Krugner R, Gordon SD.  2018.  Mating disruption of Homalodisca vitripennis (Germar) (Hemiptera: Cicadellidae) by playback of vibrational signals in vineyard trellis.  Journal of Pest Management Science.

Krugner R, Gordon SD. 2018. Mating disruption of Homalodisca vitripennis (Germar) (Hemiptera: Cicadellidae) by playback of vibrational signals in vineyard trellis. Journal of Pest Management Science.

BACKGROUND Glassy-winged sharpshooter (GWSS), Homalodisca vitripennis (Germar) (Hemiptera: Cicadellidae) is an important vector of the bacterium Xylella fastidiosa, the causal agent of Pierce’s disease of grapevine. Area-wide insecticide applications have suppressed GWSS populations for ca. 25 years, but reduced levels of insecticide susceptibility have been reported. Therefore, alternative methods of control are needed. Objectives of this study were to evaluate efficacy of playback of vibrational mating communication signals for disrupting mating of GWSS in a natural vineyard setting and evaluate spectral properties of signal transmission through vineyard trellis. RESULTS Playback reduced mating of GWSS on grapevines. A total of 28 (out of 134) male-female pairs mated in the control treatment (silence) and only one (out of 134) pair mated when treated with the vibrational signal playback. Playback of vibrational signals through vineyard trellis was affected by distance from signal source, with frequency composition and intensity being the highest at the signal source and lowest on vines positioned away from the source. Frequency composition in canes housing test insects decreased exponentially as distance from the source increased, whereas the relative amplitude of analyzed frequencies decreased linearly. CONCLUSION Although further studies are needed prior to method implementation, data from this study continue to support integration of vibrational mating disruption with current methods to suppress GWSS populations.   Krugner and Gordon.  2018.  Mating disruption of Homalodisca vitripennis (Germar) (Hemiptera: Cicadellidae) by playback of vibrational signals in vineyard trellis.   Pest Management Science....
Mazzoni V, Gordon SD, Nieri R, Krugner R.  2017.  Design of a candidate vibrational signal for mating disruption against the glassy-winged sharpshooter, Homalodisca vitripennis, Pest Management Science. 73:2328-2333.

Mazzoni V, Gordon SD, Nieri R, Krugner R. 2017. Design of a candidate vibrational signal for mating disruption against the glassy-winged sharpshooter, Homalodisca vitripennis, Pest Management Science. 73:2328-2333.

The glassy-winged sharpshooter (GWSS), Homalodisca vitripennis, is an important pest of grapevines due to its ability to transmit Xylella fastidiosa, the causal agent of Pierce’s disease. GWSS mating communication is based on vibrational signals; therefore, vibrational mating disruption could be an alternative to insecticides for suppression of GWSS population. Our objectives were to identify spectral features of female signal that elicit male signaling, design disruptive signals able to alter male perception and acceptance of a female, and determine the signal intensity required for future field applications. Results showed that male responses to playback of modified female signals were significantly reduced by 60-75%when part of the female signal spectral components above or below 400 Hz were deleted. Playback bioassays showed that transmission of an 80 Hz pure frequency tone to plants completely suppressed male signaling to female signal playback, even if the disruptive signal amplitude was 10 dB lower than the female signal playback.  Although the mechanism underlying cessation of male signaling activity in the presence of disruption is not yet understood, results suggest that an 80 Hz vibrational signal should be tested in laboratory and field experiments to assess its efficacy in disrupting mating of GWSS Mazzoni V, Gordon SD, Nieri R, Krugner R. 2017. Design of a candidate vibrational signal for mating disruption against the glassy-winged sharpshooter, Homalodisca vitripennis, Pest Management Science....
Gordon SD, Sandoval N, Mazzoni V, Krugner R.  2017.  Mating interference of glassy-winged sharpshooters, Homalodisca vitripennis.  Entomologia Experimentalis et Applicata. 164:27-34

Gordon SD, Sandoval N, Mazzoni V, Krugner R. 2017. Mating interference of glassy-winged sharpshooters, Homalodisca vitripennis. Entomologia Experimentalis et Applicata. 164:27-34

