01857nas a2200145 4500008004100000245015900041210006900200520126800269653003301537653002701570653002801597653001601625100002201641856004801663 1993 eng d00a‘Absolute steepness’ of ramps as an essential cue for auditory pattern recognition by a grasshopper (Orthoptera; Acrididae; Chorthippus biguttulus L.)0 aAbsolute steepness of ramps as an essential cue for auditory pat3 a

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.

10aAcoustic pattern recognition10aChorthippus biguttulus10aEnvelope of soundpulses10aGrasshopper1 avon Helversen, D. uhttp://link.springer.com/10.1007/BF0021368501911nas a2200193 4500008004100000022001400041245011100055210006900166260001600235520126000251653002701511653001601538653001801554653001601572653002501588100002601613700002301639856005501662 2018 eng d a0340-759400aThe impact of age and egg-laying cycle on female grasshoppers’ preference functions for acoustic signals0 aimpact of age and egglaying cycle on female grasshoppers prefere cJan-12-20183 a

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.

10aacoustic communication10aAge effects10aFemale choice10aOviposition10aPreference functions1 aAufderheide, Jennifer1 aRonacher, Bernhard uhttp://link.springer.com/10.1007/s00359-018-1307-802262nas a2200133 4500008004100000022001300041245007900054210006900133520179000202100002901992700002202021700001902043856006602062 2017 eng d a0022191000aBrain regions for sound processing and song release in a small grasshopper0 aBrain regions for sound processing and song release in a small g3 a

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.

1 aBhavsar, Mit, Balvantray1 aStumpner, Andreas1 aHeinrich, Ralf uhttp://linkinghub.elsevier.com/retrieve/pii/S002219101630242601955nas a2200109 4500008004100000245009200041210006900133520148400202100001701686700002201703856012001725 2014 eng d00aAsymmetrical integration of sensory information during mating decisions in grasshoppers0 aAsymmetrical integration of sensory information during mating de3 aDecision-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. 1 aClemens, Jan1 aKrämer, Stefanie uhttps://bio.acousti.ca/da/content/asymmetrical-integration-sensory-information-during-mating-decisions-grasshoppers00793nas a2200121 4500008004100000245010400041210006900145300001000214490000600224520029500230100001800525856012800543 1976 eng d00aA putative hybrid in nature between Chorthippus brunneus and C. biguttulus (Orthoptera : Acrididae)0 aputative hybrid in nature between Chorthippus brunneus and C big a71-740 v13 a

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.

1 aRagge, D., R. uhttps://bio.acousti.ca/da/content/putative-hybrid-nature-between-chorthippus-brunneus-and-c-biguttulus-orthoptera-acrididae01986nas a2200241 4500008004100000245013200041210006900173300001200242490000700254520119000261653001401451653001401465653001601479653001701495653001101512653001701523653001501540653000901555653001301564100001801577700002101595856012801616 1988 eng d00aThe songs and taxonomy of the grasshoppers of the Chorthippus biguttulus group in the Iberian Peninsula (Orthoptera: Acrididae)0 asongs and taxonomy of the grasshoppers of the Chorthippus bigutt a897-9290 v223 a

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.

10aacoustics10aAcrididae10aChorthippus10agrasshoppers10aIberia10aNorth Africa10aOrthoptera10asong10ataxonomy1 aRagge, D., R.1 aReynolds, W., J. uhttps://bio.acousti.ca/da/content/songs-and-taxonomy-grasshoppers-chorthippus-biguttulus-group-iberian-peninsula-orthoptera