Calling Song Research Articles

Ceraeocercus Uvarov, a genus recorded in China for the first time (Orthoptera, Tettigoniidae; Tettigoniinae; Drymadusini).

Ceraeocercus Uvarov, 1910 of Tettigoniinae; Drymadusini is receded in China for the first time. Ceraeocercus fuscipennis fuscipennis Uvarov, 1910 is documented. Morphology and male calling songs are described and illustrations are provided.

Bioacoustics characterization of some anatolian endemic and sub-endemic Katydids (Orthoptera; Tettigoniidae; Bradyporinae, Phaneropterinae and Tettigoniinae).

Seventeen endemic and three sub-endemic species belonging to three subfamilies of Tettigoniidae (Orthoptera: Bradyporinae, Phaneropterinae and Tettigoniinae) were sampled during field trips throughout different regions of Anatolia between 2015 and 2018 (except one taxon). Acoustic parameters of these 20 bush-cricket species affiliated to 12 genera (Apholidoptera, Bradyporus, Decticus, Eupholidoptera, Parapholidoptera, Pezodrymadusa, Pholidoptera, Polysarcus, Psorodonotus, Squamiana, Uvarovistia and Yalvaciana) have been described for the first time in this study. Bioacoustical analysis shows that male calling songs are species-specific for the genera Bradyporus, Parapholidoptera, Pholidoptera, Apholidoptera, Uvarovistia and Psorodonotus. However, there are no distinct differences among species of the genus Pezodrymadusa. Moreover, our additional data on genus Eupholidoptera indicate that there are some different song patterns within the genus. The song description of Uvarovistia zebra presented here is the second bioacoustics data on this genus. The acoustical analyses data support the morpho-species hypothesis of Psorodonotus suphani Taylan Şirin, 2014, which is known from Süphan Mountain (Bitlis province, Eastern part of Turkey) and reject Kaya Çıplak (2017), which recommended it as synonym to P. caucasicus (Fischer von Waldheim, 1846) (commonly known as a Black Sea Region species).

Anaxipha hyalicetra sp. n. (Gryllidae: Trigonidiinae), a new sword-tailed cricket species from Arizona

A new Anaxipha species is described from a locality in southeastern Arizona adjacent to the border with Mexico. The species is unique among the North American fauna by virtue of the broad tegmina, distinctive male genitalia, and calling song phrased in an irregular chirp with a variable pulse train rate. The possibility that the behavioral repertoire of this species includes aggressive song as well as calling song is discussed.

Aggression and Mating Behavior in Wild and Captive Populations of the House Cricket, Acheta domesticus

Animals in captivity experience drastically different selective pressures than their wild counterparts. This can cause evolutionary divergence in behavior between captive and wild populations. While most research on evolution under captivity has focused on vertebrates, we expect similar behavioral changes in insects that live and breed in commercial facilities. Using the common house cricket, Acheta domesticus, we tested how crickets reared in captivity for many generations differed from wild-caught counterparts in two aspects of social behavior: male aggression and female responsiveness to male calling song. Acheta domesticus is an important model organism for behavioral research and are often reared in dense, commercial facilities with ad-libitum access to food and no risk of mortality from predators— very different conditions from the wild. We predicted that commercially-derived males would exhibit less intrasexual aggression due to selection from living in dense conditions. We predicted that commercially-derived females would be less responsive to male calling song because they are more likely to encounter many males at random. Instead, we found that commercially-derived males were more aggressive than wild ones, and that commercially-derived and wild females did not differ in responsiveness to calling song. Insects serve as model systems for a great deal of research in evolutionary and behavioral biology. If these animals are evolving in captivity, they may not provide an accurate representation of the natural phenomena we aim to understand.

Ecophysiological responses to climate change in cicadas

AbstractCicadas are large hemipteran insects characterized by unique life‐history traits, such as extraordinarily long life cycles, a subterranean/terrestrial habitat transition, xylem sap‐feeding and melodious sound production. These fascinating features of cicadas have attracted much attention in the research fields of physiology and ecology, resulting in an accumulation of knowledge about the underlying mechanisms and their adaptive significance. Although community‐level responses to recent climate change have already been documented for cicada fauna, an understanding of their causal relationships is still at the initial stages. In this review, we summarize current knowledge about environmental adaptations of cicadas to facilitate a deeper understanding of the ecophysiological consequences of climate change. We first outline the diverse responses of cicadas to environmental factors, mainly temperature, and their strategies to cope with naturally fluctuating environments. Then, we discuss the consequence of upcoming climate change by consolidating the current findings. This review highlights the fact that fitness‐relevant activities are fine‐tuned to a species‐specific temperature optimum to achieve habitat segregation among coexisting species, implying that cicada diversity is highly susceptible to climate warming. As a result of their conspicuous large bodies and species‐specific calling songs, cicadas are promising candidates for use as bioindicator species to monitor ecological impacts of climate change. We encourage future works that continuously quantify population‐ and community‐level responses to upcoming climate change, as well as unveil mechanistic links between physiological traits and ecological consequences.

