Stridulatory Research Articles

Studies on Neotropical Phasmatodea XVI: Revision of Haplopodini Günther, 1953 (rev. stat.), with notes on the subfamily Cladomorphinae Bradley & Galil, 1977 and the descriptions of a new tribe, four new genera and nine new species(Phasmatodea: "Anareolatae": Phasmatidae: Cladomorphinae).

Studies on Neotropical Phasmatodea XVI: Revision of Haplopodini Günther, 1953 (rev. stat.), with notes on the subfamily Cladomorphinae Bradley & Galil, 1977 and the descriptions of a new tribe, four new genera and nine new species(Phasmatodea: "Anareolatae": Phasmatidae: Cladomorphinae).

The evolution of stridulatory communication in ants, revisited

The presence and use of a stridulatory organ (SO) to produce vibrational signals is highly variable and structured within the ants. The file and scraper that make up the SO are specialized morphological features not used for functions other than stridulation (a vibratory signal production mechanism) and not found in non-stridulating species. It has been hypothesized and generally accepted that the stridulatory organ first evolved to alert nest mates of burial and need for rescue. Based on this premise, arboreal species are expected to exhibit a reduction of use of vibrational signals when compared to terrestrial species. Using ancestral state reconstruction, we have mapped the presence of the SO on a molecular phylogeny of the ants and found support for the hypothesis that the SO evolved multiple times in the ants. We quantitatively tested the hypothesis that stridulation evolved initially to signal burial/rescue by comparing the presence of the SO to general foraging and nesting preferences for 76 genera evenly spread throughout the currently accepted ant phylogeny. We found that a greater proportion of genera that are considered primarily arboreal possess a SO, as opposed to the ground nesting genera, and none of the five entirely subterranean genera included in this study possess a SO. We therefore reject the previous hypothesis regarding burial/rescue signaling.

Description of the stridulatory apparatus of the Far Eastern bark beetles Polygraphus proximus Blandford, 1894 and P. jezoensis Niisima, 1909 (Coleoptera, Curculionidae: Scolytinae)

The stridulatory organ structure in two Far Eastern bark beetles, Polygraphus proximus and P. jezoensis, is described. The elytro-tergal type of the stridulatory apparatus is found in P. jezoensis. The structure involved in acoustic communication of P. jezoensis is present only in males. The plectrum of P. proximus males is re-described. Similarly to that in P. jezoensis, it is formed by two tubercles at the distal margin of tergite VII. An additional type of stridulatory organ used for the producing of precopulatory courtship signals is described for males of P. proximus. In this type of stridulatory organ, transverse ridges on the costal margin of the elytron act as pars stridens, and the hind tibia, as the plectrum.

Discovery of the first telemid spider (Araneae, Telemidae) from South America, and the first member of the family bearing a stridulatory organ.

The genus Kinku n. gen. is established for the first telemid spider found in South America. The new species, Kinku turumanya n. sp. is characterized by the unique conformation of the male palp and the presence of an abdominal anterioventral stridulatory organ.

Mating Behavior of Letana inflata, a Duetting Phaneropterine Bush-Cricket Species with Unusual Male Genitalic Organs (Orthoptera: Tettigonioidea: Phaneropteridae)

In the mate recognition system of bush-crickets (Tettigonioidea) two character complexes are most important: acoustic communication for long-distance attraction and genital fitting during the actual mating process. Here we describe these both components for Letana inflata, a species of the subfamily Phaneropterinae in which the females typically do not approach the singing males phonotactically but respond with their own acoustical signals to the male song. In this duet males and females use extremely short signals. As a calling song the males produce mainly one single loud impulse of less than one millisecond duration, which is answered by the female after about half a second again only with one or up to three short loud impulses. Male and female signals have similar carrier frequencies, although their stridulatory organs are not homologous and possess different forms. When mating, males and females engage in an unusually prolonged copulation which lasts more than three hours. Most phaneropterine species studied before mate for less than four minutes. The long duration may be related to the presence of a titillator (phallic sclerite), not present in most phaneropterines studied so far, and a very unusually shaped male subgenital plate which allows the male a stable hold of the female ovipositor. Already 30–60 min after beginning of the copulation the males were found to carry the sperm-containing ampulla inside their body with the tip of the ampulla being in contact with the female genital opening. The mating behavior is discussed especially in comparison with the other tettigonioid species with prolonged copulation.

