@article {58434, title = {Gryllacrididae (Orthoptera: Ensifera) in southern Africa}, journal = {Journal of Orthoptera Research}, volume = {27}, year = {2018}, pages = {183-186}, chapter = {183}, abstract = {

Although Gryllacrididae are a largely southern hemisphere insect family, they are relatively poorly represented in southern Africa, with three genera (Ametroides Karny, 1928, Glomeremus Karny, 1937, and Stictogryllacris Karny, 1937) and ten species and subspecies recorded from the region. All Ametroides and Glomeremus species are wingless while those of Stictogryllacris are long-winged. All species are arboreal and nocturnal, returning by day to characteristically silk-spun shelters between leaves. Here, we present a diagnosis, key to genera, and high-quality images to assist in identification of Gryllacrididae. By compiling all published information in one place, we hope to facilitate future researchers to investigate this poorly known group.

}, keywords = {aptery, diagnosis, genera, macroptery, silk production, Stenopelmatoidea, taxonomic key}, url = {10.3897/jor.27.29645}, author = {Clarke Scholtz and Corinna S. Bazelet and Hennie de Klerk} } @article {58027, title = {Diversity of acoustic tracheal system and its role for directional hearing in crickets}, year = {2013}, abstract = {

Background: Sound localization in small insects can be a challenging task due to physical constraints in deriving sufficiently large interaural intensity differences (IIDs) between both ears. In crickets, sound source localization is achieved by a complex type of pressure difference receiver consisting of four potential sound inputs. Sound acts on the external side of two tympana but additionally reaches the internal tympanal surface via two external sound entrances. Conduction of internal sound is realized by the anatomical arrangement of connecting trachea. A key structure is a trachea coupling both ears which is characterized by an enlarged part in its midline (i.e., the acoustic vesicle) accompanied with a thin membrane (septum). This facilitates directional sensitivity despite an unfavorable relationship between wavelength of sound and body size. Here we studied the morphological differences of the acoustic tracheal system in 40 cricket species (Gryllidae, Mogoplistidae) and species of outgroup taxa (Gryllotalpidae, Rhaphidophoridae, Gryllacrididae) of the suborder Ensifera comprising hearing and non hearing species.

Results: We found a surprisingly high variation of acoustic tracheal systems and almost all investigated species using intraspecific acoustic communication were characterized by an acoustic vesicle associated with a medial septum. The relative size of the acoustic vesicle - a structure most crucial for deriving high IIDs - implies an important role for sound localization. Most remarkable in this respect was the size difference of the acoustic vesicle between species; those with a more unfavorable ratio of body size to sound wavelength tend to exhibit a larger acoustic vesicle. On the other hand, secondary loss of acoustic signaling was nearly exclusively associated with the absence of both acoustic vesicle and septum.

Conclusion: The high diversity of acoustic tracheal morphology observed between species might reflect different steps in the evolution of the pressure difference receiver; with a precursor structure already present in ancestral non-hearing species. In addition, morphological transitions of the acoustic vesicle suggest a possible adaptive role for the generation of binaural directional cues.

}, keywords = {Acoustic tracheal system, cricket, directional hearing, Interaural intensity difference (IID), Pressure difference receiver, Sound localization}, doi = {10.1186/1742-9994-10-61}, url = {http://frontiersinzoology.biomedcentral.com/articles/10.1186/1742-9994-10-61}, author = {Schmidt, Arne KD and R{\"o}mer, Heiner} } @article {57665, title = {Mechanical filtering for narrow-band hearing in the weta}, year = {2011}, abstract = {

