Search

Communication is fundamental in the animal kingdom, essential to interactions such as mating, defense, and parental care. Vibrational communication has often been overlooked in the past, but in recent decades, it has become clear that insects use substrate vibrations as a communication signal. In burying beetles of the genus Nicrophorus, which are known for their biparental brood care, both parents stridulate. Spending a considerable period of their lives underground, it is very likely the beetles utilize vibrations as part of their communication system. As playback experiments are challenging with this species, this study looked at the physical propagation of the signal of Nicrophorus vespilloides Herbst (Coleoptera: Siliphidae) through three soil types, as well as behavior, to see whether vibrational communication is possible. The aims were to determine: (1) whether the soils used in the laboratory compare to soil from the field, (2) whether the distance of propagation is enough for the range the beetles cover during brood care, (3) whether the two sexes show a difference in stridulation likelihood, (4) whether propagation of defensive signals differs from brood care signals, and (5) whether we can determine a behavior during stridulations that shows a clear and useable reaction to the signal. We manipulated beetles to induce stridulation and then used laser Doppler vibrometers to record the signals using three substrates and various distances, alongside behavioral observations. We showed that the three substrates tested, peat, coconut coir, and forest soil, displayed differences in terms of vibrational propagation, and that burying beetle stridulation signals can be transmitted up to about 25 cm in the soil. We also showed that the location where the animals stridulate exerts a significant influence on the total duration and number of stridulations. Overall, vibrational communication is in principle conceivable in this species, as the signals are transmitted far enough in the natural substrate to allow complex communication, opening possibilities for vibrational communication during this biparental brood care. [ABSTRACT FROM AUTHOR]

Communication plays a fundamental role in the evolution of any form of cooperative behaviour, such as parental care. However, it can be challenging to understand the specific role of certain signals and how they might have evolved into complex communication systems. To investigate what effect a lack of acoustic communication can have on brood care and offspring performance, we silenced parents of biparentally caring burying beetles with a noninvasive method and studied the effect on clutch and offspring performance. Moreover, by analysing three species with varying degrees of offspring dependency on parental care, we aimed to investigate how differing acoustic communication is related to the level of their dependency and if those two align in some way. We used Nicrophorus pustulatus , a nondependent species, Nicrophorus orbicollis , a highly dependent species and Nicrophorus vespilloides , an intermediately dependent species. We found strong effects of silencing parents on offspring performance in all three species. The lack of stridulations impacted offspring weight across all three species. However, our results point towards a difference between species in which development stage communication had the most substantial impact. Looking at larval weight at dispersal, the effects seem to be in line with the larval dependency in the way we would have expected, with N. orbicollis being the most strongly affected, N. vespilloides being also affected and N. pustulatus not being affected. However, looking more closely, we found various differences at other time points and also that larval survival was strongly affected in N. pustulatus. Few studies have looked at the exact function of acoustic signals during brood care with most of them focusing on what type of different signals are emitted rather than what effect they have. Our study is one of the first to start disentangling the interplay of communication and offspring performance. • Silencing parents has a strong effect on offspring performance in burying beetles. • Different species of Nicrophorus differ in communication during brood care. • The larvae of silenced parents are at a disadvantage. • More dependent species do not, per se, rely more on communication. [ABSTRACT FROM AUTHOR]

Circadian rhythms are ubiquitous in nature and endogenous circadian clocks drive the daily expression of many fitness-related behaviors. However, little is known about whether such traits are targets of selection imposed by natural enemies. In Hawaiian populations of the nocturnally active Pacific field cricket (Teleogryllus oceanicus) , males sing to attract mates, yet sexually selected singing rhythms are also subject to natural selection from the acoustically orienting and deadly parasitoid fly, Ormia ochracea. Here, we use T. oceanicus to test whether singing rhythms are endogenous and scheduled by circadian clocks, making them possible targets of selection imposed by flies. We also develop a novel audio-to-circadian analysis pipeline, capable of extracting useful parameters from which to train machine learning algorithms and process large quantities of audio data. Singing rhythms fulfilled all criteria for endogenous circadian clock control, including being driven by photoschedule, self-sustained periodicity of approximately 24 h, and being robust to variation in temperature. Furthermore, singing rhythms varied across individuals, which might suggest genetic variation on which natural and sexual selection pressures can act. Sexual signals and ornaments are well-known targets of selection by natural enemies, but our findings indicate that the circadian timing of those traits' expression may also determine fitness. [ABSTRACT FROM AUTHOR]

Sound production in Passandridae is discovered and the involved structures are described and illustrated using scanning electron microscopy (SEM), revealing a single type of stridulatory apparatus. The phylogenetic significance of this newly described mechanism is discussed based on a finely detailed analysis of representatives from 8 of 9 passandrid genera as well as from five closely related families, which allows hypothesizing the presence of a prosterno-coxal stridulatory apparatus as a unique synapomorphy of the clade comprising all passandrid genera except Aulonosoma Motschulsky. A note on the sound generation mechanism and behaviour is also provided. [ABSTRACT FROM AUTHOR]

Belohina inexpectata Paulian, 1958, the only known representative of Belohinidae (Coleoptera: Scarabaeoidea) and a Madagascan endemic, is redescribed based on recently collected material. Some remarks are provided on its unusual morphology and in particular its mouthparts, with recessed mandibles and membranous epipharynx, its antennae with a V-shaped sensory area and its capsule-like aedeagus, with a regular, unrotated position at rest and the presence of "parameroids". Data on its life history are also provided, including evidence of stridulation. Finally, its phylogenetic position is briefly discussed based on a molecular analysis, which points towards a sister-group relationship with the genus Orubesa (Dynamopodidae), with both taxa together being sister to Hybosoridae. [ABSTRACT FROM AUTHOR]

Silk and hawk moth caterpillars produce a variety of defence sounds described as clicking, chirping, whistling, and vocalising. Such diversity provides opportunity to test hypotheses on the functions and evolution of insect defence sounds using comparative analyses. A key step to conducting comparative analyses is to categorise different phenotypes. Here, we describe mandible sounds of 20 species of late instar Bombycoidea caterpillars and establish objective criteria for differentiating between sound-producing mechanisms. First, we assess how the two mandibular mechanisms – clicking and chirping – differ from one another using two reference species: Antheraea polyphemus (clicker) and Saturnia pyri (chirper). In these references, clicks are produced by ridged and serrated mandibles and have short duration units with few pulses, whereas chirps are produced by scalloped mandibles and have longer duration units with more pulses. Second, we characterise acoustic and morphological traits of 18 additional species. These are categorised as clickers (13 species), chirpers (4 species), or other (1 species) using diagnostic features identified from the reference species. Third, these categorisations are tested using a predictive logistic regression model. The results of this study contribute to our understanding of acoustically mediated defences in caterpillars and provide necessary criteria for conducting further comparative studies. [ABSTRACT FROM AUTHOR]