The Pied Piper: A Parasitic Beetle's Melodies Modulate Ant Behaviours.

Ants use various communication channels to regulate their social organisation. The main channel that drives almost all the ants’ activities and behaviours is the chemical one, but it is long acknowledged that the acoustic channel also plays an important role. However, very little is known regarding exploitation of the acoustical channel by myrmecophile parasites to infiltrate the ant society. Among social parasites, the ant nest beetles (Paussus) are obligate myrmecophiles able to move throughout the colony at will and prey on the ants, surprisingly never eliciting aggression from the colonies. It has been recently postulated that stridulatory organs in Paussus might be evolved as an acoustic mechanism to interact with ants. Here, we survey the role of acoustic signals employed in the Paussus beetle-Pheidole ant system. Ants parasitised by Paussus beetles produce caste-specific stridulations. We found that Paussus can “speak” three different “languages”, each similar to sounds produced by different ant castes (workers, soldiers, queen). Playback experiments were used to test how host ants respond to the sounds emitted by Paussus. Our data suggest that, by mimicking the stridulations of the queen, Paussus is able to dupe the workers of its host and to be treated as royalty. This is the first report of acoustic mimicry in a beetle parasite of ants.

A new species of the genus Meiyingia Holzchuh, 2010 (Coleoptera, Cerambycidae, Cerambycinae) from China.

The genus Meiyingia Holzchuh, 2010 presently consists of only one species, Meiyingia paradoxa Holzchuh, 2010 from Henan and Shaanxi, China. The genus is characterized by following characters: Head concave between antennal tubercles; clypeus narrow; frons flattened. Eyes small, finely faceted, divided with two lobes widely separated. Antennae slender; those of males longer than the body, with spines at basal antennomeres; third antennomere longest, eleventh antennomere shorter than previous ones. Pronotum slightly longer than broad. Stridulatory organ without median groove. Elytra soft, membranous and narrowed posteriorly with apex rounded; disc flattened. Legs very short, femora gradually widened, tibiae long; first hind tarsal segment longer than following two combined. Procoxal cavity widely open. Prosternal process very short, narrow and deep. Metacoxal cavity open to mesepimeron. Second to fourth sternites pressed in the middle, sternites remarkably long and densely hairy medially. The first four sternites laterally with greater dent.

Morphology of the stridulatory organs of Iberian myrmicine ants (Hymenoptera: Formicidae)

The importance of chemical communication in ants has been widely reported, but acoustic communication also has a significant role in those subfamilies that show this behaviour. In this study, we expand the knowledge about stridulatory organs of the subfamily Myrmicinae (Hymenoptera: Formicidae) with the first description of the stridulatory organs of five species (Aphaenogaster striativentris, Goniomma blanci, G. hispanicum, Oxyopomyrmex salulcyi and Pheidole pallidula). Subsequently, we made a morphometric study of 16 species to make comparisons of their stridulatory organs. Scanning electron microscope (SEM) photographs were taken for the morphological study, and the head and dimensions of the pars stridens, together with measurements of the striae, were used for the morphometric analysis. The five myrmicines studied show typical stridulatory organs for Formicidae. We also add two genera (Goniomma and Oxyopomyrmex) to the list of genera that are known to have stridulatory organs. The morphometric study shows a positive correlation between the body size and the size of the pars stridens and between the length and width of the pars stridens. However, a relation between the size of the stridulatory organs and the size of the striae of the pars stridens was not detected. Stridulatory organs have been shown to have significant interspecific differences in size.

How do "mute" cicadas produce their calling songs?