Dialects of Metrioptera bicolor (Orthoptera: Tettigonioidea): Intraspecific Acoustic Signal Divergence in a Small-Scale Geographical Distribution

We present an analysis of the calling songs of species Metrioptera bicolor isolated from different locations within Northeast China illustrating the intraspecies calling song divergence. Recording and analysis of the male calling songs of some acoustic characters were performed and five morphological traits of M. bicolor were examined under stereoscope microscope and scanning electron microscope. A cluster analysis was made based on the song properties and the morphology of stridulatory organs. All the song traits, except the pulse number per pulse group, differ distinctly within species collected at different localities, while the pulse number of each pulse group and all the five morphological characters were consistent across locations. The cluster analysis showed that M. bicolor collected from eight sampling sites grouped into two branches and were consistent with geographical distribution.The dialect phenomenon exists in insects and the divergence of acoustic signals occurs in a small-scale geographical region and may be an early stage of speciation. We inferred that the divergence of intraspecific acoustic signals on a small-scale may result from different habitats. This study provides evidence for insect acoustic signal divergence, speciation, and insect acoustic signal evolution.

Taxonomic revision of the genus Xenogryllus Bolívar, 1890 (Orthoptera, Gryllidae, Eneopterinae, Xenogryllini).

Subfamily Eneopterinae has been studied for its diversified acoustic modalities and disjunct distribution. The genus Xenogryllus Bolívar, 1890 is one of the oldest genera of the subfamily, and the first genus of the tribe Xenogryllini. Xenogryllus is known for its low-frequency calling songs and wide distribution across Africa and Asia. It is known from six species and has never been subject to formal taxonomic revision and description of acoustic features of their calling songs is lacking. Therefore, this study consists of a detailed taxonomic revision of all the species. We redescribe or append their taxonomic features using external morphological features and internal genitalic structures. We update the list of Xenogryllus by describing three new spe.

A new species of Landrevinae (Orthoptera) from the Philippines, with notes on Endodrelanva and Endolandrevus (Orthoptera: Gryllidae; Gryllinae; Landrevini).

Owing to the cryptic behavior and morphology of many Southeast Asian Landrevinae, new species are still being discovered in unexplored parts of the region. Here, we describe a new species: Endodrelanva siargaoensis sp. nov. We also recorded and describe the calling song of the new species. Owing to the morphological similarities between species of Endodrelanva Gorochov, 2000 and Endolandrevus Saussure, 1877, we also provide a short review of the two genera and list their characters for comparison.

Genetic divergence, population differentiation and phylogeography of the cicada Subpsaltria yangi based on molecular and acoustic data: an example of the early stage of speciation?

BackgroundGeographical isolation combined with historical climatic fluctuations have been identified as two major factors that contribute to the formation of new species. On the other hand, biotic factors such as competition and predation are also able to drive the evolution and diversification of organisms. To determine whether geographical barriers contributed to population divergence or speciation in the rare endemic cicada Subpsaltria yangi the population differentiation, genetic structure and phylogeography of the species were investigated in the Loess Plateau and adjacent areas of northwestern China by analysing mitochondrial and nuclear DNA and comparing the calling song structure of 161 male individuals.ResultsThe results reveal a low level of genetic differentiation and relatively simple phylogeographic structure for this species, but two independent clades corresponding to geographically isolated populations were recognised. Genetic and geographical distances were significantly correlated among lineages. Results of divergence-time estimation are consistent with a scenario of isolation due to glacial refugia and interglacial climate oscillation in northwestern China. Significant genetic divergence was found between the population occurring in the Helan Mountains and other populations, and recent population expansion has occurred in the Helan Mountains and/or adjacent areas. This population is also significantly different in calling song structure from other populations.ConclusionsGeographical barriers (i.e., the deserts and semi-deserts surrounding the Helan Mountains), possibly coupled with related ecological differences, may have driven population divergence and allopatric speciation. This provides a possible example of incipient speciation in Cicadidae, improves understanding of population differentiation, acoustic signal diversification and phylogeographic relationships of this rare cicada species of conservation concern, and informs future studies on population differentiation, speciation and phylogeography of other insects with a high degree of endemism in the Helan Mountains and adjacent areas.