This paper constitutes a major attempt to associate tympanic deflections with the mechanoreceptor organ location in an acoustic insect. The New Zealand tree weta (Hemideina thoracica) has tympanal ears located on each of the prothoracic tibiae. The tympana exhibit a sclerotized oval plate, membranous processes bulging out from the tibial cuticle and many loosely suspended ripples. We used microscanning laser Doppler vibrometry to determine how such a tympanal membrane vibrates in response to sound and whether the sclerotized region plays a role in hearing. The tympanum displays a single resonance at the calling frequency of the male, an unusual example of an insect tympana acting as a narrow bandpass filter. Both tympana resonate in phase with the stimulus and with each other. Histological sections show that the tympanal area is divided into two distinct regions, as in other ensiferans. An oval plate lies in the middle of a thickened region and is surrounded by a transparent and uniformly thin region. It is hinged dorsally to the tympanal rim and thus resembles the model of a \‘hinged flap\’. The thickened region appears to act as a damping mass on the oscillation of the thin region, and vibration displacement is reduced in this area. The thinner area vibrates with higher amplitude, inducing mechanical pressure on the dorsal area adjacent to the crista acustica. We present a new model showing how the thickened region might confer a mechanical gain onto the activation of the crista acustica sensory neurons during the sound-induced oscillations.

}, keywords = {ensiferan ear, laser vibrometry, mechanical tuning, tympanum vibration, weta}, doi = {10.1242/jeb.050187}, url = {http://jeb.biologists.org/cgi/doi/10.1242/jeb.050187https://syndication.highwire.org/content/doi/10.1242/jeb.050187}, author = {Lomas, K. and Montealegre-Z, F. and Parsons, S. and Field, L. H. and Daniel Robert} } @article {53306, title = {Substrate-Borne Vibration Mediates Intrasexual Agonism in the New Zealand Cook Strait Giant Weta (Deinacrida rugosa)}, journal = {Journal of Insect Behavior}, year = {2018}, month = {Dec-11-2018}, abstract = {

Substrate-borne vibrational communication is a common mode of information transfer in many invertebrate groups, with vibration serving as both primary and secondary signal channels in Orthopterans. The Cook Strait giant weta, Deinacrida rugosa (Orthoptera: Anostostomatidae), is an endangered New Zealand insect whose communication system has not been previously described. After field observations of intraspecific interactions in D. rugosa provided preliminary evidence for substrate-borne vibrational communication in the species, we sought to identify the following: vibrational signal structure, the mechanism of signal production, whether signal production is a sexually dimorphic trait, whether substrate-borne signals encode information regarding sender size, the primary social context in which vibration is utilized and finally, the function of vibrational signaling in the species. We used laser Doppler vibrometry to show that D. rugosa males produce low frequency (DF\ =\ 37.00\ \±\ 1.63 Hz) substrate-borne vibrations through dorso-ventral tremulation. Rarely produced by females, male signals appear to target rivals while both are in the direct physical presence of a female. Tremulatory responses to playbacks were only produced by males in male-male-female trial contexts, and neither sex exhibited walking vibrotaxis to playback signals, indicating that substrate-borne vibrational signals are not likely a component of the courtship repertoire. While we found that vibrational signal structure was not closely related to signaler size, males that initiated male-male signaling bouts held a significant advantage in contests.

}, keywords = {Agonism, Deinacrida rugosa, giant weta, seismic signals, substrate-borne signals, vibrational communication}, issn = {0892-7553}, doi = {10.1007/s10905-018-9700-2}, url = {http://link.springer.com/10.1007/s10905-018-9700-2}, author = {Howard, Daniel R. and Schmidt, Ashley P. and Hall, Carrie L. and Mason, Andrew C.} } @article {48122, title = {Tackling an intractable problem: Can greater taxon sampling help resolve~relationships within the Stenopelmatoidea (Orthoptera: Ensifera)?}, journal = {Zootaxa}, volume = {4291}, year = {2017}, month = {Nov-07-2017}, pages = {1}, abstract = {