Insects have evolved a variety of structures and mechanisms to produce sounds, which are used for communication both within and between species. Among acoustic insects, cicada males are particularly known for their loud and diverse sounds which function importantly in communication. The main method of sound production in cicadas is the tymbal mechanism, and a relative small number of cicada species possess both tymbal and stridulatory organs. However, cicadas of the genus Karenia do not have any specialized sound-producing structures, so they are referred to as “mute”. This denomination is quite misleading, as they indeed produce sounds. Here, we investigate the sound-producing mechanism and acoustic communication of the “mute” cicada, Karenia caelatata, and discover a new sound-production mechanism for cicadas: i.e., K. caelatata produces impact sounds by banging the forewing costa against the operculum. The temporal, frequency and amplitude characteristics of the impact sounds are described. Morphological studies and reflectance-based analyses reveal that the structures involved in sound production of K. caelatata (i.e., forewing, operculum, cruciform elevation, and wing-holding groove on scutellum) are all morphologically modified. Acoustic playback experiments and behavioral observations suggest that the impact sounds of K. caelatata are used in intraspecific communication and function as calling songs. The new sound-production mechanism expands our knowledge on the diversity of acoustic signaling behavior in cicadas and further underscores the need for more bioacoustic studies on cicadas which lack tymbal mechanism.

Stridulatory sound-production and its function in females of the cicada Subpsaltria yangi.

Acoustic behavior plays a crucial role in many aspects of cicada biology, such as reproduction and intrasexual competition. Although female sound production has been reported in some cicada species, acoustic behavior of female cicadas has received little attention. In cicada Subpsaltria yangi, the females possess a pair of unusually well-developed stridulatory organs. Here, sound production and its function in females of this remarkable cicada species were investigated. We revealed that the females could produce sounds by stridulatory mechanism during pair formation, and the sounds were able to elicit both acoustic and phonotactic responses from males. In addition, the forewings would strike the body during performing stridulatory sound-producing movements, which generated impact sounds. Acoustic playback experiments indicated that the impact sounds played no role in the behavioral context of pair formation. This study provides the first experimental evidence that females of a cicada species can generate sounds by stridulatory mechanism. We anticipate that our results will promote acoustic studies on females of other cicada species which also possess stridulatory system.

Intraspecific sexual mimicry for finding females in a cicada: males produce ‘female sounds’ to gain reproductive benefit

In insects various ways to produce sounds have evolved for communication both within and between species. Cicada males are particularly known for their loud and diverse songs which are produced by tymbal organs. Females of some cicada species can produce sounds by wing flicking in response to male calls. The cicada species Subpsaltria yangi is unusual in that, besides the tymbal organs of males, it has well-developed stridulatory organs that are found in both sexes. Here, we investigated sound production and mating behaviour of this cicada species. We show that, in the context of pair formation, females produced sound signals by stridulation in response to advertisement signals produced by males with tymbal organs. We also found that the sounds produced by male cicadas with stridulatory organs were extremely similar in acoustic structure to those of females, which indicates that males mimic the signals produced by females during pair formation. Acoustic playback experiments suggested that, by producing female-like sound signals, a male could deceive a receptive female into treating him as a rival female, which makes the male more effective in eliciting acoustic responses from the receptive female. Therefore, the males could gain reproductive benefit by mimicking female sound signals, since they rely primarily on females' acoustic responses to find females. Our study provides the first experimental evidence for sound production by a stridulatory mechanism in cicadas, and a novel case of intraspecific sexual mimicry based on acoustic similarity. • We investigated the acoustic behaviour of the cicada Subpsaltria yangi . • Males can produce sounds by tymbal and stridulatory mechanisms. • Females are able to produce sounds by a stridulatory mechanism. • Males mimic sound signals of females to gain reproductive benefit. • We provide a novel case of intraspecific sexual mimicry based on acoustic similarity.