Behavioural mechanisms of sexual isolation involving multiple modalities and their inheritance.

Speciation research dissects the genetics and evolution of reproductive barriers between parental species. Hybrids are the "gatekeepers" of gene flow, so it is also important to understand the behavioural mechanisms and genetics of any potential isolation from their parental species. We tested the role of multiple behavioural barriers in reproductive isolation among closely related field crickets and their hybrids (Teleogryllus oceanicus and Teleogryllus commodus). These species hybridize in the laboratory, but the behaviour of hybrids is unusual and there is little evidence for gene flow in the wild. We found that heterospecific pairs exhibited reduced rates of courtship behaviour due to discrimination by both sexes, and that this behavioural isolation was symmetrical. However, hybrids were not sexually selected against and exhibited high rates of courtship behaviour even though hybrid females are sterile. Using reciprocal hybrid crosses, we characterized patterns of interspecific divergence and inheritance in key sexual traits that might underlie the mating patterns we found: calling song, courtship song and cuticular hydrocarbons (CHCs). Song traits exhibited both sex linkage and transgressive segregation, whereas CHCs exhibited only the latter. Calculations of the strength of isolation exerted by these sexual traits suggest that close-range signals are as important as long-distance signals in contributing to interspecific sexual isolation. The surprisingly weak mating barriers observed between hybrids and parental species highlight the need to examine reproductive isolating mechanisms and their genetic bases across different potential stages of introgressive hybridization.

The Tree Cricket Neoxabea brevipes Rehn, 1913 (Orthoptera: Gryllidae: Oecanthinae) from the Brazilian southern Atlantic Forest: morphology, bioacoustics and cytogenetics.

In this paper we improve the morphological description of the tree cricket Neoxabea brevipes Rehn, 1913 and a new occurrence record for the species at the São Francisco de Paula National Forest Conservation Unit, State of Rio Grande do Sul, southern Brazil. Morphological characterization is provided together with illustrations emphasizing the most significant diagnostic features, such as the metanotal gland, abdominal specializations and phallic sclerites. The calling song was field recorded, comprising a continuous trill with dominant frequency of 3.6 kHz (19.7°C). The karyotype was described for the first time to Neoxabea Kirby, 1906, including diploid number of 2n=26, with two sexual chromosomes.

Inferring species boundaries using acoustic and morphological data in the ground cricket genus Gymnogryllus (Orthoptera: Grylloidea: Gryllinae)

An important function of song production by male crickets is to attract conspecific females. These sound signals can be used to infer species boundaries as they can provide indirect evidence for reproductive isolation. However, many studies of orthopteran diversity in South-east Asia are based mainly on morphology and only occasionally acoustics. As such, there is a lack of information on how acoustic data can be congruent with morphological data when used to delineate species. Crickets of the genus Gymnogryllus (Grylloidea, Gryllidae), are such an example. Gymnogryllus are relatively speciose, but their calling songs have not been studied. We collected specimens and calling songs of five Gymnogryllus species from South-east Asia. The acoustic parameters of the calls, along with male tegminal venation and morphology genitalia, were compared. All data types showed congruency in distinguishing G. sylvestris and G. leucostictus from each other and from the other species. Inferring species boundaries for G. angustus, G. malayanus, and G. unexpectus using acoustics and tegminal morphometry proves to be more challenging. While acoustics, tegminal morphometry, and genital morphology are likely to be useful for inferring species of Gymnogryllus from different species groups, greater coverage of taxa is needed to resolve taxonomy of closely related Gymnogryllus.

Bioacoustics and morphology of a new bush-cricket species of the genus Isophya (Orthoptera: Phaneropterinae) from Turkey.

A new interesting species of the genus Isophya, I. horon sp. n., is described from Northeastern part of Turkey. The new species can clearly be distinguished from the closely related species by the calling song of male, and morphology. Morphologically, the shapes of the pronotum, tegmina, male cerci and ovipositor are distrinctive. The morphology, song structure and distribution clearly indicate that this new species is a member of the I. zernovi species-group. Additionally, some preliminary data on the male calling songs of closely related species (I. zernovi, I. karadenizensis and I. autumnalis) are also given. In addition, the preliminary data related to spermatophore characteristics (spermatophylax and ampulla weights) and sperm number of the new species are provided.