Animal communication is a complex behavior that is influenced by abiotic and biotic factors of the environment.  Glassy-winged sharpshooters (GWSS), Homalodisca vitripennis (Germar) (Hemiptera: Cicadellidae), primarily use vibrational signaling for courtship communication.  Because GWSS is a major pest, transmitting the plant pathogenic bacterium Xylella fastidiosa, interruption of communication is a possible avenue for control.  Playback of white noise, pre-recorded female signals, and artificial female noise (continuously overlapping female signals) significantly reduced mating of GWSS when compared to silent control mating trials.  Furthermore, to begin to determine the mechanism underlying playback control, female signaling activity was recorded in the presence of stimuli.  In response to playback of female signals, females signaled (duet-like) more often than females tested in the absence of playback.  After the first playback, almost two-thirds of females signaled a response within 3s.  Additionally, one-third of the females signaled within 1s after cessation of white noise, and significantly more in the time periods following noise termination.  Results highlight how GWSS responds to differing competitive disturbances in the environment and lays important ground work that possibly could be used to develop pesticide-free control methods.   Gordon SD, Sandoval N, Mazzoni V, Krugner R. 2017. Mating interference of glassy-winged sharpshooters, Homalodisca vitripennis. Entomologia Experimentalis et Applicata....
Nieri R, Mazzoni V, Gordon SD, Krugner R.  2017.  Mating behavior and vibrational mimicry in the glassy-winged sharpshooter, Homalodisca vitripennis. Journal of Pest Science. 90:887-889

Nieri R, Mazzoni V, Gordon SD, Krugner R. 2017. Mating behavior and vibrational mimicry in the glassy-winged sharpshooter, Homalodisca vitripennis. Journal of Pest Science. 90:887-889

The glassy-winged sharpshooter (GWSS), Homalodisca vitripennis, is an important vector of Xylella fastidiosa, the causal agent of Pierce’s disease of grapevine. GWSS control relies mainly on insecticides; therefore, an alternative method, such as vibrational mating disruption, is required. However, knowledge of GWSS intraspecific communication is necessary to evaluate applicability of such methods. Mating behavior and associated vibrational signals were described in different social contexts: individuals, pairs, and one female with two competing males. Behavioral analysis showed that GWSS mating communication involved the emission of three male and two female signals, with specific roles in two distinct phases of mating behavior, identification and courtship. Mating success depended on vibrational duets between genders, which were temporarily interrupted in the presence of male rivalry. Male rivalry behavior involved the emission of three distinct rivalry signals. Two rivalry signals resemble female signals and were associated with replacement of the female in the duet by the rival male. The third rivalry signal was emitted by competing males. Data suggested that rival males used mimicry and hostile signals to interrupt the ongoing duet and gain access to a female. In the future, knowledge acquired from this study will be essential to develop a mechanical mating disruption method for GWSS control. Nieri R, Mazzoni V, Gordon SD, Krugner R. 2017. Mating behavior and vibrational mimicry in the glassy-winged sharpshooter, Homalodisca vitripennis. Journal of Pest Science....
Sitvarin M, Gordon SD, Uetz GW, Rypstra A.  2016.  The wolf spider Pardosa milvina detects predator threat level using only vibratory cues.  Behaviour.  153:159-173

Sitvarin M, Gordon SD, Uetz GW, Rypstra A. 2016. The wolf spider Pardosa milvina detects predator threat level using only vibratory cues. Behaviour. 153:159-173

Predators may inadvertently signal their presence and threat level by way of signals in multiple modalities. We used a spider, Pardosa milvina, known to respond adaptively to chemotactile predator cues (i.e., silk, faeces and other excreta) to evaluate whether it could also discriminate predation risk from isolated vibratory cues. Vibrations from its prey, conspecifics, and predators (Tigrosa helluo and Scarites quadriceps) were recorded and played back to Pardosa. In addition, we recorded predator vibrations with and without access to chemotactile cues from Pardosa, indicating the presence of prey. Pardosa did not appear to discriminate between vibrations from prey or conspecifics, but the response to predators depended on the presence of cues from Pardosa. Vibrations from predators with access to chemotactile cues from prey induced reductions in Pardosa activity. Predator cues typically occur in multiple modalities, but prey are capable of imperfectly evaluating predation risk using a limited subset of information. Sitvarin M, Gordon SD, Uetz GW, Rypstra A.  2016.  The wolf spider Pardosa milvina detects predator threat level using only vibratory cues.  Behaviour. ...
Mortimer B, Gordon SD, Holland C, Siviour CR, Vollrath F, Windmill JFC. 2014. The Speed of Sound in Silk: Linking Material Performance to Biological Function. Adv. Mater. 26:5179-5183.