The evolution of the calling songs in Gomphocerinae was evaluated via estimating a phylogenetic signal of the song characters and an ancestral character state reconstruction. Analyses of the calling songs in 80 palearctic gomphocerine species allowed us to define 24 characters describing the temporal pattern of the sound and the stridulatory leg‐movement pattern. The ancestral song of Gomphocerinae was shown to consist of numerous short echemes lasting on average 0.9 s; each echeme comprised only one syllable produced by movements of only one leg. The next step of the song evolution could be producing longer echemes or longer echeme‐sequence. Later, echeme duration again decreased, but this was accompanied by increasing of echeme or syllable complexity. The characters describing the echeme structure were found to be conservative in their evolution. By contrast, most characters of the syllable temporal structure were shown to be relatively labile and more likely under natural or sexual selection. Our study shows that the song evolution in Gomphocerinae implied not only increasing but also decreasing complexity of the syllable temporal structure. [ABSTRACT FROM AUTHOR]

Katydids produce sound for signaling and communication by stridulation of the tegmina. Unlike crickets, most katydids are known to sing at ultrasonic frequencies. This has drawn interest in the investigation of the biophysics of ultrasonic sound production, detection, evolution, and ecology (including predator-prey interactions) of these katydids. However, most of these studies are based on species from the Neotropics, while little is known about katydid species from the hyperdiverse region of Southeast Asia. To address this, a concerted effort to document, record, and describe the calling songs of Southeast Asian katydids, especially species that call at ultrasonic frequencies, was made. A study spanning two years (2018-2020) in the Malay Peninsula (Singapore and Malaysia), Borneo (Brunei Darussalam and Sabah), and the Philippines revealed previously unknown calls of 24 katydid species from four subfamilies. The calling songs of Southeast Asian katydid species are highly diversified in terms of time and frequency. Call structure can range from isolated syllables (e.g., Holochlora), continuous trills (e.g., Axylus philippinus), to short pulse-trains (e.g., Euanisous teuthroides) and complex echemes (e.g., Conocephalus spp.), with 87.5% of species having ultrasonic peak frequencies and 12.5% being considered extreme ultrasonic callers (peak frequency >40 kHz). The call spectrum ranges from tonal (e.g., spectral entropy is 6.8 in Casigneta sp. 2) to resonant (entropy is 8.8 in Conocephalus cognatus). Of the 24 species whose calls are described here, we imaged and described the soundproducing structures of 18. This study provides a preliminary overview of the acoustic diversity of katydids in Southeast Asia, and the authors hope to inspire further investigation into the bioacoustics of little-known katydids from these areas. Amassing a database of calling songs and soundproducing organ illustrations from different species is important to address taxonomic impediments while advancing our knowledge about the bioacoustics of Southeast Asian katydids. [ABSTRACT FROM AUTHOR]

The Cestrophorini are small katydids of Ecuador’s montane rainforest bearing a prominent awl-shaped fastigium verticis. They are unusual among Conocephalinae in lacking pre-tympanic ear chambers: their eardrums are exposed on their fore tibiae. There are presently two genera, Cestrophorus Redtenbacher, 1891 and Acanthacara Scudder, 1869. Awl-head habitat includes both climax forest and anthropogenically disturbed areas (e.g., pastures, roadsides) on lower slopes in the drainage of the volcanoes Aliso, Chiles and Tungurahua. At night, males perch on low vegetation and stridulate to attract females. To three extant species, we add a further seven, two in Cestrophorus and five in Acanthacara. Male calling songs were recorded and analyzed for all three Cestrophorus species and for three of the Acanthacara spp. We describe and discuss the waveforms of their sinusoid and transient sound pulses in time and frequency domains. [ABSTRACT FROM AUTHOR]

Hypostomus is the most diverse genus within Loricariidae. These catfish species exhibit a very conservative morphology with relatively few external characteristics that differ between different species. In consequence, there is a challenge to understand the distinction of species of this genus. This study aims to describe the sounds produced by ten species of Hypostomus from Araguari River and Paraopeba River (Minas Gerais, Brazil), to examine whether acoustic features could be used to distinguish between the species, and to understand the corresponding sound production mechanisms. The fish were recorded making sounds by holding them in hand underwater, in a glass tank on the river shore next to where they had been caught. All ten species produced sounds, and no effect of body size on acoustic features was observed. Furthermore, the species could not be distinguished using acoustic features. Likewise, all the studied species exhibited similar bony ridges on the dorsal processes of the pectoral spine. Since the sounds produced by the fish do not seem to exhibit interspecific specificity, they do not appear to have a role in behaviours requiring conspecific recognition, such as reproduction. Sound production may have an alarm, distress, or acoustic aposematism function warning predators of the presence of pectoral spines, which have an anti‐predatory function in this clade. [ABSTRACT FROM AUTHOR]

The social parasitic beetle Paussus favieri (Coleoptera, Carabidae, Paussini) performs different types of stridulations, which selectively mimic those emitted by different ant castes of its host Pheidole pallidula (Hymenoptera, Formicidae, Myrmicinae). However, the significance of this acoustical mimicry for the success of the parasitic strategy and the behaviors elicited in the host ants by stridulations was unknown. We reared Paussus favieri in Pheidole pallidula colonies and filmed their interacting behaviors. We analyzed in slow motion the behavior of ants near a stridulating beetle. We analyzed separately trains of pulse (Pa + Pb, produced by repeated rubbings) and single pulse (Pc, produced by a single rubbing) of stridulations, clearly recognizable from the shaking up and down of the beetle hind legs, and associated them with different ant responses. The full repertoire of sounds produced by P. favieri elicited benevolent responses both in workers and soldiers. We found that different signals elicit different (sometimes multiple) behaviors in ants, with different frequency in the two ant castes. However, Pc (alone or in conjunction with other types of pulses) appears to be the type of acoustic signal mostly responsible for all recorded behaviors. These results indicate that the acoustic channel plays a pivotal role in the host–parasite interaction. Finding that a parasite uses the acoustical channel so intensively, and in such a complicated way to trigger ant behaviors, indicates that acoustic signals may be more important in ant societies than commonly recognized. [ABSTRACT FROM AUTHOR]

Bark and ambrosia beetles and pinhole borers (Coleoptera: Curculionidae: Scolytinae and Platypodinae) are two subfamilies of weevils that use acoustic communication within plant tissue. These insects transmit and detect sound in a medium that is neither air nor water and they are among the smallest animals with sound-producing organs. Nevertheless, their sound production is sorely understudied, mostly due to the difficulties associated with acoustically monitoring individuals inside plants. We analysed the stridulatory sounds from 55 bark and ambrosia beetle species within 15 subtribes collected in four countries, making this the largest acoustic dataset of these taxa to date. We characterised and compared the amplitude and spectro-temporal parameters of the distress airborne signals produced by the beetles, in conjunction with phenology and life history data. Sound production was present in 33% of the collected species, of which 60% of these sounds had not been previously reported. Depending on species, either both sexes stridulated or only one. Some species had calls with different acoustic morphotypes (one, two, or three notes), and when both sexes stridulated, sounds generally differed. Our data suggest that type of mating system and size play an important role in determining the acoustic communicatory capacity of most species. [ABSTRACT FROM AUTHOR]

