Calling Song Research Articles

A New North American Species ofBucrates(Orthoptera: Tettigoniidae: Conocephalinae: Copiphorini)

Bucrates weissmani n.sp. is known from four localities in southern Arizona. It is smaller and more slender than the other four species of Bucrates, making it superficially similar to the Central American copiphorine Caulopsis cuspidata, but more fundamental features refute the notion that it belongs in Caulopsis rather than Bucrates. Four other species of Bucrates are known. Two of these, capitatus (De Geer) and clausus (Scudder), occur in sympatry in Central America and tropical South America; lanista Rehn is known only from southern Brazil; and malivolans (Scudder) is restricted to the southeastern United States. All are easily distinguished morphologically and, for the three for which the songs are known, by their songs. Unlike the two other species of Bucrates for which the habitat is known, B. weissmani occurs on altitudinal islands at the edge of a desert. The calling song of B. weissmani resembles that of numerous species of Neoconocephalus, whereas the songs of B. malivolans and B. capitatus, resemble each other more than either song resembles that of B. weissmani.

The secret stridulatory file under the right tegmen in katydids (Orthoptera, Ensifera, Tettigonioidea).

Males of most species of crickets and katydids produce species-specific calling songs to attract conspecific females. The typical stridulatory apparatus of the Ensifera consists of a file-and-scraper system in the basal dorsal region of the forewings (tegmina): the file on the underside of the cubital vein of one tegmen is composed of a series of lamelliform teeth and is run against the sclerotized scraper at the edge of the other tegmen. The region directly distal of the cubital vein is often thin and glassy and serves to amplify and spread the sound. In stridulating crickets the tegmina are quite symmetrical with both the left and the right one containing a file, which is considered the ancestral condition (Béthoux 2012). Most of these crickets adopted a right-over-left wing overlap and use only the right file. The few extant species of the ancient group Hagloidea have bilaterally symmetrical tegmina, both with functional files, and individual males can change the overlap (Morris & Gwynne 1978). Katydids are distinguished by a left-over-right wing overlap, with a stridulatory file on the underside of the left tegmen, and a scraper on the right one, which usually is also equipped with a mirror as resonating structure.

Shrinking wings for ultrasonic pitch production: hyperintense ultra-short-wavelength calls in a new genus of neotropical katydids (Orthoptera: Tettigoniidae).

This article reports the discovery of a new genus and three species of predaceous katydid (Insecta: Orthoptera) from Colombia and Ecuador in which males produce the highest frequency ultrasonic calling songs so far recorded from an arthropod. Male katydids sing by rubbing their wings together to attract distant females. Their song frequencies usually range from audio (5 kHz) to low ultrasonic (30 kHz). However, males of Supersonus spp. call females at 115 kHz, 125 kHz, and 150 kHz. Exceeding the human hearing range (50 Hz–20 kHz) by an order of magnitude, these insects also emit their ultrasound at unusually elevated sound pressure levels (SPL). In all three species these calls exceed 110 dB SPL rms re 20 µPa (at 15 cm). Males of Supersonus spp. have unusually reduced forewings (<0.5 mm2). Only the right wing radiates appreciable sound, the left bears the file and does not show a particular resonance. In contrast to most katydids, males of Supersonus spp. position and move their wings during sound production so that the concave aspect of the right wing, underlain by the insect dorsum, forms a contained cavity with sharp resonance. The observed high SPL at extreme carrier frequencies can be explained by wing anatomy, a resonant cavity with a membrane, and cuticle deformation.

Taxonomic, bioacoustic and faunistic data on a collection of Tettigonioidea from Eastern Congo (Insecta: Orthoptera).