Phylogeny and acoustic signal evolution of a pure tone song katydid Pseudophyllus titan (Orthoptera: Tettigoniidae) based on the complete mitogenome

Ensifera is an extremely diverse group in the order Orthoptera, and it has been the subject of considerable research, especially in terms of phylogeny and bioacoustics. Katydids are known for using high-frequency broadband signals whereas most cricket songs are pure tones with a frequency range of 2–8 kHz. Pseudophyllus titan is a special katydid emits low-frequency pure tone songs similar to that of crickets. Acoustic communication of Ensifera were widely studied, but song evolution could deserve new examination taking into account the newly available phylogenies. To examine the song evolution of P. titan in the Ensifera, the mitogenomes of P. titan and three other ensiferan species (Sphagniana ussuriana, Oecanthus sinensis, Truljalia hibinonis) were obtained by high-throughput sequencing. In addition, the phylogeny of Ensifera was reconstructed including 63 in-group taxa, and the divergence time was further estimated for major ensiferan lineages. Lastly, the evolutions of song frequency were evaluated based on an ancestral character state reconstruction (ACSR). Moreover, we have studied the calling songs of 78 katydids and performed ACSR based on five genes. All phylogeny analyses confirmed that the superfamily Schizodactyloidea was placed basally to the non-grylloid clade. P. titan was in the Pseudophyllinae clade, and this clade had a distant relationship form other lineages in Phaneropteridae. The ACSR showed that P. titan evolved low-frequency pure tone songs independently after ancestors of katydids evolved high-frequency broadband noise. Referring to the geologic time scale, we suggest that the song frequency evolution in the Ensifera to some extent caused by adaptations to the changing habitat under conditions of climate change and plant evolution.

Evolutionarily conserved coding properties favour the neuronal representation of heterospecific signals of a sympatric katydid species

To function as a mechanism in premating isolation, the divergent and species-specific calling songs of acoustic insects must be reliably processed by the afferent auditory pathway of receivers. Here, we analysed the responses of interneurons in a katydid species that uses long-lasting acoustic trills and compared these with previously reported data for homologous interneurons of a sympatric species that uses short chirps as acoustic signals. Some interneurons of the trilling species respond exclusively to the heterospecific chirp due to selective, low-frequency tuning and “novelty detection”. These properties have been considered as evolutionary adaptations in the sensory system of the chirper, which allow it to detect signals effectively during the simultaneous calling of the sympatric sibling species. We propose that these two mechanisms, shared by the interneurons of both species, did not evolve in the chirper to guarantee its ability to detect the chirp under masking conditions. Instead we suggest that chirpers evolved an additional, 2-kHz component in their song and exploited pre-existing neuronal properties for detecting their song under masking noise. The failure of some interneurons to respond to the conspecific song in trillers does not prevent intraspecific communication, as other interneurons respond to the trill.

Obligate, but not facultative, satellite males prefer the same male sexual signal characteristics as females

Signalling is energetically expensive and increases the risk of predation and parasite infection. To balance the costs and benefits of mate attraction, individuals may adopt an alternative mating strategy such as satellite behaviour, in which nonsignalling males will settle near signalling males and attempt to intercept approaching females. While many suggest that alternative strategies are ‘making the best of a bad job’, little research has examined whether satellites, particularly obligate satellites, have the potential to increase their mating success by preferentially targeting more attractive signallers. Using the Pacific field cricket, Teleogryllus oceanicus, we tested the hypothesis that males are more likely to act as satellites to signalling males with particularly attractive songs, as these callers are likely to attract the most females. In this species, a novel male wing mutation, ‘flatwing’, renders some males unable to call. Flatwings are obligate satellites, while nonmutated, normal-wing males switch between calling and satellite strategies. We presented males with calling song models varying in the percentage of long-to-short chirps, a characteristic important in female choice. As was shown for females in previous work, flatwings exhibited a strong preference for calling songs composed of 60% long chirp. Normal wing males did not prefer any particular calling song model. Our results lead to the paradoxical conclusion that males with highly attractive songs may not have the highest mating success. Such male preference for male sexual signals may oppose selection by females and increase competition between signalling and satellite males. This could potentially slow the rate of male trait evolution and influence the evolution of male competition.

Review of Poecilimon species with inflated pronotum: description of four new taxa within an acoustically diverse group.