The biology and seasonal phenology of Aacanthocnema dobsoni (Froggatt) were studied at a single site in Victoria over a 2 year period between 2013 and 2015. This species is monophagous on the dioecious host, Allocasuarina verticillata (Lam.) L. Johnson (Casuarinaceae). Laboratory studies found that females attained reproductive maturity 24 h post‐eclosion, lived for 28.6 ± 2.8 (mean ± SE) days and laid 182 ± 23 (mean ± SE) eggs each. Egg development was most rapid at 26 °C, ceased below 7 °C and above 33 °C; hatching required 188 degree‐days. Nymphs could not be reared to adulthood on excised host branchlets maintained under controlled conditions, so no developmental data were obtained for these life stages. Seasonal phenology data revealed pronounced developmental asynchrony, i.e. with overlapping generations and multiple life stages occurring simultaneously. Three generations per year were observed, and there was no evidence of either developmental (egg and nymph) or reproductive diapause. A 4 day heat wave in January 2014 drastically reduced psyllid abundance at the study site and the size of the adults that eclosed from the surviving nymphs. These smaller adults produced substrate‐borne vibrational signals with altered characteristics, i.e. with significantly higher intensities and power. The altered signals might have facilitated communication over longer distances and increased mate finding opportunities when populations were low. The abundance of adults had recovered to preheat wave levels 3 months after the heat wave. High fecundity, multivoltinism and effective mate attraction signalling are life history traits that may mitigate against localised extinction of populations as a consequence of extreme weather events. [ABSTRACT FROM AUTHOR]

Hygrobiidae, or squeak beetles, originated in the Triassic-Jurassic and exhibit a relictual distribution in the Palaearctic, Oriental and Australasian regions. Hygrobiids are well known for their sound-producing abilities, although studies of their bioacoustics remain limited. Here we describe sound producing organs and bioacoustics of the Palaearctic Hygrobia hermanni (Fabricius, 1775). Plectra and pars stridens were examined in both sexes, and sound characteristics analysed. Despite small differences between male and female last abdominal ventrites, plectra were identical. Pars stridens, however, differed subtly, tooth ridges being wider in females. Calls of both sexes were harmonic, with peak frequency at 6.1 kHz, and secondary peak at 10.9 kHz; males exhibiting longer inter-chirp intervals. Calls changed with time in the laboratory, this possibly condition-related effect being more apparent in males. The differences found between sexes suggest that sound production in squeak beetles may function in intraspecific communication, in addition to being an antipredator device. [ABSTRACT FROM AUTHOR]

Blue catfish Ictalurus furcatus, the largest catfish in North America and an invasive species in Chesapeake Bay estuaries, has experienced explosive population growth, negatively impacting native species. They have strong pectoral spines that can be locked and rubbed against the pectoral girdle to produce stridulation sounds although sound production during behavioral interactions is unstudied. We examined agonistic behavior in juveniles by allowing individuals to establish a territory and introducing an intruder. Big (43–50 cm total length) and small (36–41 cm) fish were paired within and across size ranges. Territory was considered established when a fish remained in its shelter for over an hour. Fish typically entered the shelter head first and maintained that orientation. They used a variety of agonistic behaviors in shelter defense including aggressive contact, caudal sweeping, and standoff but not the production of stridulation sounds. Individuals often utilized different behaviors indicating less stereotypy than in many fishes, and there were differences in incidence of behaviors between big and small fish. Residents and larger fish did not always win, perhaps due to juvenile status and low fitness consequences of territorial possession. [ABSTRACT FROM AUTHOR]

Strident lobsters of the Palinuridae family emit sounds in the presence of predators that can be used in the acoustic monitoring of such species. This study aims to identify sound emission and describe the structures of sound mechanism in red (Panulirus meripurpuratus) and green (Panulirus laevicauda) Brazilian spiny lobsters. The lobsters were collected in the environment, and recordings were performed in laboratory tanks with submerged hydrophones. The animals were stimulated to emit sound by the presence of an artificial octopus in the tank. The sounds emitted by the lobsters were analyzed by means of the waveform, and the structures involved (plectrum and file) were observed using scanning electron microscopy (SEM). Both species emitted a rasp sound composed of several pulses, with a rate varying from 125 to 265 pulses per second. The SEM showed that the file is similar between the species and it is covered by microscopic plates (shingles) measuring between 12.6 and 12.9 μm of medial–lateral width and 6.2 μm and 7.1 μm of anteroposterior length. This analysis also revealed for the first time the presence of pores (< 1 μm in diameter) with vestiges of cuticular setae in-between the shingles, which could be involved in the mechanosensory control of sound production in lobsters. The results of this study corroborate the morphological pattern of sound emission structure described for other lobsters of the genus Panulirus. [ABSTRACT FROM AUTHOR]

In a sexual context, it is expected that females base their choice of mate on the behaviours that males perform during courtship, as such behaviours are associated with the male's mate quality. Stridulation is one form of female communication in arthropods, for example, spiders. In spiders, stridulation during sexual interactions is relatively common in some groups but mainly restricted to males. In the pholcid spider Holocnemus pluchei (Pholcidae), both sexes have stridulatory organs. The aims of the present work were to: (a) determine possible differences in the frequency of occurrence of stridulation between females during inter‐sexual interactions, (b) establish female consistency in stridulation along repeated interactions and (c) analyse if female stridulation is associated with certain male behaviours during pre‐copulatory courtship and with male size. Female H. pluchei showed highly repeatable differences in their frequency of stridulation across consecutive encounters with males (ICC = 0.64). However, only a modest level of repeatability was detected in total time females spent stridulating across trials (ICC = 0.19). Females' mean stridulatory behaviour did not change across ten consecutive trials spread across 20 days, and their behaviour was apparently unaffected by male persistence of copulatory attempted and/or size. These results imply that the frequency of female stridulatory behaviour is a trait that is highly characteristic of each individual. Finally, our work opens the door to determine whether behavioural consistency manifests in other ecological contexts and their functional implications. [ABSTRACT FROM AUTHOR]