Stridulation and Courtship Behaviour of Four Endemic Pill-Millipedes, Arthrosphaera spp. (Sphaerotheriida: Arthrosphaeridae) of the Western Ghats of India

Mating behaviour of four species of pill-millipedes under genus Arthrosphaera Pocock (Arthrosphaera dalyi Pocock and Arthrosphaera disticta Pocock, Arthrosphaera fumosa Pocock and Arthrosphaera magna Attems) endemic to the Western Ghats of Southern India was analyzed in mesocosms. Stridulation is a classical communication signal in males as well as females for mate selection. Conglobation (or volvation) is a mechanism of defence to protect from disturbance or avoid predation. If male touches female or vice versa they conglobate. To avoid disparity among individuals of the same species, volvating pill-millipedes evolved stridulation behaviour for communication. The male broadcasts appropriate signal to female through stridulation to advertise its interest in mating. The females test the male’s fitness by conglobation and suitable male uncoils the partner through stridulation signals. Male with its pygidium successfully uncoils the female and attains suitable orientation for courtship. Male pairs with female ventro–ventro contact in opposite direction to deposit sperm into the vulva of female. The duration of mating varies from species to species and usually a lapse from 3 to 30 min. Vibration generated by stridulation is species-specific and its perception mechanism in pill-millipedes is yet to be clearly understood. Present study emphasized the structure of stridulatory organs, mechanism of stridulation and pattern of mating behaviour in four species of pill-millipedes.

Ecology, acoustics and chromosomes of the East African genus Afroanthracites Hemp & Ingrisch (Orthoptera, Tettigoniidae, Conocephalinae, Agraeciini) with the description of new species

The flightless Agraeciini genus Afroanthracites, a genus restricted to East Africa, is reviewed and two new species are described. Exemplary for the genus Afroanthracites, the ecological niche of Afroanthracites montium from Mt Kilimanjaro is defined. A. montium occupies habitats in humid and perhumid conditions and thus shows a broad altitudinal range (1250–2700 m). Concerning the acoustic communication, it is remarkable that within the micropterous genus a trend to low carrier frequencies is observed combined with the evolution of larger stridulatory organs (mirror; resonating part of tegmen). This trend starts with species using the same ultrasonic frequencies as a brachypterous out-group and ends with species presenting clearly audible songs. Cytogenetic data are given for five Afroanthracites and one Afroagraecia species. Differences in chromosome numbers Afroanthracites 2n = 29 and Afroagraecia 2n = 27 as well as a number of major rDNA clusters (one and two, respectively) are probably useful markers to separate both genera. It is discussed whether the African species evolved from a species with a presumably derived karyotype (e.g. 27 or 29 chromosomes) or if the proposed reduction of chromosome number occurred independently in Africa, Asia and Australia. The data set suggests that the African Agraeciini is of monophyletic origin, with a common ancestor of Afroagraecia and Afroanthracites in Africa. The Afroanthracites species can be divided into three groups on base of their morphology and colour pattern. Species of adjacent areas are morphologically sister groups. The most derived forms as seen in their morphology and acoustics are found in the West Usambara Mountains, part of the geologically old Eastern Arc Mountains.

Form, function and evolutionary significance of stridulatory organs in ant nest beetles (Coleoptera: Carabidae: Paussini)

Stridulatory organs in the myrmecophilous carabid beetle tribe Paussini have long been recognized and used as a defining character of some genera and higher level taxa, however their morphology has only roughly been described. Here, we describe the fine morphology of Paussini stridulatory organs using scanning electron (SeM) and focused ion beam (FIB) microscopy. Within this tribe, there are three types of stridulatory organs, each with different positions of the scraper (plectrum) and file (pars stridens). type I (abdomen-femur type) is located on the abdomen (scraper) and metafemur (file) in the subtribe Paussina (sensu Geiselhardt et al., 2007, Naturwissenschaften 94: 871-894). type II (thorax-femur type) and ype III (femur-thorax type) are located on the mesothorax and mesofemur in two different genera of the subtribe Platyrhopalina, however in Euplatyrhopalus the scraper is located on the mesothorax and the file is located on the mesofemur (t ype II), whereas in the genus Platyrhopalopsis the structures are reversed in that the file is located on the mesothorax and the scaper is located on the mesofemur (t ype III). the independent evolution of three types of stridula ­ tory organs in three lineages of Paussini suggests that acoustical communication has played an important role in the evolution of ant nest beetles. While the roles of stridulation in this group remain speculative, we verified that all three types of stridulatory organs are present in both sexes and are similar to stridulatory organs known in their host ants which also use stridulation as a method of com­ munication. We discuss the possibility that the beetles' stridulation could (1) facilitate their exploitation of ant colonies, and (2) be involved in mate recognition and courtship.

