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....
Gordon SD, Klenschi E, Windmill JFC.  2017.  Hearing on the fly: the effects of wing position on noctuid moth hearing.  Journal of Experimental Biology. 220:1952-1955

Gordon SD, Klenschi E, Windmill JFC. 2017. Hearing on the fly: the effects of wing position on noctuid moth hearing. Journal of Experimental Biology. 220:1952-1955

The ear of the noctuid moth has only two auditory neurons, A1 and A2, which function in detecting predatory bats. However, the noctuid’s ears are located on the thorax behind the wings. Therefore, since these moths need to hear during flight, it was hypothesized that wing position may affect their hearing. The wing was fixed in three different positions: up, flat, and down. An additional subset of animals was measured with freely moving wings. In order to negate any possible acoustic shadowing or diffractive effects, all wings were snipped, leaving the proximal most portion and the wing hinge intact. Results revealed that wing position plays a factor in threshold sensitivity of the less sensitive auditory neuron A2, but not in the more sensitive neuron A1. Furthermore, when the wing was set in the down position, fewer A1 action potentials were generated prior to the initiation of A2 activity. Analyzing the motion of the tympanal membrane did not reveal differences in movement due to wing position. Therefore, these neural differences due to wing position are proposed to be due to other factors within the animal such as different muscle tensions.   Gordon SD, Klenschi E, Windmill JFC. 2017. Hearing on the fly: the effects of wing position on noctuid moth hearing. Journal of Experimental Biology....
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. ...