Highlights • Accelerometer is an efficient tool to monitor the acoustic behaviour of P. elephas. • Low accelerometer sample frequencies don't influence detection of acoustic events. • Low accelerometer sample frequencies increase the error on pulses estimation. • Accelerometer data let to separate acoustic from behavioural events of P. elephas. Abstract The European spiny lobster Palinurus elephas emits sound ("rasp"), moving the base of their antennas, as response to the presence of predator and for interspecific communication. During the last decade, three-axial accelerometers have been used to mainly describe diel activity patterns, circadian rhythms and rate of energy consumption of different lobster species, but these devices can also record sound emission in terms of mechanical vibration of carapace. In order to evaluate the efficiency of accelerometers in recording sound production (rasp events and number of pulses inside each rasp) and in discriminating of that from other behavioural events, accelerometers were used in combination with hydrophone and during mesocosm free ranging conditions. Three-axial accelerometers were able to detect sound production events in P. elephas. All the rasp events (n = 405) recorded with hydrophones were also detected by the accelerometers considering its data sampled at different frequency (from 800 Hz to 12 Hz). However, the detection of the number of pulses within each rasp sound decreased with sampling frequency of accelerometer data (median of predictive error for 800 Hz = 0.33; median of predictive error for 12 Hz = 0.65). During mesocosm free condition, three behavioural categories were identified: walk, tail flip, and rasp, the last with averaged (15.16 ± 3.52 m/s2) and maximum (29.49 ± 9.37 m/s2) values of acceleration significantly higher than the other two. Findings from this study prove that accelerometers register only lobster body vibrations providing a clear signal that is not distorted by other noises in the environment. They also allowed to identify rasps for each tagged lobster, something not possible using hydrophones in both, aquaria or natural habitat. Accelerometer resulted an useful tool to detect behaviours even with low mobility species. Moreover, the possibility to couple accelerometer and other biologging techniques would help to improve our understanding of the behaviour of a large range of free-living species. [ABSTRACT FROM AUTHOR]

Many insects vary their song patterns to communicate different messages, but the underlying biomechanisms are often poorly understood. Here, we report on the mechanics of sound production and variation in an elytro-tergal stridulator, male Dendroctonus valens bark beetles. Using ablation experiments coupled with high-speed video and audio recordings, we show that: (1) chirps are produced using a stridulatory file on the left elytron (forewing) and a protrusion (plectrum) on the seventh abdominal segment; (2) chirps are produced by 'spring stridulation', a catch-and-release mechanism whereby the plectrum catches on a file tooth and, upon release, springs forward along the file; and (3) variability in chirp types is caused by introducing multiple catch-and-release events along the file to create regular interruptions. These results provide experimental evidence for the mechanics of elytro-tergal stridulation, and provide insight into how an insect can incorporate variability into its acoustic repertoire using a spring-loaded mechanism. [ABSTRACT FROM AUTHOR]

Many insects vary their song patterns to communicate different messages, but the underlying biomechanisms are often poorly understood. Here we report on the mechanics of sound production and variation in an elytro-tergal stridulator, male Dendroctonus valens bark beetles. Using ablation experiments coupled with highspeed video and audio recordings, we show that: 1. chirps are produced using a stridulatory file on the left elytron (forewing) and a protrusion (plectrum) on the seventh abdominal segment; 2. chirps are produced by 'spring stridulation', a catchand- release mechanism whereby the plectrum catches on a file tooth, and upon release, springs forward along the file; and 3. variability in chirp types is caused by introducing multiple catch-and-release events along the file to create regular interruptions. These results provide experimental evidence for the mechanics of elytro-tergal stridulation, and provide insight into how an insect can incorporate variability into its acoustic repertoire using a spring-loaded mechanism. [ABSTRACT FROM AUTHOR]

Asian genera and species of the plant bug tribe Hallodapini are reviewed. The present classification system is based particularly on detailed morphology and function of the stridulatory device and concealed habitat preference. Our recent efforts successfully demonstrated that the stridulatory devices of the forewing edge and dorsal metafemur are doubtlessly used for intraspecific communication (at least for courtship behavior). Based on the stridulatory structures and additional characters, Cleotomiris Schuh, 1995, Cleotomiroides Schuh, 1984, Hallodapus Fieber, 1858 and Wygomiris Schuh, 1984, are re-diagnosed and discussed; Alloeomimella Yasunaga & Duwal gen. nov. is proposed to accommodate Alloeomimus muiri Schuh, 1984 and a new combination, Alloeomimella muiri (Schuh) comb. nov., is accordingly established. Six new species are further described: Cleotomiroides ishikawachui Yasunaga & Duwal sp. nov. (Indonesia: Java); Hallodapus jingfui Yasunaga & Duwal sp. nov. (Taiwan); H. spinosus Yasunaga & Duwal sp. nov. (Thailand); H. susurratus Yasunaga & Duwal sp. nov. (Thailand); Wygomiris paveli sp. nov. (Taiwan); and W. phormictes sp. nov. (Taiwan). The male of Wygomiris nanae Yasunaga, 2012 is reported for the first time. A teratological form found on the antennae in two Wygomiris species is also documented. [ABSTRACT FROM AUTHOR]

Pupae of numerous Papilionidae and Nymphalidae produce twitter sounds when wriggling in response to mechanical stimulation. The structural basis comprises distinct pairs of sound-producing organs (SPOs) located at intersegmental membranes of the abdomen. They differ—as the twitters do—in sampled taxa of Papilioninae, Epicaliini, and Heliconiini. The opposing sculptured cuticular sound plates (SPs) of each SPO appear structurally the same but are actually mirror-images of each other. Results suggest that sounds are not generated by stridulation (friction of a file and a scraper) but when these inversely sculptured and interlocking surfaces separate during pupal wriggling, representing a stick-slip mechanism. Twitter sounds comprise series of short broadband pulses with the main energy in the frequency range 3–13 kHz; they can be heard by humans but extend into ultrasonic frequencies up to 100 kHz. [ABSTRACT FROM AUTHOR]

Male katydids produce mating calls by stridulation using specialized structures on the forewings. The right wing (RW) bears a scraper connected to a drum-like cell known as the mirror and a left wing (LW) that overlaps the RW and bears a serrated vein on the ventral side, the stridulatory file. Sound is generated with the scraper sweeping across the file, producing vibrations that are amplified by the mirror. Using this sound generator, katydids exploit a range of song carrier frequencies (CF) unsurpassed by any other insect group, with species singing as low as 600 Hz and others as high as 150 kHz. Sound generator size has been shown to scale negatively with CF, but such observations derive from studies based on few species, without phylogenetic control, and/or using only the RW mirror length. We carried out a phylogenetic comparative analysis involving 94 species of katydids to study the relationship between LW and RW components of the sound generator and the CF of the male's mating call, while taking into account body size and phylogenetic relationships. The results showed that CF negatively scaled with all morphological measures, but was most strongly related to components of the sound generation system (file, LW and RW mirrors). Interestingly, the LW mirror (reduced and nonfunctional) predicted CF more accurately than the RW mirror, and body size is not a reliable CF predictor. Mathematical models were verified on known species for predicting CF in species for which sound is unknown (e.g. fossils or museum specimens). [ABSTRACT FROM AUTHOR]