Mortimer B, Gordon SD, Holland C, Siviour CR, Vollrath F, Windmill JFC. 2014. The Speed of Sound in Silk: Linking Material Performance to Biological Function. Adv. Mater. 26:5179-5183.

Whilst renowned for exceptional mechanical properties, [ 1 ] little is known about the sonic properties of silk. This is surprising given its widespread use by the spider for remote sensing and communication, as well as current industrial research efforts in the production of multifunctional materials. [ 2,3 ] To address this gap in our knowledge and provide further bioinspiration, this paper presents a systematic study confirming the physical basis of spider silk’s sonic properties through a unique combination of laser vibrometry and high-rate ballistic impact. We report that modification of silk’s modulus allows the spider to finely control the sonic properties: achieved either actively by spider spinning behavior or passively in response to the environment. Interpreting our results in the context of whole webs, we propose silk fi bers are “tuned” to a resonant frequency that can be accessed through spider “plucking” behavior, which enables them to locate both prey and structural damage. Through comparison to cocoon silk and other industrial fibers, we find that spider dragline silk has the largest wavespeed range of any known material, making it an ideal model for fabrication of adjustable, green multifunctional materials.   Mortimer B, Gordon SD, Holland C, Siviour CR, Vollrath F, Windmill JFC. 2014. The Speed of Sound in Silk: Linking Material Performance to Biological Function. Adv. Mater....
Uetz GW, Roberts JA, Clark DL, Gibson JS, Gordon SD.  2013.  Active space of multimodal signals of wolf spiders in a complex litter environment.  Behavioral Ecology & Sociobiology. 67:1471-1482

Uetz GW, Roberts JA, Clark DL, Gibson JS, Gordon SD. 2013. Active space of multimodal signals of wolf spiders in a complex litter environment. Behavioral Ecology & Sociobiology. 67:1471-1482

Abstract Multimodal signals may compensate for environmental constraints on communication, as signals in different modalities vary in efficacy. We examined the influence of complex microhabitats on transmission of vibratory and visual signals of courting male Schizocosa ocreata wolf spiders (Araneae: Lycosidae) with laser Doppler vibrometry (LDV) and behavioral observations in lab and field. We measured maximum potential detection distance of visual and vibratory signals by females in laboratory mesocosms, recorded vibration signal attenuation on different substrates, and estimated transmission distances for male vibration signals in the field. We also determined effective line-of sight visual detection distances in the field with laser distance measures. Together, these data were used to estimate the potential and effective active space of multimodal signals. LDV measures show leaves are highly conductive substrates for wolf spider vibratory signals compared to others (soil, wood, rock). For both visual and vibratory modes, lab estimates of maximum potential distance for signal transmission and detection (behavior studies) exceeded estimates of effective active space (signal attenuation, “vanishing point,” and “line-of-sight” measures). Field estimates of transmission distance for signal modes overlap, such that in close range (<20 cm), vibratory signals are more likely to be detected, while farther away, visual signals are more likely to be seen. These findings thus support current  hypotheses regarding how multimodal communication might extend the range of overall signal active space or compensate for environmental constraints. Uetz GW, Roberts JA, Clark DL, Gibson JS, Gordon SD.  2013.  Active space of multimodal signals of wolf spiders in a complex litter environment.  Behavioral Ecology & Sociobiology. 67:1471-1482...
Gordon SD, Uetz GW.  2012.  Environmental interference: impact of acoustic noise on seismic communication and mating success.  Behavioral Ecology. 23:700-714.

Gordon SD, Uetz GW. 2012. Environmental interference: impact of acoustic noise on seismic communication and mating success. Behavioral Ecology. 23:700-714.

