@article {52680, title = {The spider-like katydid Arachnoscelis (Orthoptera: Tettigoniidae: Listroscelidinae): anatomical study of the genus}, journal = {Zootaxa}, volume = {3666}, year = {2013}, month = {Apr-06-2013}, pages = {591}, abstract = {

This paper provides some observations on the anatomy of the neotropical katydid Arachnoscelis arachnoides Karny (In- secta: Orthoptera: Tettigoniidae). Arachnoscelis is a genus of predaceous katydids that comprise species that resemble spi- ders in their general body appearance. The type species, A. arachnoids, was described in 1891 from a single male collected in Colombia. Following the original description, these creatures were never found again, and were thought to have gone extinct or mistakenly assigned to the type locality. But between 1891 and 2012 four more species were described and in- correctly assigned to Arachnoscelis based on a similarity of body form. In this paper we present an anatomical comparai- son of Arachnoscelis and its relatives, and propose that Arachnoscelis should be treated as a monotypic genus. This implies that other species previously described in Arachnoscelis, should be placed in different genera.

}, keywords = {bushcricket, Colombia, predator, stridulation, ultrasound}, issn = {1175-5326}, doi = {10.11646/zootaxa.3666.410.11646/zootaxa.3666.4.11}, url = {http://biotaxa.org/Zootaxa/issue/view/zootaxa.3666.4}, author = {Montealegre-Z, Fernando and Cadena-Castaneda, Oscar J. and Benedict D. Chivers} } @article {50909, title = {Morphological determinants of carrier frequency signal in katydids (Orthoptera): a comparative analysis using biophysical evidence}, journal = {Journal of Evolutionary Biology}, year = {2017}, month = {Apr-09-2018}, abstract = {

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\&$\#$39;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 non-functional) 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).

}, doi = {10.1111/jeb.13179}, url = {http://doi.wiley.com/10.1111/jeb.13179}, author = {Fernando Montealegre-Zapata and Ogden, Jessica and Jonsson, Thorin and Soulsbury, Carl D.} } @article {12664, title = {Shrinking Wings for Ultrasonic Pitch Production: Hyperintense Ultra-Short-Wavelength Calls in a New Genus of Neotropical Katydids (Orthoptera: Tettigoniidae)}, journal = {PLoS ONE}, volume = {9}, year = {2014}, month = {May-06-2014}, pages = {e98708}, abstract = {

This article reports the discovery of a new genus and three species of predaceous katydid (Insecta: Orthoptera) from Colombia and Ecuador in which males produce the highest frequency ultrasonic calling songs so far recorded from an arthropod. Male katydids sing by rubbing their wings together to attract distant females. Their song frequencies usually range from audio (5 kHz) to low ultrasonic (30 kHz). However, males of Supersonus spp. call females at 115 kHz, 125 kHz, and 150 kHz. Exceeding the human hearing range (50 Hz\–20 kHz) by an order of magnitude, these insects also emit their ultrasound at unusually elevated sound pressure levels (SPL). In all three species these calls exceed 110 dB SPL rms re 20 m Pa (at 15 cm). Males of Supersonus spp. have unusually reduced forewings (,0.5 mm 2 ). Only the right wing radiates appreciable sound, the left bears the file and does not show a particular resonance. In contrast to most katydids, males of Supersonus spp. position and move their wings during sound production so that the concave aspect of the right wing, underlain by the insect dorsum, forms a contained cavity with sharp resonance. The observed high SPL at extreme carrier frequencies can be explained by wing anatomy, a resonant cavity with a membrane, and cuticle deformation.

}, doi = {10.1371/journal.pone.0098708}, url = {http://dx.plos.org/10.1371/journal.pone.0098708}, author = {Sarria-S, Fabio A. and Glenn K. Morris and James F.C. Windmill and Joseph Curt Jackson and Fernando Montealegre-Zapata}, editor = {Etges, William J.} } @article {11175, title = {Ultrasonic reverse stridulation in the spider-like katydid Arachnoscelis (Orthoptera: Listrosceledinae)}, journal = {Bioacoustics}, volume = {23}, year = {2014}, month = {Feb-01-2014}, pages = {67 - 77}, abstract = {

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 of Arachnoscelis 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.

}, keywords = {biomechanics, Colombia, elastic energy, stridulation, ultrasound}, issn = {0952-4622}, doi = {10.1080/09524622.2013.816639}, url = {http://www.tandfonline.com/doi/abs/10.1080/09524622.2013.816639}, author = {Benedict D. Chivers and Jonsson, Thorin and Cadena-Castaneda, Oscar J. and Fernando Montealegre-Zapata} }