Search

Neotropical butterflies of the genus Hamadryas, noted by the emission of sound, spend much time perching on trees and are believed to be cryptically patterned and colored with respect to tree trunks and branches they use as perching sites, but the subject had not been studied previously. This paper describes spatial distribution, territoriality and sound production in five species, under natural conditions: Hamadryas amphinome (Lucas, 1853), H. februa (Godart, 1824), H. feronia (Fruhstorfer, 1916), H. glauconome (Bates, 1864) and H. guatemalena (Bates, 1864). Tree characteristics and use by butterflies were recorded under natural conditions in open habitats (grassland thinly covered with trees) in Costa Rica and Panama, avoiding the problems that affected previous natural selection studies in Biston betularia (the "industrial melanism" moth). Males perched on the trees and used them as courting territories. The butterflies perched more often on some individual trees, and did not use others. The general tree bark ("background") color tended to match wing coloration, while presence of food, position of trees along flight routes, tree size, bark texture, and lichen cover were not associated with the frequency of perching on the trees. Most individuals that perched in the study sites were males. Species differed in perching height and populations of H. februa perched at the same heights in both countries; H. feronia moves to higher perches near day's end. The relative use of branches and trunks is not related to the time of day but reflects the typical perching height of each species. The northern side of trees is less used and cardinal side distribution is independent of time of day. Perches exposed to direct sunlight are less used in hot days. All species perch with the head downwards. Perching males frequently fly towards other Hamadryas as well as towards tethered cardboard models. Trees with experimentally removed males were taken by newcomers 32 times more often than trees with resident males. Each marked H. feronia male was seen perching on 1-4 trees daily, without difference between seasons, and each tree used had a minimum daily mean of 1.5 perching butterflies. Most H. feronia interactions occur from 13:00 through 15:00 hours and are more frequent in the rainy season. At night males share perches. Sound emission was studied by using non-destructive experimental methods (N=858) and with a scanning electron microscope. Both sexes emit sound and the sound apparatus, located in the forewing, is percussive, not stridulatory. At the end of the upward wingstroke, the wings are clapped and modified r-m1-2 veins meet at a speed of approximately 1420 mm/s, producing the characteristic clicks. Wingbeat frequency of free-flying individuals is 20-29 Hz. There is some wing deformation during movement. Clicks last a mean of 1.38 ms with mean intervals of 43.74 ms and the component frequencies concentrate around 2.4 kHz, matching Hamadryas hearing capacity and being appropriate for the acoustic conditions of habitat. The swollen Sc vein is present exclusively in Hamadryas; has a serpentine structure inside and probably acts as resonance box. Growth of the sound apparatus may be checked by its effect on flight capacity, physiological costs and ecological reasons. All Hamadryas have a membrane, shaped as an elongated cupola, in the costal cell, that acts as ear. A second and smaller ear has four chambers and may detect predatory bats when the insects are perching at night. Field observations showed that Hamadryas spp. emit audible clicks when approached by potential predators, to defend territories from other Hamadryas and in at least one species also during courtship. Severe wing damage, common in wild Hamadryas almost never affects the section with the sound mechanism. A review of the literature shows that more than 50 species of lepidopterans (11 families) emit sound audible to humans and suggests that sound mechanisms evolved several times. In general, lepidopteran sound is used basically as a warning to predators and for intraspecific communication.Las Hamadryas son mariposas neotropicales que emiten sonido y pasan mucho tiempo posadas en árboles, donde son crípticas. Se estudió cinco especies en Costa Rica y Panama. Cada especie tiene una altura característica para posarse. Se posaron menos del lado sur de los árboles y evitaron las partes soleadas en días calurosos. Los machos dejaron su percha para volar hacia otras Hamadryas y hacia "mariposas" de cartón. Cuando se retiró los machos de los árboles éstos fueron tomados con mucha mayor frecuencia por otros machos. La mayoría de las interacciones aéreas de H. feronia se dieron entre las 13:00 y las 15:00 h y fueron más frecuentes en la estación lluviosa. De noche, los machos compartían los árboles. El sonido característico del grupo es producido por venas modificadas en las alas delanteras.