The relationships among and within the families that comprise the orthopteran superfamily Stenopelmatoidea (suborder Ensifera) remain poorly understood. We developed a phylogenetic hypothesis based on Bayesian analysis of two nuclear ribosomal and one mitochondrial gene for 118 individuals (84 de novo and 34 from GenBank). These included Gryllacrididae from North, Central, and South America, South Africa and Madagascar, Australia and Papua New Guinea; Stenopelmatidae from North and Central America and South Africa; Anostostomatidae from North and Central America, Papua New Guinea, New Zealand, Australia, and South Africa; members of the Australian endemic Cooloola (three species); and a representative of Lezina from the Middle East. We also included representatives of all other major ensiferan families: Prophalangopsidae, Rhaphidophoridae, Schizodactylidae, Tettigoniidae, Gryllidae, Gryllotalpidae and Myrmecophilidae and representatives of the suborder Caelifera as outgroups. Bayesian analyses of concatenated sequence data supported a clade of Stenopelmatoidea inclusive of all analyzed members of Gryllacrididae, Stenopelmatidae, Anostostomatidae, Lezina and Cooloola. We found Gryllacrididae worldwide to be monophyletic, while we did not recover a monophyletic Stenopelmatidae nor Anostostomatidae. Australian Cooloola clustered in a clade composed of Australian, New Zealand, and some (but not all) North American Anostostomatidae. Lezina was included in a clade of New World Anostostomatidae. Finally, we compiled and compared karyotypes and sound production characteristics for each supported group. Chromosome number, centromere position, drumming, and stridulation differed among some groups, but also show variation within groups. This preliminary trait information may contribute toward future studies of trait evolution. Despite greater taxon sampling within Stenopelmatoidea than previous efforts, some relationships among the families examined continue to remain elusive.

}, keywords = {Anostostomatidae, Cooloola, drumming, genetic, Gryllacrididae, karyotype, Lezina, Orthoptera, sound production, Stenopelmatidae}, issn = {1175-5326}, doi = {10.11646/zootaxa.4291.110.11646/zootaxa.4291.1.1}, url = {https://biotaxa.org/Zootaxa/issue/view/zootaxa.4291.1https://biotaxa.org/Zootaxa/article/view/zootaxa.4291.1.1}, author = {Amy G. Vandergast and David B. Weissman and Dustin A. Wood and D. C. F. Rentz and Corinna S. Bazelet and Norihiro Ueshima} } @article {40445, title = {Reproductive Behavior of Ground Weta (Orthoptera: Anostostomatidae): Drumming Behavior, Nuptial Feeding, Post-copulatory Guarding and Maternal Care}, journal = {Journal of the Kansas Entomological Society}, volume = {77}, year = {2004}, pages = {414-428}, chapter = {414}, abstract = {

Compared to other ensiferan Orthoptera such as true crickets (Gryllidae) and katydids (Tettigoniidae) relatively little is known about the reproductive behavior of Anostostomatidae (formerly Stenopelmatidae), the king crickets, weta and allies. Moreover, although the New Zealand species (the weta) are best known, there is little knowledge of the biology of ground weta (Hemiandrus species), a variable genus especially with regard to ovipositor length. This paper presents observations of mating and post-mating behavior of several Hemiandrus species with short ovipositors. Sexually active males and females drum their abdomens on the substrate, apparently as local signals for mate attraction (pheromones may be involved in long distance communication). After mating there is both maternal and paternal investment. Females provide care to eggs and young larvae and males provide a spermatophylax to the female, a mating meal that, in other ensiferan Orthoptera can be an important source of nutrition. In contrast to other ensiferans, however, the spermatophylax of Hemiandrus species with short ovipositors is deposited on the female\’s abdomen, a separate location from the sperm ampulla. The spermatophylax is deposited while the male is attached to the female\’s underside, apparently to her modified 6th abdominal sternite. Also, in contrast to related taxa, males remain with their mates while the mating meal is eaten. These observations indicate that ground weta are excellent systems for examining behavioral and ecological questions about the evolution of complex signals, as well as the evolution of maternal and paternal investment.