During a 14-day excursion in March 1990, 28 species of tettigonioids were found at Irangi (1º54'S, 28º27'E), ca.100 km north west of Bukavu at Lake Kivu (Democratic Republic of the Congo, formerly Zaire), and at other localities near Bukavu. One species -Arantia (Arantia) gracilicercata Heller sp. n. - is new to science, another one-Pantecphyllus helleri Schmidt et al. 2004-was already described as new in a generic revision. All our specimens of the morphologically quite diverse and sexually dimorphic phaneropterine genus Arantia were studied using molecular methods. We propose a new subgenus Arantia (Euarantia) Heller subgen. n. based on relative tegmen width. Songs and stridulatory organs were studied in 9 species. Two phaneropterines, Horatosphaga leggei and Pardalota asymmetrica, showed remarkable calling songs lasting more than 10 s and produced by quite complicated stridulatory movements. The song of the large phaneropterine Zeuneria biramosa is noteworthy because of its unusually low carrier frequency of 3.7 kHz. Based on the examination of other specimens and species, some taxonomic changes are proposed (Phaneropteridae Burmeister, 1838 stat. rev.; Afromecopoda monroviana (Karsch, 1886) stat. rev.; Leproscirtus ebneri Karny, 1919, syn. n., Leproscirtus karschi Karny, 1919, syn. n., Leproscirtus granulosus aptera Karny, 1919, syn. n., all synonyms of Leproscirtus granulosus (Karsch, 1886); Lanistoides Sjöstedt, 1913 stat. rev.; Plastocorypha cabrai Griffini, 1909 stat. n.).

Solutions to cocktail-party-like problems in acoustic insects

Insects often communicate by sound in mixed species choruses; like humans and many vertebrates, in crowded social environments, they thus have to solve cocktail-party-like problems in order to ensure successful communication. This is a particular problem in species-rich environments like tropical rainforests with background noise levels of up to 60 dB SPL. I describe three “bottom-up” mechanisms in cricket receivers, which contribute to an excellent neuronal representation of conspecific signals under such conditions. First, more sharply tuned frequency selectivity of the receiver reduces the amount of masking energy around the species-specific calling song frequency, resulting in a signal-to-noise ratio (SNR) of −8 dB, when masker and signal were broadcast from the same side. Second, spatial release from masking improved the SNR by further 6 to 9 dB. Neurophysiological experiments carried out in the nocturnal rainforest yielded a further improvement of SNRs by 8 dB compared to the laboratory. Finally, a neuronal gain control mechanism enhances the contrast between the responses to signals and the masker, by inhibition of neuronal activity in inter-stimulus intervals. The results indicate that without knowledge of receiver properties and the spatial release mechanisms the detrimental effect of noise may be strongly overestimated.

Fiddler on the tree--a bush-cricket species with unusual stridulatory organs and song.

Insects of the order Orthoptera are well-known for their acoustic communication. The structures used for this purpose show a high diversity which obviously relates to differences in song parameters and to the physics of sound production. Here we describe song and morphology of the sound producing organs of a tropical bush-cricket, Ectomoptera nepicauda, from East Africa. It has a very unusual calling song consisting of frequency-modulated, pure-tone sounds in the high ultrasonic range of 80 to120 kHz and produced by extremely fast wing movements. Concerning morphology, it represents the most extreme state in the degree of left-right fore-wing differentiation found among Orthoptera: the acoustic parts of the left fore-wing consist exclusively of the stridulatory file, comparable in function to the bow of a violin, while the right wing carries only the plectrum ( = string) and mirror ( = soundbox).

&lt;p&gt;&lt;strong&gt;&lt;em&gt;Zebragryllus&lt;/em&gt; Desutter-Grandcolas &amp;amp; Cadena-Casteñada, n.gen. a new Gryllinae genus from Eastern and Western Amazonia, South America (Orthoptera, Grylloidea, Gryllidae)&lt;/strong&gt;&lt;/p&gt;

We describe a new genus of grylline cricket, Zebragryllus Desutter-Grandcolas & Cadena-Casteñada n. gen., from the Neotropical Region, using characters of morphology and male genitalia; genitalic characters clearly show that Zebragryllus n. gen. is closely related to Anurogryllus Saussure, 1878. Six species are described as new to science, origina<a href="http://dx.doi.org/10.1046/j.1463-6409.2003.00142.x">t</a>ing from western (Peru, Colombia) and eastern (French Guiana) Amazonia: Zebragryllus fuscus Desutter-Grandcolas, n. sp., Z. guianensis Desutter-Grandcolas, n. sp., Z. intermedius Desutter-Grandcolas, n. sp., Zebragryllus nauta Desutter-Grandcolas, n. sp., Zebragryllus nouragui Desutter-Grandcolas, n. sp., and Zebragryllus wittoto Desutter-Grandcolas and Cadena-Casteñada, n. sp., type species of the genus. They are characterized by their size, coloration (shining black, most often with white patterns of coloration, hence the genus name), and male and female genitalia. The calling songs of Z. guianensis Desutter-Grandcolas, n. sp., Z. intermedius Desutter-Grandcolas, n. sp., Z. nouragui Desutter-Grandcolas, n. sp., and Z. wittoto Desutter-Grandcolas and Cadena-Casteñada, n. sp. are described. An identification key is proposed for both males and females.