Mixed courtship vibro-acoustical signals of Conocephalus fuscus (Fabr.) (= discolor Thunb.) and C. dorsalis (Latr.) males have been registered for the first time. Oscillograms are presented. [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]

Factors affecting mating behaviour in the bug Triatoma infestans were quantitatively studied in the laboratory. Experimental conditions were established so that the probability of copulation increased with the time elapsed since the first adult meal. Copulatory attempts by males did not vary as a function of time, but rejections by females became significantly less frequent with the post feeding time. Non-receptive females displayed four types of rejection behaviour, i.e. flattening, stridulation, evasion and abdominal movements. The occurrence of stridulation performed by females in a sexual context was observed in a regular fashion and was quantified for the first time in this species.

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]

Vibrations and sounds, collectively called vibroacoustics, play significant roles in intracolony communication in termites, social wasps, ants, and social bees. Modalities of vibroacoustic signal production include stridulation, gross body movements, wing movements, high-frequency muscle contractions without wing movements, and scraping mandibles or tapping body parts on resonant substrates. Vibroacoustic signals are perceived primarily via Johnston's organs in the antennae and subgenual organs in the legs. Substrate vibrations predominate as vibroacoustic modalities, with only honey bees having been shown to be able to hear airborne sound. Vibroacoustic messages include alarm, recruitment, colony activation, larval provisioning cues, and food resource assessment. This review describes the modalities and their behavioral contexts rather than electrophysiological aspects, therefore placing emphasis on the adaptive roles of vibroacoustic communication. Although much vibroacoustics research has been done, numerous opportunities exist for continuations and new directions in vibroacoustics research. [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]

Abstract: Due to the mostly qualitative, scarce and scattered available data, it is still debated if stridulation patterns and morphology of stridulatory organ are species-specific traits in velvet ants (Hymenoptera: Mutillidae). Here, we test such an hypothesis, analysing the stridulation patterns and the associated morphology in females of six species spanning five genera and three subfamilies. In all the species, sound is produced by rubbing together a morphologically well-defined file composed of parallel ridges (on metasomal tergite III) and a weakly defined scraper (on tergite II). In all species, the resulting sound is made of sequences of pulse-trains organized in two subunits (disyllabic chirps) characterized by pulses with opposite phase. We found important differences among species in the morphology of the file concerning its size, the inter-ridges distance, the ridge thickness and the density of ridges. We also found some differences in distress-call patterns, mostly concerning the duration of syllables and the number of pulses/ms. Tergite III size seems to have some effects on file morphology and limited effect on sound patterns, though a larger sample size is required to confirm these results. Classification and Regression Tree analyses revealed that five morphological and five acoustical variables had, overall, a role in assigning correctly most individuals to their species. Overall, taxonomic relatedness among species seemed to weakly account for inter-specific morphological similarity and not to account for acoustical similarity, suggesting that ecological factors may have been important in shaping species-specific stridulation in velvet ants. [Copyright &y& Elsevier]

Abstract: The taxon Hetrodinae includes species of highly diverse morphology. Here, the acoustic communication system of six species is investigated. Males of Acanthoplus discoidales, Acanthoplus longipes, Acanthoproctus cervinus, Acanthoproctus diadematus, Enyaliopsis sp. and Spalacomimus liberiana produce long lasting calling songs to attract females. The frequency spectra of these songs are rather similar, while the temporal pattern differs largely. A continuous song, which is a train of verses, is produced by two species, while the other investigated Hetrodinae produce a song with periodical interruptions, which separates the verses into groups. The songs contain species specific numbers of impulses per verse or of verses per group. The stridulatory files have a different number of stridulatory teeth. Investigations of the neuronal system showed similarities in the central projections of the auditory fibres, while the number of sensory cells varies between the species. The greatest sensitivity of the hearing range is between 4 and 12kHz, with a broader range in Acanthoproctus. In conclusion, the auditory communication system of the Hetrodinae species is similar to that of other Tettigoniids and exhibits species specific characters. [Copyright &y& Elsevier]