}, keywords = {communication, Hemiandrus, mating behavior, parental investment}, url = {http://www.jstor.org/stable/25086232 }, author = {Darryl T. Gwynne} } @article {40443, title = {The World{\textquoteright}s Most Unusual Gryllacridid (Orthoptera: Gryllacrididae)}, journal = {Journal of Orthoptera Research}, volume = {6}, year = {1997}, pages = {57-68}, chapter = {57}, abstract = {

Gryllacridid behavior and morphology is referred to an unusual Raspy Cricket from south-east Queensland is described in a new genus and species, Urogryllacris gwinganna gen. \& sp. nov. The species is unique in the Gryllacrididae in having an extraordinarily developed male subgenital plate which terminates in an elongate whip-like structure. The new genus and species are described with emphasis given to the proventriculus, the male subgenital plate and the egg. A mating sequence is described with a discussion concerning the possible function of the peculiar subgenital plate.

}, url = { http://www.jstor.org/stable/3503536}, author = {D. C. F. Rentz} } @article {40441, title = {Neuroanatomy of the complex tibial organ of Stenopelmatus (Orthoptera: Ensifera: Stenopelmatidae)}, journal = {The Journal of Comparative Neurology}, volume = {511}, year = {2008}, month = {Jan-11-2008}, pages = {81 - 91}, abstract = {

Stenopelmatidae (or \“Jerusalem crickets\”) belong to the atympanate Ensifera, lacking hearing organs in the foreleg tibiae. Their phylogenetic position is controversial, either as a taxon in Tettigonioidea or within the clade of Gryllacridoidea. Similarly, the origin of tibial auditory systems in Ensifera is controversial. Therefore, we investigated the neuronal structures of the proximal tibiae of Stenopelmatus spec. with the hypothesis that internal sensory structures are similar to those in tympanate Ensifera. In Stenopelmatus the complex tibial organ consists of three neuronal parts: the subgenual organ, the intermediate organ, and a third part with linearly arranged neurons. This tripartite organization is also found in tympanate Ensifera, verifying our hypothesis. The third part of the sense organ found in Stenopelmatus can be regarded by the criterion of position as homologous to auditory receptors of hearing Tettigonioidea. This crista acustica homolog is found serially in all thoracic leg pairs and contains 20 \± 2 chordotonal neurons in the foreleg. The tibial organ was shown to be responsive to vibration, with a broad threshold of about 0.06 ms\−2 in a frequency range from 100\–600 Hz. The central projection of tibial sensory neurons terminates into two equally sized lobes in the primary sensory neuropil, the medial ventral association center. The data are discussed comparatively to those of other Ensifera and mapped phylogenetically onto recently proposed phylogenies for Ensifera. The crista acustica homolog could represent a neuronal rudiment of a secondarily reduced ear, but neuronal features are also consistent with an evolutionary preadaptation.

}, keywords = {chordotonal organ, Ensifera, neuroanatomy, sensory evolution, Stenopelmatidae, vibrational communication}, issn = {00219967}, doi = {10.1002/cne.v511:110.1002/cne.21836}, url = {http://doi.wiley.com/10.1002/cne.v511\%3A1}, author = {Strau{\ss}, Johannes and Lakes-Harlan, Reinhard} } @article {40435, title = {Neuroanatomy and Physiology of the Complex Tibial Organ of an Atympanate Ensiferan, Ametrus tibialis (Brunner von Wattenwyl, 1888) (Gryllacrididae, Orthoptera) and Evolutionary Implications}, journal = {Brain, Behavior and Evolution}, volume = {71}, year = {2008}, month = {Jan-01-2008}, pages = {167 - 180}, abstract = {