In katydids (Orthoptera: Tettigonioidea) of the subfamily Phaneropterinae females ready to mate initiate a duet, announcing her position to the male singer, but also potentially to eavesdropping rivals. In many species the male seems to defend the communication by adding self-produced imitations of a female response. If these signals occur within the male sensory time-window after the female song, they can disturb the orientation of rivals. In two species of the genus Gonatoxia, males and females use short, relatively narrow-banded sounds (width 2-7 kHz 10 dB below peak). Male song and female response, however, differ considerably in peak frequency. In G. maculata, the peak frequency of the last part of the male song (13 kHz) is between that of the first part (15 kHz) and the female response (9 kHz), in G. helleri the last part (9 kHz; assumed imitation) and the female song are identical in peak frequency and by a factor two lower than the first part (19 kHz). The male stridulatory file of this species is correspondingly modified and differs from all other members of the genus. The imitation of spectral properties of the female response is not known from any other katydid. [ABSTRACT FROM AUTHOR]

In the hind wings ofYponomeutaand related genera there are transparent patches without scales; within these are arrays of ridges and it is suggested these may be used to produce sounds, with the adjacent membrane acting as a resonator. Avenues for further research are explored, together with potential taxonomic implications. [ABSTRACT FROM PUBLISHER]

Male grigs, bush crickets and crickets produce mating calls by tegminal stridulation: the scraping together of modified forewings functioning as sound generators. Bush crickets (Tettigoniidae) and crickets (Gryllinae) diverged some 240 million years ago, with each lineage developing unique characteristics in wing morphology and the associated mechanics of stridulation. The grigs (Prophalangopsidae), a relict lineage more closely related to bush crickets than to crickets, are believed to retain plesiomorphic features of wing morphology. The wing cells widely involved in sound production, such as the harp and mirror, are comparatively small, poorly delimited and/or partially filled with cross-veins. Such morphology is similarly observed in the earliest stridulating ensiferans, for which stridulatory mechanics remains poorly understood. The grigs, therefore, are of major importance to investigate the early evolutionary stages of tegminal stridulation, a critical innovation in the evolution of the Orthoptera. The aim of this study is to appreciate the degree of specialization on grig forewings, through identification of sound radiating areas and their properties. For well-grounded comparisons, homologies in wing venation (and associated areas) of grigs and bush crickets are re-evaluated. Then, using direct evidence, this study confirms the mirror cell, in association with two other areas (termed 'neck' and 'pre-mirror'), as the acoustic resonator in the grig Cyphoderris monstrosa. Despite the use of largely symmetrical resonators, as found in field crickets, analogous features of stridulatory mechanics are observed between C. monstrosa and bush crickets. Both morphology and function in grigs represents transitional stages between unspecialized forewings and derived conditions observed in modern species. [ABSTRACT FROM AUTHOR]

New distribution data on Orthoptera of Greece are presented. Acrometopa servillea (Brullé, 1832), Platycleis grisea (Fabricius, 1781) and Poecilimon propinquus Brunner von Wattenwyl, 1878 are reported as new to Mt. Kitheron, the last one also as new to Nomos Biotias. Anterastes serbicus Brunner von Wattenwyl, 1882 and Ephippiger ephippiger ephippiger (Fiebig, 1784) are reported as new to Mt. Vrondous. Platycleis escalerai escalerai Bolivar, 1899, Incertana incerta (Brunner von Wattenwyl, 1882), Eupholidoptera kykladica Heller, Willemse and Willemse, 2009 and Eumodicogryllus bordigalensis bordigalensis (Latreille, 1804) are new to Attiki. The last two are also new to Sterea Ellas. Platycleis affinis affinis Fieber, 1853, is new to Kiklades. Gryllus (Gryllus) campestris Linnaeus, 1758, Xya variegata (Latreille, 1809) and Xya pfaendleri Harz, 1970 are new records for Nomos Serron. Trigonidium (Trigonidium) cicindeloides Rambur, 1838 is reported as new to Macedonia. We confirm the presence of Mogoplistes brunneus Serville, 1838 at the Aegean Sea. Lastly, Paranocarodes chopardi Pechev, 1965 is reported as new to Macedonia and sound production in that species is discussed for the first time. [ABSTRACT FROM AUTHOR]

During sexual selection members of the opposite sex utilize a variety of signal modalities to acquire information about potential mates. As a prerequisite, signal modalities must exhibit intraspecific variation and correlate with desirable traits that reflect the fitness of the signaller. Anecdotal accounts suggest that female psyllids (Hemiptera: Sternorrhyncha) utilize substrate-borne vibrations (SBVs) to choose between males. However, comprehensive studies investigating the role of SBVs in Psylloidea are lacking. We used laser vibrometry and playback experiments to study the mating and calling behaviours of a psyllid, Aacanthocnema dobsoni (Triozidae). Specifically, we quantified call parameters and asked whether they vary intraspecifically and correlate with male body size and age. We also tested whether female responsiveness is influenced by the body size and age of calling males. Calls were sex-specific: male calls were more complex and comprised long and short syllables while female calls comprised only short syllables. Temporal and spectral parameters of male calls differed significantly from those of female calls. Calls of both sexes exhibited a high level of intraspecific variation. Larger males produced calls with a lower dominant frequency and older males produced calls of higher intensity and pulse rate. We used playback to test female responsiveness to calls recorded from males of contrasting sizes and ages. Surprisingly, female responsiveness was not influenced by body size or the age of calling males. Interestingly, females are polyandrous but only virgins called or responded to male calls. Conversely, males called frequently and attempted (and often succeeded) to mate with unresponsive females. These results demonstrate that A. dobsoni utilizes SBVs for mate attraction but not for precopulatory mate selection. We suggest that polyandry in A. dobsoni potentially evolved in response to male harassment and, as a consequence of polyandry, sexual selection is probably achieved via postcopulatory sexual selection mechanisms. [ABSTRACT FROM AUTHOR]

Male field crickets generate calls to attract distant females through tegminal stridulation: the rubbing together of the overlying right wing which bears a file of cuticular teeth against the underlying left wing which carries a sclerotized scraper. During stridulation, specialized areas of membrane on both wings are set into oscillating vibrations to produce acoustic radiation. The location of females is unknown to the calling males and thus increasing effective signal range in all directions will maximize transmission effectiveness. However, producing an omnidirectional sound field of high sound pressure levels may be problematic due to the mechanical asymmetry found in this sound generation system. Mechanical asymmetry occurs by the right wing coming to partially cover the left wing during the closing stroke phase of stridulation. As such, it is hypothesized that the sound field on the left-wing side of the animal will contain lower sound pressure components than on the right-wing side as a result of this coverage. This hypothesis was tested using a novel method to accurately record a high-resolution, three dimensional mapping of sound pressure levels around restrained Gryllus bimaculatus field crickets singing under pharmacological stimulation. The results indicate that a bilateral asymmetry is present across individuals, with greater amplitude components present in the right-wing side of the animal. Individual variation in sound pressure to either the right-or left-wing side is also observed. However, statistically significant differences in bilateral sound field asymmetry as presented here may not affect signalling in the field. [ABSTRACT FROM AUTHOR]