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]

The neural mechanisms underlying cricket singing behavior have been the focus of several studies, but the central pattern generator (CPG) for singing has not been localized conclusively. To test if the abdominal ganglia contribute to the singing motor pattern and to analyze if parts of the singing CPG are located in these ganglia, we systematically truncated the abdominal nerve cord of fictively singing crickets while recording the singing motor pattern from a front-wing nerve. Severing the connectives anywhere between terminal ganglion and abdominal ganglion A3 did not preclude singing, although the motor pattern became more variable and failure-prone as more ganglia were disconnected. Singing terminated immediately and permanently after transecting the connectives between the metathoracic ganglion complex and the first unfused abdominal ganglion A3. The contribution of abdominal ganglia for singing pattern generation was confirmed by intracellular interneuron recordings and current injections. During fictive singing, an ascending interneuron with its soma and dendrite in A3 depolarized rhythmically. It spiked 10 ms before the wing-opener activity and hyperpolarized in phase with the wing-closer activity. Depolarizing current injection elicited rhythmic membrane potential oscillations and spike bursts that elicited additional syllables and reliably reset the ongoing chirp rhythm. Our results disclose that the abdominal ganglion A3 is directly involved in generating the singing motor pattern, whereas the more posterior ganglia seem to provide only stabilizing feedback to the CPG circuit. Localizing the singing CPG in the anterior abdominal neuromeres now allows analyzing its circuitry at the level of identified interneurons in subsequent studies. [ABSTRACT FROM AUTHOR]

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]

The article discusses results of a study that examines the Baltic amber, Eohelea petrunkevitchi's wing structures for modes of material properties, fabrication and biological functions and the effective ecological environment in which these midges lived. The study material and methods are discussed, including specimens used from the Harvard Museum of Comparative Zoology and Mount Holyoke College. The study showed that the wing structure differs in form between species, Eohelea petrunkevitchi and Eohelea sinuosa.

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.

Psyllids perform duetting via vibrational signals between genders that are important in pre-copulation species specific recognition. To date, vibrational behavior has been recorded in more than 100 species of psyllid, which is still only a small fraction of the ∼4000 described species. In this overview, we categorize the duet behavior into (1) reciprocal duets, (2) engaged duets, (3) three-way duets and (4) loose duets. In species with notable signal differences between genders, typically the male possesses a longer, more complex signal, which is emitted at a higher frequency compared to those of the females. Vibrational signals exhibit species specific characteristics that are taxonomically informative in some cases. Despite only a limited number of vibrational communication studies incorporating phylogenetic analyses, these reveal that signals can have reliable systematic information, but also that evolutionary and/or environmental factors may influence signal characteristics in ways that confound phylogenetic signal. Other possible strategies employed in mate finding in psyllids are chemical and visual signals. The most likely mechanism of vibrational signal production in psyllids involves stridulation between forewing and thorax. In some applied approaches, methods exploiting vibrational signals to disrupt mating may be effective to control psyllid pests in the field. • Signals of 107 psyllid species among 47 genera of six families have been recorded. • Four duet type: reciprocal duets, engaged duets, three-way duets and loose duets. • Multi-modal signaling systems in psyllid mating behavior. • Application of vibrational characteristics in systematics is valuable. • Pest control by vibrational signals can be effective. [ABSTRACT FROM AUTHOR]