We investigated the neuroanatomy and physiology of the complex tibial organ of an atympanate ensiferan, the Gryllacridid Ametrus tibialis. This represents the first analysis of internal mechanoceptors in Gryllacridids. The complex tibial organ is tripartite consisting of a subgenual organ, intermediate organ and a homologue organ to the crista acustica of tympanate ensiferan taxa of Tettigoniidae, Haglidae, and Anostostomatidae. The crista homologue contains 23 \± 2 receptor neurons in the foreleg. It is associated with the leg trachea and found serially in all three thoracic leg pairs. Central projections of the sensory nerve of the complex tibial organ bifurcate in two lobes in the prothoracic ganglion, which do not reach the midline. The axonal endings project into the mVAC, the main vibratory-auditory neuropile of Ensifera. Recordings of the tibial nerve show that the tibial organ is sensitive to vibrational stimuli with a minimum threshold of 0.02 to 0.05 ms\–2 at 200\–500 Hz, but rather insensitive to airborne sound. The main function of the tibial organ is therefore vibration sensing, although the specific function of the crista homologue remains unclear. The presence of the crista acustica homologue is interpreted in phylogenetic context. Because ensiferan phylogeny is unresolved, two alternative scenarios can be deduced: (a) the crista homologue is a precursor structure which was co-opted as an auditory system and represent a morphologically highly specialized structure before acquisition of its new function; (b) a previously functional tibial ear is evolutionary reduced but the neuronal structures are maintained. Based on comparison of neuroanatomical details, the crista acustica homologue of A. tibialis could present the neuronal complement of an ear evolutionary precursor structure, which was successively made sensitive to airborne sound by elaboration of cuticular tympana, auditory spiracle and trachea for sound propagation.

}, keywords = {Ametrus tibialis, auditory system, Ensifera, Gryllacrididae, hearing organ, neuroanatomy, vibrational communication}, issn = {0006-8977}, doi = {10.1159/000114405}, url = {http://www.karger.com/doi/10.1159/000114405}, author = {Strau{\ss}, Johannes and Lakes-Harlan, Reinhard} } @article {40433, title = {Sound production in primitive Orthoptera from Western Australia: sounds used in defence and social communication in Ametrus sp. and Hadrogryllacris sp. (Gryllacrididae: Orthoptera)}, journal = {Journal of Natural History}, volume = {31}, year = {1997}, month = {Jan-07-1997}, pages = {1127 - 1141}, abstract = {

Sound production in two undescribed species of Gryllacrididae belonging to the genus Ametrus sp. and Hadrogryllacris sp. takes the form of defensive stridulation and intra-specific signalling by drumming on the substrate. Defensive stridulation is produced as part of an elaborate visual display, by femoro-tergal stridulation. Two rows of spines on abdominal tergites II and III of both species are rubbed by an elongate area of tubercules on the inner femoral surface of the hind legs. Analysis showed that the motion of the leg relative to the abdomen involves a complex counter-rotation of the leg between leg and abdomen. The defensive display may be performed in day light. Social signalling in both species occurs after dark, and involves drumming on the substrate by both hind legs in loose synchrony. Drumming is rhythmic and species\&$\#$39; specific. Males respond to playback calls and females duet with males. The evolution of this calling behaviour is discussed and comparisons are made with the other primitive ensiferan family known to produce both tergo-abdominal defensive stridulation and femoral drumming behaviour, the Stenopelmatidae.

}, keywords = {defence, duetting, social communication, sound production, substrate vibration}, issn = {0022-2933}, doi = {10.1080/00222939700770591}, url = {http://www.tandfonline.com/doi/abs/10.1080/00222939700770591}, author = {Field, L.H. and Winston J. Bailey} } @inbook {40322, title = {Communication and Reproductive Behaviour in North American Jerusalem Crickets (Stenopelmatus) (Orthoptera: Stenopelmatidae)}, booktitle = {The Biology of Wetas, King Crickets and their Allies}, year = {2001}, pages = {351-375}, publisher = {CABI}, organization = {CABI}, chapter = {19}, address = {Wallingford, United Kingdom}, issn = {0851994083}, author = {David B. Weissman} }