Poecilimon Fischer (Orthoptera, Tettigoniidae) consists of about 130 species and a functional taxonomy of the genus requires arranging species into phylogenetic groups. However, this is a task that requires detailed empirical testing. This paper documents data on Poecilimon species with an inflated pronotum. The Poecilimon (Poecilimon) inflatus group is a lineage ranging along a narrow zone in the south-west corner of Anatolia and in Crete plus some other Aegean islands. By producing data of morphology and calling songs of males and responding songs of females the composition and intra-group diversity of P. inflatus group are studied. Both morphology and male calling and female responding songs, exhibited a considerable intra-group diversity. In the light of data obtained the following nomenclatural changes were made. The genus Parapoecilimon Karabağ, 1975 syn. n. is synonymised with Poecilimon Fischer and Parapoecilimon antalyaensis Karabağ, 1975 is given a new combination, Poecilimon antalyaensis (Karabağ, 1975) comb. n. Four new taxa are described in the group: (i) Poecilimon isopterus sp.n.; (ii) Poecilimon inflatus lyciae subsp. n.; (iii) Poecilimon antalyaensis myrae subsp. n., and (iv) Poecilimon antalyaensis anemurium subsp. n. The Poecilimon (P.) inflatus species group consists of the following species: (i) Poecilimon inflatus Brunner von Wattenwyl, 1891; (ii) Poecilimon martinae Heller, 2004; (iii) Poecilimon cretensis Werner, 1903; (iv) Poecilimon antalyaensis (Karabağ, 1975) comb. n.; (v) Poecilimon bilgeri Karabağ, 1953 and (vi) Poecilimon isopterus sp.n. The species group is defined by a combination of characters including the pronotum inflated in metazona and a male cerci mostly black in their apical 1/2-1/3. The male calling song has typically two types of short syllables and the females respond acoustically with very short latency times. By using combination of morphology and song data we suggest three main lineages in the group: (i) P. bilgeri, (ii) P. antalyaensis and (iii) the other four species.

Ultrastructure and electrophysiology of thermosensitive sensilla coeloconica in a tropical katydid of the genus Mecopoda (Orthoptera, Tettigoniidae)

In many acoustic insects, mate finding and mate choice are primarily based on acoustic signals. In several species with high-intensity calling songs, such as the studied katydid Mecopoda sp., males exhibit an increase in their thoracic temperature during singing, which is linearly correlated with the amount of energy invested in song production. If this increased body temperature is used by females as an additional cue to assess the male's quality during mate choice, as has been recently hypothesized (“hot-male” hypothesis), thermosensory structures would be required to evaluate this cue. In the present study, therefore, we investigated the ultrastructure and physiology of thermosensitive sensilla coeloconica on the antennal flagella of Mecopoda sp. using a combination of electron microscopy and electrophysiological recording techniques.We could identify three distinct types of sensilla coeloconica based on differences in the number and branching pattern of their dendrites. Physiological recordings revealed the innervation by antagonistically responding thermoreceptors (cold and warm) and bimodal hygro-/thermoreceptors (moist or dry) in various combinations. Our findings indicate that Mecopoda sp. females are capable of detecting a singing male from distances of at least several centimetres solely by assessing thermal cues.

Inhibitory Pathways for Processing the Temporal Structure of Sensory Signals in the Insect Brain.

Insects have acquired excellent sensory information processing abilities in the process of evolution. In addition, insects have developed communication schemes based on the temporal patterns of specific sensory signals. For instance, male moths approach a female by detecting the spatiotemporal pattern of a pheromone plume released by the female. Male crickets attract a conspecific female as a mating partner using calling songs with species-specific temporal patterns. The dance communication of honeybees relies on a unique temporal pattern of vibration caused by wingbeats during the dance. Underlying these behaviors, neural circuits involving inhibitory connections play a critical common role in processing the exact timing of the signals in the primary sensory centers of the brain. Here, we discuss common mechanisms for processing the temporal patterns of sensory signals in the insect brain.

Paraplangia sinespeculo, a new genus and species of bush-cricket, with notes on its biology and a key to the genera of Phaneropterinae (Orthoptera: Tettigonioidea) from Madagascar

Madagascar is a well-known hotspot of biodiversity. However, many Orthoptera, and especially the Tettigonioidea, belong to little-studied groups. Here we describe a new genus and species of bush-cricket reared from field-collected eggs.Paraplangiasinespeculogen. nov., sp. nov. belongs to Phaneropterinae and shares diagnostic characteristics with members of the tribe Amblycoryphini and its African subtribe Plangiina stat. nov.Paraplangia, which has a chromosome number of 31 X0, differs from other African members of the tribe and subtribe such asEurycoryphaandPlangia, which both have 29 X0. In addition to morphology, we describe the male calling song, female acoustic response, and mating behavior. As calling song, the male produces two series of short syllables. At the end of the second series the female responds with signals of similar duration and spectral composition as the male sounds (peak about 8-9 kHz). To make future identification easier, a key to all genera of Phaneropterinae found in Madagascar is presented.