Male crickets produce stridulatory songs using engaged tegmina (forewings): a plectrum on the left sweeps along a tooth row on the right. During stridulation, the plectrum moves across the teeth and vibrations are amplified by the surrounding cells and veins, resonating at the frequency of tooth impacts. The advance of the plectrum on the file is controlled by an escapement mechanism so that passing each single tooth generates one wave of a highly tonal signul. Both tegmina must oscillate in phase to avoid destructive interference. But as each plectrum-tooth contact begins, the right and left tegmina react in opposite oscillatory directions. A mechanical phase shifter is part of the left tegmen and compensates to achieve wing oscillation synchrony. We use a new technique to simulate plectrum-on-file interations: in combination with Iaser vibrometry, this technique assessed plectrum mechanics in the cricket Gryllus bimaculatus. Using an excised teneral file, shaped like a partial gear and moved by a motor, and a microscan Doppler laser vibrometer, plectrum arid left-tegmen mechanics were explored. The results show that plectrum and harp oscillate with a phase difference of ca. 156deg., a shift rather than a complete phase inversion (180deg.). This phase shift occurs at the site of a large wing vein (possibly A3). Plectrum and harp vibrate with similar fundamental frequency, therefore, plectrum torsion resonant frequency is important for maintaining vibration coherence. The mechanical aspects involved In this partial phase inversion are discussed with respect to the escapement mechanism. The plectrum mechanics and its implications in katydid stridulation are also considered. [ABSTRACT FROM AUTHOR]

Information sent by multimodal communication (i.e. signals in multiple sensory modalities) may be redundant (‘backup’ signals) or may vary in content with each mode (‘multiple messages’). Males of the brush-legged wolf spider, Schizocosa ocreata (Hentz) (Araneae: Lycosidae), use complex multimodal (visual and seismic) courtship signals. The visual component has previously been shown to be a condition-dependent signal used by females in mate choice. Here, we examine female choice based on isolated seismic signals to identify which aspects females use to evaluate males, and to determine whether visual and seismic signals are redundant. Females showed receptivity when exposed to the seismic component of male courtship alone. The attributes of seismic signals best predicting female receptivity were peak amplitude, peak frequency and maximum frequency of percussive strikes and stridulation pulse duration. Moreover, two behavioural attributes associated with seismic signals, cheliceral strike rate and double-tap rate, were also good predictors of receptivity. Males eliciting female receptivity were in better condition, and attributes of seismic communication were correlated with male size and mass, suggesting the possibility of information about male quality in seismic communication. Trait correlations also revealed overlap in information contained within visual and seismic channels. Given this overlap, we conclude that seismic and visual signals are largely redundant and may serve as backup signals but might also convey information about different male attributes. The use of redundant signalling would be adaptive in S. ocreata because this species inhabits structurally complex forest leaf litter environments where signals can be attenuated rapidly. [Copyright &y& Elsevier]

The calling song of an undescribed Meconematinae katydid (Tettigoniidae) from South America consists of trains of short, separated pure-tone sound pulses at 129 kHz (the highest calling note produced by an Arthropod). Paradoxically, these extremely high-frequency sound waves are produced by a low-velocity movement of the stridulatory forewings. Sound production during a wing stroke is pulsed, but the wings do not pause in their closing, requiring that the scraper, in its travel along the file, must do so to create the pulses. We hypothesize that during scraper pauses, the cuticle behind the scraper is bent by the ongoing relative displacement of the wings, storing deformation energy. When the scraper slips free it unbends while being carried along the file and its deformation energy contributes to a more powerful, higher-rate, one-tooth one-wave sound pulse, lasting no more than a few waves at 129 000 Hz. Some other katydid species make pure-tone ultrasonic pulses. Wing velocities and carriers among these pure-tone species fall into two groups: (1) species with ultrasonic carriers below 40 kHz that have higher calling frequencies correlated with higher wing-closing velocities and higher tooth densities: for these katydids the relationship between average tooth strike rate and song frequency approaches 1:1, as in cricket escapement mechanisms; (2) a group of species with ultrasonic carriers above 40 kHz (that includes the Meconematinae): for these katydids closing wing velocities are dramatically lower and they make short trains of pulses, with intervening periods of silence greater than the duration of the pulses they separate. This signal form may be the signature of scraper-stored elastic energy. [ABSTRACT FROM AUTHOR]

Copyright of Brazilian Journal of Biology is the property of Instituto Internacional de Ecologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)