Bioacoustics of Trachymyrmex fuscus, Trachymyrmex tucumanus, and Atta sexdens rubropilosa (Hymenoptera: Formicidae)

The capability to produce species-specific sounds is common among ants. Ants of the genus Trachymyrmex occur in an intermediate phylogenetic position within the Attini tribe, between the leafcutters, such as Atta sexdens rubropilosa, and more basal species. The study of stridulations would provide important cues on the evolution of the tribe’s diverse biological aspects. Therefore, in the present study, we described the stridulation signals produced by Trachymyrmex fuscus, Trachymyrmex tucumanus, and A. sexdens rubropilosa workers. Ant workers were recorded, and their stridulatory organs were measured. The following parameters were analyzed: chirp length [ms], inter-chirp (pause) [ms], cycle (chirp + inter-chirp) [ms], cycle repetition rate [Hz], and the peak frequency [Hz], as well as the number of ridges on the pars stridens. During the inter-chirp, there is no measurable signal for A. sexdens rubropilosa, whereas for Trachymyrmex fuscus and Trachymyrmex tucumanus, a low intensity signal was detected. In other words, the plectrum and the pars stridens of A. sexdens rubropilosa have no contact during the lowering of the gaster. Principal component analysis, to which mainly the duration of chirps contributed, showed that stridulation is an efficient tool to differentiate ant species at least in the case of the Attini tribe.

First evidence of acoustic communication in the pear psyllid Cacopsylla pyri L. (Hemiptera: Psyllidae)

A number of species of the family Psyllidae, commonly called jumping plant lice, are economically important as vectors of pathogenic phytoplasmas in fruit crops. Pear psyllids of the species Cacopsylla pyri (L. 1758) (Psyllidae) are the most damaging pest of pear trees in Europe. These phloem feeding insects transmit pear decline, a disease caused by the phytopathogenic bacterium Candidatus Phytoplasma pyri. Knowledge of the signals used for intraspecific communication, especially during mating behavior, is essential to design ecological control strategies against this vector insect. Here, we report the first recordings of acoustic signals emitted by male and female C. pyri. We also observed the establishment of an acoustic duet between an interacting couple prior to mating. Furthermore, we found potentially sound producing stridulatory organs in male and female individuals of C. pyri. The acoustic signals recorded are described and presented. Possible stridulatory organs are depicted as scanning electron microscopy pictures. The implications of these findings for potential applications in pest control are discussed.

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

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

Taxonomic revision ofHemirrhagus Simon, 1903 (Araneae: Theraphosidae, Theraphosinae), with description of five new species from Mexico

The theraphosine genus Hemirrhagus Simon 1903 is revised based on the examination of the type specimens and additional material collected in Mexico. Eight species were redescribed and illustrated. The males of Hemirrhagus ocellatus, Hemirrhagus papalotl, and Hemirrhagus stygius, formerly unknown, are described for the first time. Five new species were recognized and are newly described and illustrated. Hence, Hemirrhagus comprises 21 valid species, all endemic to Mexico. All species are keyed and mapped. New taxonomic features are included in the descriptions and different types of stridulatory organs are described for the first time for the genus. It is reported for the first time that Hemirrhagus is the only known Theraphosinae that lays fixed egg-sacs. Hemirrhagus embolulatus sp. nov. is described as the only known Hemirrhagus that possesses embolus keels present in other Theraphosinae genera. Information on species habitat and reproduction are included. © 2014 The Linnean Society of London

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

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

Description of a new genus and new species of Sesarmidae (Decapoda: Brachyura) from the Farasan Islands, Saudi Arabia, Red Sea

A new genus, Eneosesarma, is created for a new species of sesarmid crab, E. azizi, from Saso Island, Farasan Archipelago, Saudi Arabia. The new species shows close affinities with species of the sesarmid genera Sesarmoides Serene and Soh, 1970 and Karstarma Davie and Ng, 2007, but differs from these in regard to carapace shape, morphology of male G1, and absence of stridulatory organ.