Acoustic signals are commonly used by insects in the context of mating, and signals can vary depending on the stage of interaction between a male and female. While calling songs have been studied extensively, particularly in the Orthoptera, much less is known about courtship songs. One outstanding question is how potential mates are differentiated by their courtship signal characteristics. We examined acoustic courtship signals in a new system, bark beetles (Scolytinae). In the red turpentine beetle ( Dendroctonus valens ) males produce chirp trains upon approaching the entrance of a female's gallery. We tested the hypotheses that acoustic signals are honest indicators of male condition and that females choose males based on signal characteristics. Males generated two distinct chirp types (simple and interrupted), and variability in their prevalence correlated with an indicator of male quality, body size, with larger males producing significantly more interrupted chirps. Females showed a significant preference for males who produced interrupted chirps, suggesting that females distinguish between males on the basis of their chirp performances. We suggest that interrupted chirps during courtship advertise a male’s size and/or motor skills, and function as the proverbial ‘passwords’ that allow him entry to a female's gallery. [ABSTRACT FROM AUTHOR]

The bat-eared fox is an insectivorous, nocturnal predator that uses its characteristic large ears to detect sounds made by invertebrate prey. Behavioural observations of the bat-eared fox emphasize the significant role hearing plays in insect prey detection and localization. In turn, katydids are nocturnal insects that risk attracting predators by producing conspicuous signals for mate attraction and pair formation. To determine the interaction and potential level of predation between this listening, insectivorous predator with acoustically active katydids, behavioural observations and scat collection from bat-eared fox individuals were conducted in the Western Cape, South Africa. Acoustic surveys were also conducted to identify acoustic species within foraging areas of bat-eared foxes and assist with identifying their remains in scat. Results indicated that bat-eared foxes have a broad, opportunistic diet. Despite the fox's hearing ability, and its use of sound to detect insect prey, acoustically active species were not consumed as part of the bat-eared fox diet. Instead, acoustically mute invertebrates such as most beetles and cockroaches were the dominant prey, followed by fruit and vertebrate prey, such as lizards, small mammals and nestlings. Although there was a diverse acoustic assemblage of katydids across the landscape, their absence within the bat-eared fox diet may either reflect a preference for other prey, or suggests highly developed anti-predator behaviour found within this insect group in which predation pressure has been a major evolutionary driver. It is likely that both apply, and currently bat-eared foxes find foraging on other prey more optimal. [ABSTRACT FROM AUTHOR]

Crickets carry wind-sensitive mechano-receptors on their cerci, which, in response to the airflow produced by approaching predators, triggers escape reactions via ascending giant interneurons (GIs). Males also activate their cercal system by air currents generated due to the wing movements underlying sound production. Singing males still respond to external wind stimulation, but are not startled by the self-generated airflow. To investigate how the nervous system discriminates sensory responses to self-generated and external airflow, we intracellularly recorded wind-sensitive afferents and ventral GIs of the cercal escape pathway in fictively singing crickets, a situation lacking any self-stimulation. GI spiking was reduced whenever cercal wind stimulation coincided with singing motor activity. The axonal terminals of cercal afferents showed no indication of presynaptic inhibition during singing. In two ventral GIs, however, a corollary discharge inhibition occurred strictly in phase with the singing motor pattern. Paired intracellular recordings revealed that this inhibition was not mediated by the activity of the previously identified corollary discharge interneuron (CDI) that rhythmically inhibits the auditory pathway during singing. Cercal wind stimulation, however, reduced the spike activity of this CDI by postsynaptic inhibition. Our study reveals how precisely timed corollary discharge inhibition of ventral GIs can prevent self-generated airflow from triggering inadvertent escape responses in singing crickets. The results indicate that the responsiveness of the auditory and wind-sensitive pathway is modulated by distinct CDIs in singing crickets and that the corollary discharge inhibition in the auditory pathway can be attenuated by cercal wind stimulation. [ABSTRACT FROM AUTHOR]

A new stridulatory structure for Carabidae, based on morphology and acoustics of the Southern Hemisphere genus Gonogenia, is described. Sound is produced by abdomino--elytral movement between the surfaces of two projections on the inner lateral surface of the elytra (pars stridens) against the surfaces of two opposing projections from the outer edges of the first abdominal sternite (plectrum). While both males and females have stridulatory organs, only males were recorded producing signals. Signals were broad spectrum extending into ultrasound frequency ranges (3.5-75 kHz). Signals were produced continually by male Gonogenia tabida individuals while mobile in a localized area and likely represent a form of intraspecific communication, due to absence of observed potential disturbance stimuli. [ABSTRACT FROM AUTHOR]

This paper illustrates the biomechanics of sound production in the neotropical predaceous katydid Arachnoscelis arachnoides (Insecta: Orthoptera: Tettigoniidae). Described and previously known from only one male specimen, this genus of predaceous katydids resembles spiders in their general body appearance. To call distant females, male katydids produce songs by stridulation where one forewing possessing a sclerotized file rubs against a row of teeth (scraper) on the other wing. In most katydid species, the songs are produced during the wing-closing phase of the stridulation. Morphological comparative studies of the stridulatory apparatus of the type specimen ofArachnoscelis arachnoides and males of other closely related species suggest that this insect sings with a frequency of ca. 80 kHz to attract conspecific females. We found an abundant population of A. arachnoides in Central Northeast of Colombia and undertook a complete analysis of the biomechanics of stridulation in this species. Using ultrasound-sensitive equipment and high-speed video, we determined that male A. arachnoides sing at ca. 74 kHz and use elastic energy and wing deformation to reach such ultrasonic frequencies. In contrast to most katydids, males of this species produce their calls during the opening phase of the wing; this form of stridulation is discussed. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Guadeloupe, the largest of the Leeward Islands, harbors three species of Pseudophyllinae (Orthoptera: Tettigoniidae) belonging to distinct tribes. This study examined the basic aspects of sound production and acousto-vibratory behavior of these species. As the songs of many Pseudophyllinae are complex and peak at high frequencies, they require high quality recordings. Wild specimens were therefore recorded ex situ. Collected specimens were used in structure-function experiments. Karukerana aguilari Bonfils (Pterophyllini) is a large species with a mirror in each tegmen and conspicuous folds over the mirror. It sings 4-6 syllables, each comprising 10-20 pulses, with several peaks in the frequency spectrum between 4 and 20 kHz. The song is among the loudest in Orthoptera (> 125 dB SPL in 10 cm distance). The folds are protective and have no function in song production. Both mirrors may work independently in sound radiation. Nesonotus reticulatus (Fabricius) (Cocconotini) produces verses from two syllables at irregular intervals. The song peaks around 20 kHz. While singing, the males often produce a tremulation signal with the abdomen at about 8-10 Hz. To our knowledge, it is the first record of simultaneous calling song and tremulation in Orthoptera. Other males reply to the tremulation with their own tremulation. Xerophyllopteryx fumosa (Brunner von Wattenwyl) (Pleminiini) is a large, bark-like species, producing a syllable of around 20 pulses. The syllables are produced with irregular rhythms (often two with shorter intervals). The song peaks around 2-3 kHz and 10 kHz. The hind wings are relatively thick and are held between the half opened tegmina during singing. Removal of the hind wings reduces song intensity by about 5 dB, especially of the low frequency component, suggesting that the hind wings have a role in amplifying the song. [ABSTRACT FROM AUTHOR]

