00237nas a2200085 4500008004100000245002400041210002200065100002000087856004400107 1877 eng d00a[Letters to Editor]0 aLetters to Editor1 aWHITE, BUCHANAN uhttp://www.nature.com/articles/015293a002528nas a2200217 4500008004100000245010300041210006900144520177600213653002701989653002202016653001602038653001202054653002102066653001202087653001902099100001702118700001902135700001902154700001702173856012002190 2011 eng d00aWhistling in caterpillars (Amorpha juglandis, Bombycoidea): sound-producing mechanism and function0 aWhistling in caterpillars Amorpha juglandis Bombycoidea soundpro3 a

Caterpillar defenses have been researched extensively, and, although most studies focus on visually communicated signals, little is known about the role that sounds play in defense. We report on whistling, a novel form of sound production for caterpillars and rare for insects in general. The North American walnut sphinx (Amorpha juglandis) produces whistle ‘trains’ ranging from 44 to 2060ms in duration and comprising one to eight whistles. Sounds were categorized into three types: broadband, pure whistles and multi-harmonic plus broadband, with mean dominant frequencies at 15kHz, 9kHz and 22kHz, respectively. The mechanism of sound production was determined by selectively obstructing abdominal spiracles, monitoring air flow at different spiracles using a laser vibrometer and recording body movements associated with sound production using high-speed video. Contractions of the anterior body segments always accompanied sound production, forcing air through a pair of enlarged spiracles on the eighth abdominal segment. We tested the hypothesis that sounds function in defense using simulated attacks with blunt forceps and natural attacks with an avian predator – the yellow warbler (Dendroica petechia). In simulated attacks, 94% of caterpillars responded with whistle trains that were frequently accompanied by directed thrashing but no obvious chemical defense. In predator trials, all birds readily attacked the caterpillar, eliciting whistle trains each time. Birds responded to whistling by hesitating, jumping back or diving away from the sound source. We conclude that caterpillar whistles are defensive and propose
that they function specifically as acoustic ‘eye spots’ to startle predators.

10aacoustic communication10aAmorpha juglandis10acaterpillar10adefense10asound production10awhistle10ayellow warbler1 aBura, V., L.1 aRohwer, V., G.1 aMartin, P., R.1 aYack, J., E. uhttp://jeb.biologists.org/cgi/doi/10.1242/jeb.046805https://syndication.highwire.org/content/doi/10.1242/jeb.04680502950nas a2200313 4500008004100000022001400041245011100055210006900166260001600235490000800251520202000259653002102279653001902300653001602319653001802335653001402353653001602367653001802383100001802401700002002419700002002439700002302459700002002482700001902502700001502521700002202536700002302558856005502581 2015 eng d a0028-104200aThe unique sound production of the Death’s-head hawkmoth (Acherontia atropos (Linnaeus, 1758)) revisited0 aunique sound production of the Death shead hawkmoth Acherontia a cJan-08-20150 v1023 a

When disturbed, adults of the Death’s-head hawkmoth (Lepidoptera, Sphingidae: Acherontia atropos) produce short squeaks by drawing in and deflating air into and out of the pharynx as a defence mechanism. We took a new look at Prell’s hypothesis of a two-phase mechanism by providing new insights into the functional morphology behind the pharyngeal sound production of this species. First, we compared the head anatomy of A. atropos with another sphingid species, Manduca sexta, by using micro-computed tomography (CT) and 3D reconstruction methods. Despite differences in feeding behaviour and capability of sound production in the two species, the musculature in the head is surprisingly similar. However, A. atropos has a much shorter proboscis and a modified epipharynx with a distinct sclerotised lobe projecting into the opening of the pharynx. Second, we observed the sound production in vivo with X-ray videography, mammography CT and high-speed videography. Third, we analysed acoustic pressure over time and spectral frequency composition of six A. atropos specimens, both intact and with a removed proboscis. Single squeaks of A. atropos last for ca. 200 ms and consist of an inflation phase, a short pause and a deflation phase. The inflation phase is characterised by a burst of ca. 50 pulses with decreasing pulse frequency and a major frequency peak at ca. 8 kHz, followed by harmonics ranging up to more than 60 kHz. The deflation phase is characterised by a less clear acoustic pattern, a lower amplitude and more pronounced peaks in the same frequency range. The removal of the proboscis resulted in a significantly shortened squeak, a lower acoustic pressure level and a slightly more limited frequency spectrum. We hypothesise that the uptake of viscous honey facilitated the evolution of an efficient valve at the opening of the pharynx (i.e. a modified epipharynx), and that sound production could relatively easily have evolved based on this morphological pre-adaptation.

10aInsect acoustics10aInsect anatomy10aInsect head10aManduca sexta10aProboscis10aVideography10aX-ray imaging1 aBrehm, Gunnar1 aFischer, Martin1 aGorb, Stanislav1 aKleinteich, Thomas1 aKühn, Bernhard1 aNeubert, David1 aPohl, Hans1 aWipfler, Benjamin1 aWurdinger, Susanne uhttp://link.springer.com/10.1007/s00114-015-1292-501844nas a2200157 4500008004100000022001400041245010600055210006900161260001600230300001400246490000800260520131000268100002001578700002201598856006601620 2018 eng d a0024-406600aHornworm counterattacks: defensive strikes and sound production in response to invertebrate attackers0 aHornworm counterattacks defensive strikes and sound production i cMay-18-2018 a496 - 5050 v1233 a

