relieve the selection pressure on male signal traits. In the majority of animals tested, the general responsiveness decreased with age although a few individuals exhibited an opposite trend. Contrary to the above expectation, there was no indication of a loss of selectivity in older females or an increased acceptance of normally unattractive song models. The timing within the oviposition cycle had a strong effect on responsiveness: near oviposition the general responsiveness increased and with it also the half width of the preference functions. However, highly unattractive song models remained unattractive also near oviposition.

}, keywords = {acoustic communication, Age effects, Female choice, Oviposition, Preference functions}, issn = {0340-7594}, doi = {10.1007/s00359-018-1307-8}, url = {http://link.springer.com/10.1007/s00359-018-1307-8}, author = {Aufderheide, Jennifer and Bernhard Ronacher} } @article {17335, title = {Brain regions for sound processing and song release in a small grasshopper}, journal = {Journal of Insect Physiology}, year = {2017}, abstract = {

We investigated brain regions \– mostly neuropils - that process auditory information relevant for the initiation of response songs of female grasshoppers Chorthippus biguttulus during bidirectional intraspecific acoustic communication. Male-female acoustic duets in the species Ch. biguttulus require the perception of sounds, their recognition as a species- and gender-specific signal and the initiation of commands that activate thoracic pattern generating circuits to drive the sound-producing stridulatory movements of the hind legs. To study sensory-to-motor processing during acoustic communication we used multielectrodes that allowed simultaneous recordings of acoustically stimulated electrical activity from several ascending auditory interneurons and local brain neurons and subsequent electrical stimulation of the recording site. Auditory activity was detected in the lateral protocerebrum (where most of the described ascending auditory interneurons terminate), in the superior medial protocerebrum and in the central complex, that has previously been implicated in the control of sound production. Neural responses to behaviorally attractive sound stimuli showed no or only poor correlation with behavioral responses. Current injections into the lateral protocerebrum, the central complex and the deuto-/tritocerebrum (close to the cerebro-cervical fascicles), but not into the superior medial protocerebrum, elicited species-typical stridulation with high success rate. Latencies and numbers of phrases produced by electrical stimulation were different between these brain regions. Our results indicate three brain regions (likely neuropils) where auditory activity can be detected with two of these regions being potentially involved in song initiation.

}, issn = {00221910}, doi = {10.1016/j.jinsphys.2017.03.006}, url = {http://linkinghub.elsevier.com/retrieve/pii/S0022191016302426}, author = {Mit Balvantray Bhavsar and Stumpner, Andreas and Heinrich, Ralf} } @article {11295, title = {Asymmetrical integration of sensory information during mating decisions in grasshoppers}, journal = {Proceedings of the National Academy of Sciences}, year = {2014}, abstract = {Decision-making processes, like all traits of an organism, are shaped by evolution; they thus carry a signature of the selection pressures associated with choice behaviors. The way sexual communication signals are integrated during courtship likely reflects the costs and benefits associated with mate choice. Here, we study the evaluation of male song by females during acoustic courtship in grasshoppers. Using playback experiments and computational modeling we find that information of different valence (attractive vs. nonattractive) is weighted asymmetrically: while information associated with nonattractive features has large weight, attractive features add little to the decision to mate. Accordingly, nonattractive features effectively veto female responses. Because attractive features have so little weight, the model suggests that female responses are frequently driven by integration noise. Asymmetrical weighting of negative and positive information may reflect the fitness costs associated with mating with a nonattractive over an attractive singer, which are also highly asymmetrical. In addition, nonattractive cues tend to be more salient and therefore more reliable. Hence, information provided by them should be weighted more heavily. Our findings suggest that characterizing the integration of sensory information during a natural behavior has the potential to provide valuable insights into the selective pressures shaping decision-making during evolution. }, doi = {10.1073/pnas.1412741111}, author = {Jan Clemens and Stefanie Kr{\"a}mer} } @article {11153, title = {A putative hybrid in nature between Chorthippus brunneus and C. biguttulus (Orthoptera : Acrididae)}, journal = {Systematic Entomology}, volume = {1}, year = {1976}, pages = {71-74}, chapter = {71}, abstract = {

The characteristics of the song and morphology of a probable natural hybrid between the two grass- hoppers Chorthippus brunneus (Thunberg) and C. bigurruius (L.) are described and compared with those of the parent species. The status of C. eisentrauti (Ramme) is briefly discussed.

}, doi = {10.1111/j.1365-3113.1976.tb00033.x}, author = {D. R. Ragge} } @article {11152, title = {The songs and taxonomy of the grasshoppers of the Chorthippus biguttulus group in the Iberian Peninsula (Orthoptera: Acrididae)}, journal = {Journal of Natural History}, volume = {22}, year = {1988}, pages = {897-929}, chapter = {897}, abstract = {

The Chorthippus biguttulus group includes a number of common European species that are difficult to distinguish morphologically but are easily recognized in the field by the distinctive calling songs of the males. These song-patterns have not previously been studied in Spain and as a result the Iberian members of the group have been misidentified in almost all the extensive Spanish literature on the ecology and cytogenetics of these insects. In this study the male calling songs of all six members of the group known from the Iberian Peninsula and North Africa are fully described and illustrated with oscillograms at several different speeds. The songs of the three species known only from Iberia or North Africa, jacobsi, yersini and marocanus, are fully described for the first time (marocanus is here raised in rank from subspecies). Notes on recognition, using both morphology and song, are given for each species, and two identification keys are provided, one based on morphology and the other on song. It is shown that the three species biguttulus, brunneus and mollis, previously believed to be widespread in Iberia, are absent from most of the peninsula.

}, keywords = {acoustics, Acrididae, Chorthippus, grasshoppers, Iberia, North Africa, Orthoptera, song, taxonomy}, doi = {10.1080/00222938800770611}, author = {D. R. Ragge and W. J. Reynolds} }