Insects make use of sound in a variety of behavioral and reproductive contexts. Acoustic signals are known to serve in defense, sexual advertisement, prey location, and in cooperative activities such as offspring care and group foraging. In airborne signals produced by insects, information associated with species identification is often related to the temporal structure of the sound, while spectral quality is more closely associated with intraspecific variation. The Nierophorine burying beetles (Insecta: Coleoptera: Silphidae) are a group known to produce sound through dorso-ventro stridulation, but the bioacoustics of this group remains understudied. Here, we examine the stridulatory sound produced by eight North American species of Nicrophorus burying beetles, testing the hypothesis that interspecific differences will be encoded in temporal characteristics of the sound, and that signal divergence will be explained by one of three mechanisms: selection as an intraspecific signal, selection for interspecific aposematism, or random divergence through drift. We digitally recorded stridulation in each species, and analyzed recordings to describe each in respect to four spectral and eight temporal acoustic characters. All species produced a low amplitude biphastic sound pulse consisting of from 58 to 126 syllables, and exhibiting weak dominant frequencies (5.8-12.7 kHz). Collapsing the 12 variables into three rotated t:actors using principal component analysis, we found no sex-related differences in sound, but significant interspecies divergence in respect to all three factors. We constructed a phylogeny for the group based on the morphology of the stridulatory structures and the acoustic characters, and found weak support for an intraspecific signal divergence model. [ABSTRACT FROM AUTHOR]

Stridulation patterns and stridulatory organ were rarely investigated in the parasitoid family Mutillidae, and data still lack for any sex or species in many subfamilies. We described the morphology of stridulatory organ and the distress call of Myrmilla capitata (Myrmillinae), a small mutillid wasp in which both sexes are apterous. As in other mutillids, the stridulation is produced by rubbing a scraper on the gaster tergite II against a file on gaster tergite III and consists of sequences of pulse trains organized in two subunits (disyllabic chirps) characterized by pulses with opposite phase. Overall, sexes differed in few morphological and acoustical traits. In particular, females had wider and longer files (due to the larger tergite III), smaller ridge thickness, greater inter-ridge distance and produced sound with lower maximum frequencies. This is in accordance to the fact that individuals with wider files, and files with thicker and more separated ridges, tend to emit sounds reaching lower frequencies. Both sexes, on average, seemed to "use" about 50% of the ridges while stridulating, and the file is moved against the scraper with an average speed of about 6 mm/s. Syllable duration and pulse rate (number of pulses/s) were also affected by some morphological traits of the file. Thus, intra-specific variation in the morphology of the stridulatory organ affects stridulation features in this small velvet ant with relatively weak sexual dimorphism. [ABSTRACT FROM AUTHOR]

The calling song of the cricketsPhylloscyrtus amoenusandCranistus colliuridesare described and compared for the first time. These species are sympatric, and stridulate at the same time at day/night on shrubs and grasses surrounding a Brazilian semi-deciduous forest in the state of Rio Grande do Sul. We analyzed the dominant frequency and temporal parameters of the calling song of both species in order to clarify parameters that allow the sound to be effective in attracting conspecific mates. We found that their calling song was a continuous trill with the same dominant frequency, but temporal parameters such as pulse period, pulse rate and sound cycles per pulse were different, suggesting females could use them to find specific mates. [ABSTRACT FROM PUBLISHER]

Subterranean ant nests are structures that emerge from collective building. The mechanisms used by individual ant workers to coordinate their building behaviour are largely unknown. We discovered that isolated workers of the Chaco leaf-cutting ant Atta vollenweideri stridulate while excavating in soil, and we investigated the possibility that workers communicate via vibrational signals in the context of collective nest excavation. Workers were observed to stridulate at similar rates, not only while manipulating soil with their mandibles, but also several seconds before grabbing the material. The measured attenuation rate suggests a detectable signal range of less than 6cm. When presented with stridulation signals in an experimental arena offering distinct locations to excavate, workers were more likely to dig close to the source than at an alternative site. The probability of a worker digging at a location increased with the intensity of the vibrational signals produced at this location. Group-level stridulatory activity was monitored in the context of nest enlargement, in which ants excavating a tunnel were allowed suddenly to break into an existing chamber. Recordings before and after having gained access to the chamber showed that workers stridulated while excavating, but gradually discontinued signal production when nest space was available. Our results indicate that beyond the previously described use of vibrational signals in the contexts of food recruitment and alarm communication, workers stridulate while engaged in nest digging and attract nestmates to join excavation activity at the same location, thus contributing to the spatial organization of collective nest building. [ABSTRACT FROM AUTHOR]

The Hemiptera displays a notable diversity of vibratory communication signals across its various families. Here we describe the substrate and airborne vibrations (sounds), the mechanism of production, and associated behaviors of Jadera haematoloma Herrich-Schaeffer, a member of the family Rhopalidae. Adult males and females both produce short, stereotyped sound bursts by anterior-posterior movement of abdominal tergites I and II against a stridulitrum located on the ventral surface of the metathoracic wing. Sound bursts are produced by a single adult male or female when physically touched by another adult, and are strongly associated with being crawled on by the approaching individual, but are not produced in response to contact with other arthropods or when pinched with forceps. The propensity to produce sounds when crawled upon decreases during the mating season. These sound bursts by J. haematoloma likely are communication signals. Rhopalidae has been significantly absent from the vibratory communication literature until now. Although the sounds are produced using a mechanism common to vibratory communication systems in closely related Heteropteran Hemiptera, the sounds in these other species function primarily in courtship or in mother-daughter interactions, which suggests that the functions of stridulation and the behavioral contexts have diversified in the Heteroptera. [ABSTRACT FROM PUBLISHER]

Abstract: This paper describes the biomechanics of an unusual form of wing stridulation in katydids, termed here ‘reverse stridulation’. Male crickets and katydids produced sound to attract females by rubbing their forewings together. One of the wings bears a vein ventrally modified with teeth (a file), while the other harbours a scraper on its anal edge. The wings open and close in rhythmic cycles, but sound is usually produced during the closing phase as the scraper moves along the file. Scraper-tooth strikes create vibrations that are subsequently amplified by wing cells specialised in sound radiation. The sound produced is either resonant (pure tone) or non-resonant (broadband); these two forms vary across species, but resonant requires complex wing mechanics. Using a sensitive optical diode and high-speed video to examine wing motion, and Laser Doppler Vibrometry (LDV) to study wing resonances, I describe the mechanics of stridulation used by males of the neotropical katydid Ischnomela gracilis (Pseudophyllinae). Males sing with a pure tone at ca.15kHz and, in contrast to most Ensifera using wing stridulation, produce sound during the opening phase of the wings. The stridulatory file exhibits evident adaptations for such reverse scraper motion. LDV recordings show that the wing cells resonate sharply at ca. 15kHz. Recordings of wing motion suggest that during the opening phase, the scraper strikes nearly 15,000 teeth/s. Therefore, the song of this species is produced by resonance. The implications of such adaptations (reverse motion, file morphology, and wing resonance) are discussed. [Copyright &y& Elsevier]