Auditory pattern recognition and steering in the cricket Teleogryllus oceanicus

AbstractMale crickets Teleogryllus oceanicus (Le Guillou) produce a complex species‐specific calling song with phrases combining groups of single pulses (chirps) and groups of double‐pulses (trills) to attract females, which fly or walk towards singing males. In open‐loop trackball experiments, phonotactic steering responses to normal calling song phrases consisting of chirps and trills are strongest, suggesting that both components are necessary for maximal attractiveness. Sequences of just chirps or trills are less effective in eliciting phonotactic walking and steering. Split‐song paradigms are used to analyze the steering behaviour underlying orientation in more detail. The females' phonotactic steering reflects the alternating acoustic pattern of the split‐song paradigm. Analysis with high temporal resolution demonstrate, that even when the calling song is presented only from one side, the steering velocity and lateral deviation towards the song is modulated by steering events to single‐sound pulses. Therefore, pattern recognition, which integrates the structure of the song, appears not to be directly involved in the rapid steering response. This organization of phonotactic behaviour with a parallel processing of pattern recognition and steering is similar to other cricket species and may allow T. oceanicus females to steer transiently towards distorted song patterns as they occur in natural habitats.

A new species of Cardiodactylus (Orthoptera: Grylloidea: Eneopterinae)from Singapore.

Cardiodactylus is a speciose cricket genus belonging to the subfamily Eneopterinae. One new species of Cardiodactylus from Singapore is described: Cardiodactylus admirabilis Tan & Robillard n. sp. Acoustic analysis is also performed on the male calling song. A key to species of Eneopterinae from Singapore is provided.

A Modified Mole Cricket Lure and Description ofScapteriscus borellii(Orthoptera: Gryllotalpidae) Range Expansion and Calling Song in California

Invasive mole cricket species in the genus Scapteriscus have become significant agricultural pests and are continuing to expand their range in North America. Though largely subterranean, adults of some species, such as Scapteriscus borellii Giglio-Tos 1894, are capable of long dispersive flights and phonotaxis to male calling songs to find suitable habitats and mates. Mole crickets in the genus Scapteriscus are known to be attracted to and can be caught by audio lure traps that broadcast synthesized or recorded calling songs. We report improvements in the design and production of electronic controllers for the automation of semipermanent mole cricket trap lures as well as highly portable audio trap collection designs. Using these improved audio lure traps, we collected the first reported individuals of the pest mole cricket S. borellii in California. We describe several characteristic features of the calling song of the California population including that the pulse rate is a function of soil temperature, similar to Florida populations of S. borellii. Further, we show that other calling song characteristics (carrier frequency, intensity, and pulse rate) are significantly different between the populations.

Lack of correlation between vertical distribution and carrier frequency, and preference for open spaces in arboreal katydids that use extreme ultrasound, in Gorgona, Colombia (Orthoptera: Tettigoniidae)

Male Tettigoniidae emit sound to attract conspecific females. The sound is produced by stridulation. During stridulation the forewings open and close, but it is during the closing stroke that the scraper contacts the file teeth to generate the predominant sound components, which are amplified by adjacent wing cells specialized in sound radiation. The sounds usually exceed the sonic boundary and might occur above 40 kHz, reaching extreme ultrasonic frequencies of 150kHz in some species. Here we test the hypothesis that Tettigoniidae species should prefer microhabitats that favour efficient signal transmission, i.e. that there is a relationship of sound frequency with the vertical distribution of the species (from ground to canopy) at Gorgona National Natural Park, Colombia. We sampled 16 trees and four different altitudinal levels between 1 and 20m above the understory vegetation. We placed collecting blankets separated by vertical distances of 5m, and knocked insects down using the technique known as fogging. We found no correlation between vertical distribution and carrier frequency, but there was a preference for open spaces (below the canopy and above the understory) in species using extreme ultrasound. This is the first quantitative description of the vertical distribution in neotropical species of the family Tettigoniidae and its relationship to the calling song frequency. Rev. Biol. Trop. 62 (Suppl. 1): 289-296. Epub 2014 February 01.