Caterpillars (i.e. lepidopteran larvae) have evolved multiple defences against predators, with some large caterpillars showing aggressive defences (e.g. strikes and/or sound production). Although such behaviours can startle or warn vertebrate predators, defences against invertebrates remain unclear. We investigated the behavioural responses of the hornworm Langia zenzeroides (Lepidoptera: Sphingidae) against the invertebrate attacker Calosoma maximowiczi (Coleoptera: Carabidae). Fifth (last) instars of L. zenzeroides exhibited a striking response, in which the larva rapidly bent its head and thorax towards the body part stimulated by C. maximowiczi attacks. Strikes were also accompanied by opening of the mandibles, followed by sound production or regurgitation. In some cases, L. zenzeroides larvae caught the legs of C. maximowiczi and threw the beetles using their mandibles. Such counterattacks completely defended against attackers. The sounds that L. zenzeroides generated (pulse durations, 82–314 ms; dominant frequencies, 5.0–8.7 kHz; sound pressure level, 44.0–56.9 dB SPL) were produced by forcing air through the eighth pair of abdominal spiracles. Our results indicate that hornworm larvae are able to deter predacious invertebrates using multiple defences.

1 aSugiura, Shinji1 aTakanashi, Takuma uhttps://academic.oup.com/biolinnean/article/123/3/496/485069202488nas a2200253 4500008004100000022001400041245008000055210006900135260002000204300001400224490000800238520158900246653001401835653002401849653001201873653001501885653002501900653002401925100003001949700002601979700002302005700002002028856018602048 2018 eng d a0022-094900aVocalization in caterpillars: a novel sound-producing mechanism for insects0 aVocalization in caterpillars a novel soundproducing mechanism fo cMay-20-20182236 ajeb1694660 v2213 a

Insects have evolved a great diversity of sound-producing mechanisms largely attributable to their hardened exoskeleton, which can be rubbed, vibrated or tapped against different substrates to produce acoustic signals. However, sound production by forced air, while common in vertebrates, is poorly understood in insects. We report on a caterpillar that ‘vocalizes’ by forcing air into and out of its gut. When disturbed, larvae of the Nessus sphinx hawkmoth (Sphingidae: Amphion floridensis) produce sound trains comprising a stereotyped pattern of long (370 ms) followed by multiple short-duration (23 ms) units. Sounds are emitted from the oral cavity, as confirmed by close-up videos and comparing sound amplitudes at different body regions. Numerical models using measurements of the caterpillar foregut were constructed to test hypotheses explaining sound production. We propose that sound is generated by ring vortices created as air flows through the orifice between two foregut chambers (crop and oesophagus), a mechanism analogous to a whistling kettle. As air flows past the orifice, certain sound frequencies are amplified by a Helmholtz resonator effect of the oesophagus chamber. Long sound units occur during inflation, while short sound units occur during deflation. Several other insects have been reported to produce sounds by forced air, but the aeroacoustic mechanisms of such sounds remain elusive. Our results provide evidence for this mechanism by showing that caterpillars employ mechanisms similar to rocket engines to produce sounds.

10aacoustics10aAmphion floridensis10adefence10aForced air10aHelmholtz resonators10aPulsating jet flows1 aRosi-Denadai, Conrado, A.1 aScallion, Melanie, L.1 aMerrett, Craig, G.1 aYack, Jayne, E. uhttp://jeb.biologists.org/lookup/doi/10.1242/jeb.169466https://syndication.highwire.org/content/doi/10.1242/jeb.169466https://syndication.highwire.org/content/doi/10.1242/jeb.16946601826nas a2200217 4500008004100000022001400041245004200055210004100097260002000138300002400158490000600182520116800188653001401356653000901370653001701379653001501396653001601411100001901427700002101446856014101467 2013 eng d a1744-956100aHawkmoths produce anti-bat ultrasound0 aHawkmoths produce antibat ultrasound cNov-20-20132082 a20130161 - 201301610 v93 a

Bats and moths have been engaged in aerial warfare for nearly 65 Myr. This arms race has produced a suite of counter-adaptations in moths, including bat-detecting ears. One set of defensive strategies involves the active production of sound; tiger moths' ultrasonic replies to bat attack have been shown to startle bats, warn the predators of bad taste and jam their biosonar. Here, we report that hawkmoths in the Choerocampina produce entirely ultrasonic sounds in response to tactile stimulation and the playback of biosonar attack sequences. Males do so by grating modified scraper scales on the outer surface of the genital valves against the inner margin of the last abdominal tergum. Preliminary data indicate that females also produce ultrasound to touch and playback of echolocation attack, but they do so with an entirely different mechanism. The anti-bat function of these sounds is unknown but might include startling, cross-family acoustic mimicry, warning of unprofitability or physical defence and/or jamming of echolocation. Hawkmoths present a novel and tractable system to study both the function and evolution of anti-bat defences.

10aarms race10abats10aecholocation10aSphingidae10asphinx moth1 aBarber, J., R.1 aKawahara, A., Y. uhttp://rsbl.royalsocietypublishing.org/cgi/doi/10.1098/rsbl.2013.0161https://syndication.highwire.org/content/doi/10.1098/rsbl.2013.016100562nas a2200157 4500008004100000022001300041245008800054210006900142260001600211100002300227700002400250700002000274700002400294700002000318856006600338 2017 eng d a0376635700aWhy do caterpillars whistle at birds? Insect defence sounds startle avian predators0 aWhy do caterpillars whistle at birds Insect defence sounds start cJan-02-20171 aDookie, Amanda, L.1 aYoung, Courtney, A.1 aLamothe, Gilles1 aSchoenle, Laura, A.1 aYack, Jayne, E. uhttp://linkinghub.elsevier.com/retrieve/pii/S0376635716303655