Male field crickets emit pure-tone mating calls by rubbing their wings together. Acoustic radiation is produced by rapid oscillations of the wings, as the right wing (RW), bearing a file, is swept across the plectrum borne on the left wing (LW). Earlier work found the natural resonant frequency (fo) of individual wings to be different, but there is no consensus on the origin of these differences. Previous studies suggested that the frequency along the song pulse is controlled independently by each wing. It has also been argued that the stridulatory file has a variable fo and that the frequency modulation observed in most species is associated with this variability. To test these two hypotheses, a method was developed for the non-contact measurement of wing vibrations during singing in actively stridulating Gryllus bimaculatus. Using focal microinjection of the neuroactivator eserine into the cricket's brain to elicit stridulation and micro-scanning laser Doppler vibrometry, we monitored wing vibration in actively singing insects. The results show significantly lower fo in LWs compared with RWs, with the LW fo being identical to the sound carrier frequency (N=44). But during stridulation, the two wings resonate at one identical frequency, the song carrier frequency, with the LW dominating in amplitude response. These measurements also demonstrate that the stridulatory file is a constant resonator, as no variation was observed in fo along the file during Sound radiation. Our findings Show that, as they engage in stridulation, cricket wings work as coupled oscillators that together control the mechanical oscillations generating the remarkably pure species-Specific song. [ABSTRACT FROM AUTHOR]

Abstract: Crickets produce stridulated sounds by rubbing their forewings together. The calling song of the cricket species Eneoptera guyanensis Chopard, 1931 alternates two song sections, at low and high dominant frequencies, corresponding to two distinct sections of the stridulatory file. In the present study we address the complex acoustic behavior of E. guyanensis by integrating information on the peculiar morphology of the stridulatory file, the acoustic analysis of its calling song and the forewing movements during sound production. The results show that even if E. guyanensis matches the normal cricket functioning for syllable production, the stridulation involves two different closing movements, corresponding to two types of syllables, allowing the plectrum to hit alternately each differentiated section of the file. Transition syllables combine high and low frequencies and are emitted by a complete forewing closure over the whole file. The double-teeth section of the stridulatory file may be used as a multiplier for the song frequency because of the morphological multiplication due to the double teeth, but also because of an increase of wing velocity when this file section is used. According to available phylogenetic and acoustic data, this complex stridulation may have evolved in a two-step process. [Copyright &y& Elsevier]

Stridulatory sound-producing behavior is widespread across catfish families, but some are silent. To understand why, we compared spine morphology and ecotype of silent and vocal clades. We determined vocal ability of laboratory specimens during disturbance behavior. Vocal families had bony (not flexible or segmented) spines, well-developed anterior and/orposterior serrations, and statistically significantly longer spines. We compared morphology of the proximal end of the pectoral spine between vocal and silent species. For vocal taxa, microscopic rounded or bladed ridges or knobs were present on the dorsal process. Most silent species had reduced processes with exclusively smooth, convoluted, or honeycombed surfaces very similar to spine-locking surfaces, or they had novel surfaces (beaded, vacuolated, cobwebbed). Most callichthyids had ridges but many were silent during disturbance. All doradid, most auchenipterid and most mochokid species were vocal and had ridges or knobs. Within the Auchenipteridae, vocal species had spines with greater weight and serration development but not length. Silent auchenipterids had thin, brittle, distally segmented spines with few microscopic serrations on only one margin and a highly reduceddorsal process lacking any known vocal morphology. Silent auchenipterids are derived and pelagic, while all vocal genera are basal and benthopelagic. This is the first phylogenetic evidence for stridulation mechanism loss within catfishes. Phylogenetic mapping of vocal ability, spine condition, and ecotype revealed the repeated presence of silence and vocal taxa, short and long spines, and ecotype shifts within clades. The appearance and loss of vocal behavior and supporting morphologies may have facilitated diversification among catfishes [Current Zoology 56 (1): 73–89 2010]. [ABSTRACT FROM AUTHOR]

Rapid, effective communication between colony members is a key attribute that enables ants to live in dominant, fiercely protected societies. Their signals, however, may be mimicked by other insects that coexist as commensals with ants or interact with them as mutualists or social parasites. We consider the role of acoustics in ant communication and its exploitation by social parasites. Social parasitism has been studied mainly in the butterfly genus Maculinea, the final instar larvae of which are host-specific parasites of Myrmica ants, preying either on ant grubs (predatory Maculinea) or being fed by trophallaxis (cuckoo Maculinea). We found similar significant differences between the stridulations of model queen and worker ant castes in both Myrmica sabuleti and Myrmica scabrinodis to that previously reported for Myrmica schencki. However, the sounds made by queens of all three Myrmica species were indistinguishable, and among workers, stridulations did not differ significantly in two of three species-pairs tested. Sounds recorded from the predatory caterpillars and pupae of Maculinea anon had similar or closer patterns to the acoustics of their host Myrmica sabuleti than those previously reported for the cuckoo Maculinea rebel! and its host Myrmica schenck!, even though Maculinea rebel! caterpillars live more intimately with their host. We conclude that chemical mimicry enables Maculinea larvae to be accepted as colony members by worker ants, but that caterpillars and pupae of both predatory and cuckoo butterflies employ acoustical mimicry of queen ant calls to elevate their status towards the highest attainable position within their host's social hierarchy. [ABSTRACT FROM AUTHOR]

Oryctes rhinoceros (L.) (Coleoptera: Scarabaeidae: Dynastinae) causes economically important damage to ornamental and commercial coconut palm trees in the western Pacific region that could be mitigated significantly by early detection and treatment. Adults are difficult to detect visually because they attack the crowns of the trees and feed internally before mating and dispersing to new hosts. Visual inspection is nevertheless the most widely used detection method, augmented with pheromone traps. This species is an ideal candidate for acoustic detection because the adults are large, active borers that produce stridulations during courtship and mating. The stridulations have distinct, easily recognized temporal patterns. Larvae and pupae also produce stridulations. To assist in development of new detection methods, acoustic characteristics of the adult and larval stridulations have been quantified and compared with stridulations produced by larvae of other dynastids recorded in the western Pacific region. [ABSTRACT FROM AUTHOR]

The article focuses on the findings of a study concerning the sound production of Caribbean spiny lobster or Panulirus argus, as well as its role in escape during predatory attack by Octopus briareus. It mentions that Caribbean spiny lobsters produce sounds during tailflip escape attempts in response to grasp of the carapace by human divers. Researchers of the study examined defensive stridulation during nighttime encounters with Caribbean reef octopus to determine how spiny lobsters use sound production and whether it improves survival. It concludes that lobsters produce sound both during grasping attacks by octopus and after being captured.