Useless hearing in male Emblemasoma auditrix (Diptera, Sarcophagidae)--a case of intralocus sexual conflict during evolution of a complex sense organ?

Sensory modalities typically are important for both sexes, although sex-specific functional adaptations may occur frequently. This is true for hearing as well. Consequently, distinct behavioural functions were identified for the different insect hearing systems. Here we describe a first case, where a trait of an evolutionary novelty and a highly specialized hearing organ is adaptive in only one sex. The main function of hearing of the parasitoid fly Emblemasoma auditrix is to locate the host, males of the cicada species Okanagana rimosa, by their calling song. This task is performed by female flies, which deposit larvae into the host. We show that male E. auditrix possess a hearing sense as well. The morphology of the tympanal organ of male E. auditrix is rather similar to the female ear, which is 8% broader than the male ear. In both sexes the physiological hearing threshold is tuned to 5 kHz. Behavioural tests show that males are able to orient towards the host calling song, although phonotaxis often is incomplete. However, despite extensive observations in the field and substantial knowledge of the biology of E. auditrix, no potentially adaptive function of the male auditory sense has been identified. This unique hearing system might represent an intralocus sexual conflict, as the complex sense organ and the behavioural relevant neuronal network is adaptive for only one sex. The correlated evolution of the sense organ in both sexes might impose substantial constraints on the sensory properties of the ear. Similar constraints, although hidden, might also apply to other sensory systems in which behavioural functions differ between sexes.

Supplementary data for: A Modified Mole Cricket Lure and Description of Scapteriscus borellii (Orthoptera: Gryllotalpidae) Range Expansion and Calling Song in California

Supplementary data for: A Modified Mole Cricket Lure and Description of Scapteriscus borellii (Orthoptera: Gryllotalpidae) Range Expansion and Calling Song in California

Phase shifts in binaural stimuli provide directional cues for sound localisation in the field cricket Gryllus bimaculatus.

The cricket's auditory system is a highly directional pressure difference receiver whose function is hypothesised to depend on phase relationships between the sound waves propagating through the auditory trachea that connects the left and right hearing organs. We tested this hypothesis by measuring the effect of experimentally constructed phase shifts in acoustic stimuli on phonotactic behavior of Gryllus bimaculatus, the oscillatory response patterns of the tympanic membrane, and the activity of the auditory afferents. The same artificial calling song was played simultaneously at the left and right sides of the cricket, but one sound pattern was shifted in phase by 90 deg (carrier frequencies between 3.6 and 5.4 kHz). All three levels of auditory processing are sensitive to experimentally induced acoustic phase shifts, and the response characteristics are dependent on the carrier frequency of the sound stimulus. At lower frequencies, crickets steered away from the sound leading in phase, while tympanic membrane vibrations and auditory afferent responses were smaller when the ipsilateral sound was leading. In contrast, opposite responses were observed at higher frequencies in all three levels of auditory processing. Minimal responses occurred near the carrier frequency of the cricket's calling song, suggesting a stability at this frequency. Our results indicate that crickets may use directional cues arising from phase shifts in acoustic signals for sound localisation, and that the response properties of pressure difference receivers may be analysed with phase-shifted sound stimuli to further our understanding of how insect auditory systems are adapted for directional processing.

The morphological and behavioral analysis of geographically separated Rammeihippus turcicus (Orthoptera: Acrididae: Gomphocerinae) populations: data result in taxonomical conflict.

