Vibrational directionality in the southern green stink bug, Nezara viridula (L.), is mediated by female song

The role of signals of different modalities in initiating vibratory communication in Nezara viridula

“…It cannot be a response to another vibrational song and we have no indication of any female-emitted chemical substances that would induce male calling [10,[22][23][24][25]. Other vibrations induced, for example, by walking, tapping a plant etc.…”

“…In most cases when a female starts vibrational communication on a plant she emits the calling song. This increases male activity in searching for her on the plant [25], enables vibrational directionality [25], triggers male vibratory responses [28] and increases male pheromone release [12]. FCS is usually the first female song and is the song that enables males to find females and its time parameters are very distinct no matter where she sings [26].…”

Search behaviour of two hemipteran species using vibrational communication

“…We monitored the following parameters that were used to describe male mate searching behaviour in N. viridula in previous studies [19][20][21][22]: number of males emitting vibrational signals (male courtship song [18]), duration of male courtship song, number of males searching (defined as singing and moving [19]), number of signals emitted during walking, search latency (time needed to start moving after the start of stimulation), number of males locating the vibration source and searching time (time needed to locate the source after the onset of searching). The male was recorded as locating the source if he reached the exciter or the top of the vibrated leaf and stayed there for 3 min or until the end of the trial, whichever came first.…”

“…First, a stereotyped male-female duet is not formed during the initial advertising stage ( Figure 1A). One partner (male in this case) identifies another one (the female) via the temporal pattern of her continuously emitted calling song and locates her on the plant [19][20][21][22]. Second, male vibrational signals do not trigger female calling [21], while females emit their calling song continuously with stable signal repetition rate for several minutes in the absence of male vibrational signals [23,24].…”

“…Second, male vibrational signals do not trigger female calling [21], while females emit their calling song continuously with stable signal repetition rate for several minutes in the absence of male vibrational signals [23,24]. Emission of female vibrational signals is triggered by male sex pheromone [23] and the female calling song, in turn, triggers the emission of male courtship song [17] and searching behaviour [19]. The role of male vibrational signals and importance of their specificity during the initial advertising and searching stage is not clear [17] however, they may provide the information for the female that male is on the same plant and thus help to maintain the emission of female calling song for a longer time to enable successful localization.…”