Sound is abundant in the environment, often creating ‘‘noise’’ that interferes with animal communication. Animals cope with acoustic interference in a variety of ways, including raising their signal volume (the Lombard effect), changing the pattern, frequency or duration of signals, or changing the time of day when signaling. Although many arthropods use substrate-borne vibration (seismic) signals, the effect of interference from (airborne) acoustic noise on their communication is not well studied. We tested the effects of 3 different types of airborne acoustic sounds on substrate-borne seismic communication and mating success of the ground-dwelling wolf spider, Schizocosa ocreata. We used band-limited white noise (0–4 kHz), predatory bird calls (northern cardinal Cardinalis cardinalis), and a cicada chorus (mixed Magicicada spp.) as interference stimuli. Spider behavior and mating success were differentially affected by each type of environmental acoustic sound. Males took longer to initiate courtship with bird calls, although white noise and cicada calls did not affect male signaling. Females oriented toward males more often with white noise but showed no change in their orientation behavior with bird or cicada calls. Finally, female receptivity and mating success were reduced with white noise and bird calls, whereas cicada calls had no effect. Our data suggest that wolf spiders using seismic vibration in communication respond differently to various types of airborne sounds, transmitted as vibrations, in their environment. This work is among the first to highlight how airborne sounds create seismic interference differentially affecting the behaviors of arthropods living in the leaf litter. Key words: behavioral plasticity, bioacoustics, bird song, cicada, communication, environment, interference, Schizocosa ocreata, sound, vibration, wolf spider. [Behav Ecol]   Gordon...
Gordon SD, Uetz GW.  2011.  Multimodal communication of wolf spiders on different substrates:  evidence for behavioral flexibility.  Animal Behaviour.  81:367-375.

Gordon SD, Uetz GW. 2011. Multimodal communication of wolf spiders on different substrates: evidence for behavioral flexibility. Animal Behaviour. 81:367-375.

Communication in complex environments poses challenges of potential loss of intended messages, but some animals may compensate by using multimodal signalling. Courtship displays of male Schizocosa ocreata (Hentz) wolf spiders are multimodal, consisting of visual and seismic signals. The microhabitat of S. ocreata is complex, including leaf litter, wood/bark, soil and rocks. Results from laser vibrometer measurements in the present study indicated that leaf litter transmitted male courtship signals with greater efficacy. Mating success was significantly greater on leaf litter (∼85%) compared to other substrates (∼30%), even though latency to male courtship did not vary among substrates. Given these results, selection should favour spiders that increase their mating potential on nonconducting substrates. We tested whether spiders detect substrate differences in a choice test, and found that when males and females visited all substrates, they spent significantly more time on leaf litter. We isolated courting male spiders on each substrate and scored courtship behaviours to see whether signals varied with substrate. Males used significantly more visual signals (waves and arches) on substrates that attenuated seismic signals (soil and rocks), but other behaviours showed no differences. Taken together, these results suggest that combined visual/seismic components of multimodal displays may serve as ‘backup signals’, ensuring reception under different environmental conditions. Results also suggest that male S. ocreata have the flexibility to compensate for environmental constraints by seeking microhabitats with more effective vibration conduction properties, and/or by increasing visual signals on substrates where seismic communication is less effective. Gordon SD, Uetz GW.  2011.  Multimodal communication of wolf spiders on different substrates:  evidence for behavioral flexibility.  Animal Behaviour. ...
Lohrey AK, Clark DL, Gordon SD, Uetz GW.  2009.  Anti-predator responses of wolf spiders (Araneae:  Lycosidae) to sensory cues representing an avian predator.  Animal Behaviour.  77:813-821.

Lohrey AK, Clark DL, Gordon SD, Uetz GW. 2009. Anti-predator responses of wolf spiders (Araneae: Lycosidae) to sensory cues representing an avian predator. Animal Behaviour. 77:813-821.

Predator detection and subsequent antipredator response behaviours have been documented in many vertebrate and invertebrate animals, although the degree of specificity in predator recognition and response varies. We examined responses of actively courting adult male Schizocosa ocreata (Hentz) wolf spiders to cues indicating the presence of an avian predator, including visual, seismic (substrate vibration) and acoustic (airborne) stimuli. Spiders responded to acoustic (bird call) and seismic (simulated beak tap) stimuli with cessation of courtship and movement, but increased locomotion when presented with a visual stimulus (bird shadow). Spiders responded to experimental playback of avian acoustic stimuli with antipredator behaviour significantly more often and took longer to return to courtship than when exposed to nonthreatening stimuli. Tests of responses on different substrata to isolate sensory modes revealed that spiders perceive airborne sound from bird calls as substratum-conducted vibration. Results indicate that S. ocreata are capable of recognizing sensory cues associated with avian predators and distinguishing them from nonthreatening stimuli, suggesting that bird predation has been a selection factor in shaping behaviour of this wolf spider species. Lohrey AK, Clark DL, Gordon SD, Uetz GW.  2009.  Anti-predator responses of wolf spiders (Araneae:  Lycosidae) to sensory cues representing an avian predator.  Animal Behaviour. ...