Rammeihippus Woznessenskij, 1996 (Orthoptera: Acrididae: Gomphocerinae) is a genus represented by two species. Rammeihippus turcicus (Ramme, 1939) is the only known species of the genus from Anatolia. As for most of the Gomphocerinae species in Anatolia, all populations of the species are intermittently distributed at high altitudes. In this study, three populations of R. turcicus were studied for the first time to determine the song and mating behavior. Males of the species produce typical calling song for Gomphocerinae and complex courtship songs and mating behavior. Thus, an accurate taxonomy requires extensive material and different character sources. In this study, the Anatolian Rammeihippus was re-examined on the basis of qualitative and morphometric morphology, male songs, and behavioral characteristics. There was no agreement between the results of the song and morphology. Acoustic analysis suggested one species and patchy distribution in the area, whereas morphology pointed out that each population was a different taxonomical unit. The results of the study show that the aberrant morphology does not necessarily indicate a new species in the Gomphocerinae genus.

都市近郊の農村域におけるクツワムシの生息実態

The calling songs of cicadas and orthopterans have had a symbolic influence on the Japanese people, and these species are important as they make people understand the value of ecosystem services. In this study, we focused on Mecopoda nipponensis, a well-known acoustic insect in Japan, and we aimed to clarify its distribution in rural areas near large cities. The study site was Ushiku and Tsukuba Cities in Ibaraki Prefecture, Japan. By using a method for counting the sound of M. nipponensis, we recorded its distribution a few times during the summer of 2012 in large (for 5 km around) and small (for 500m around) areas. In addition, we created vegetation maps by conducting field surveys or by obtaining them from existing government data. In the large-scale analysis, the relationship model between the distribution of M. nipponensis and vegetation type from vegetation maps was constructed by using a logistic regression model, and selected best combination of explanatory variables by AIC criterion. Analysis of the large-scale areas revealed that vegetation type such as city, cultivation, and wetland areas around the 600-700m buffer had a statistically negative influence on the M. nipponensis distribution. In the small-scale analysis of density of populations, tall grasslands, forests, and forest edges were found to be important habitats. This study shows that M. nipponensis is vulnerable to environmental changes and is therefore a good environmental indicator species.

Psorodonotus venosus group (Orthoptera, Tettigoniidae; Tettigoniinae): geometric morphometry revealed two new species in the group.

Psorodonotus (Orthoptera, Tettigoniidae) includes 11 species distributed in Caucasus, Anatolia and Balkans. Although its present taxonomy is problematic, mainly three species groups can be distinguished; (i) The Specularis Group, (ii) The Caucasicus Group and (iii) The Venosus Group. Our recent studies on the genus have revealed presence of two new species in the last species group. Morphology of the species group studied both qualitatively and quantitatively using linear metric data of pronotum, tegmina and hind femur, and geometric data of male cerci and ovipositor. Morphological data were accompanied by data obtained from male calling song. Morphological and song data were produced from six different populations from North and Eastern part of Turkey: (1) Hakkari, (2) Tendürek, (3) Giresun, (4) Artvin, (5) Kars and (6) Ağrı. Qualitative and quantitative morphology, either linear-metric or geometric, suggest last three population as members of the same unit, but each of other three as different units. Song data are also largely in support of the morphological results. Necessary illustrations were provided to document results visually. Following conclusions were made: (1) the Artvin, Kars and Ağrı populations represent typical P. venosus and the Giresun population P. rugulosus, (2) each of the Hakkari and Tendürek populations represents a new species and P. hakkari sp. n. and P. tendurek sp. n. described by comparing with other members of P. venosus group, (3) P. rugulosus, P. hakkari sp. n. and P. tendurek sp. n. differ from P. venosus mainly by the longer cerci (extend to or beyond end of abdomen) and indistinct tubercles on surface of pronotal disc in female. P. rugulosus and P. tendurek sp. n. are also similar by sharing presence of two loud elements in a syllable (one in P. venosus, song of P. hakkari sp. n. is not available). But, similarities in phenotype are in conflict with relationships suggested by genetic data.

Sensory evolution of hearing in tettigoniids with differing communication systems

In Tettigoniidae (Orthoptera: Ensifera), hearing organs are essential in mate detection. Male tettigoniids usually produce calling songs by tegminal stridulation, whereas females approach the males phonotactically. This unidirectional communication system is the most common one among tettigoniids. In several tettigoniid lineages, females have evolved acoustic replies to the male calling song which constitutes a bidirectional communication system. The genus Poecilimon (Tettigoniidae: Phaneropterinae) is of special interest because the ancestral state of bidirectional communication, with calling males and responding females, has been reversed repeatedly to unidirectional communication. Acoustic communication is mediated by hearing organs that are adapted to the conspecific signals. Therefore, we analyse the auditory system in the Tettigoniidae genus Poecilimon for functional adaptations in three characteristics: (i) dimension of sound-receiving structures (tympanum and acoustic spiracle), (ii) number of auditory sensilla and (iii) hearing sensitivity. Profound differences in the auditory system correlate with uni- or bidirectional communication. Among the sound-receiving structures, the tympana scale with body size, whereas the acoustic spiracle, the major sound input structure, was drastically reduced in unidirectional communicating species. In the unidirectional P.ampliatus group, auditory sensilla are severely reduced in numbers, but not in the unidirectional P.propinquus group. Within the P.ampliatus group, the number of auditory sensilla is further reduced in P.intermedius which lost acoustic signalling due to parthenogenesis. The auditory sensitivity correlated with the size of the acoustic spiracle, as hearing sensitivity was better with larger spiracles, especially in the ultrasonic range. Our results show a significant reduction in auditory structures, shaped by the differing sex roles during mate detection.

Socially flexible female choice and premating isolation in field crickets (Teleogryllus spp.)

Social influences on mate choice are predicted to influence evolutionary divergence of closely related taxa, because of the key role mate choice plays in reproductive isolation. However, it is unclear whether females choosing between heterospecific and conspecific male signals use previously experienced social information in the same manner or to the same extent that they do when discriminating among conspecific mates only. We tested this using two field cricket sister species (Teleogryllus oceanicus and Teleogryllus commodus), in which considerable information is known about the role of male calling song in premating isolation, in addition to the influence of acoustic experience on the development of reproductive traits. We manipulated the acoustic experience of replicate populations of both species and found, unexpectedly, that experience of male calling song during rearing did not change how accurate females were in choosing a conspecific over a heterospecific male song during playback trials. However, females with acoustic experience were considerably less responsive to male song compared with naïve females. Our results suggest that variation in the acoustic environment affects mate choice in both species, but that it may have a limited impact on premating isolation. The fact that social flexibility during interspecific mate discrimination does not appear to operate identically to that which occurs during conspecific mate discrimination highlights the importance of considering the context in which animals exercise socially flexible mating behaviours. We suggest an explanation for why social flexibility might be context dependent and discuss the consequences of such flexibility for the evolution of reproductive isolation.

Maintaining acoustic communication at a cocktail party: heterospecific masking noise improves signal detection through frequency separation.

We examined acoustic masking in a chirping katydid species of the Mecopoda elongata complex due to interference with a sympatric Mecopoda species where males produce continuous trills at high amplitudes. Frequency spectra of both calling songs range from 1 to 80 kHz; the chirper species has more energy in a narrow frequency band at 2 kHz and above 40 kHz. Behaviourally, chirper males successfully phase-locked their chirps to playbacks of conspecific chirps under masking conditions at signal-to-noise ratios (SNRs) of -8 dB. After the 2 kHz band in the chirp had been equalised to the level in the masking trill, the breakdown of phase-locked synchrony occurred at a SNR of +7 dB. The remarkable receiver performance is partially mirrored in the selective response of a first-order auditory interneuron (TN1) to conspecific chirps under these masking conditions. However, the selective response is only maintained for a stimulus including the 2 kHz component, although this frequency band has no influence on the unmasked TN1 response. Remarkably, the addition of masking noise at 65 dB sound pressure level (SPL) to threshold response levels of TN1 for pure tones of 2 kHz enhanced the sensitivity of the response by 10 dB. Thus, the spectral dissimilarity between masker and signal at a rather low frequency appears to be of crucial importance for the ability of the chirping species to communicate under strong masking by the trilling species. We discuss the possible properties underlying the cellular/synaptic mechanisms of the 'novelty detector'.