Vibrational communication and mating behavior of the meadow spittlebug Philaenus spumarius

Abstract

Vibrational pest control techniques have been recently developed for several Hemiptera, suggesting that similar strategies could be applied to other species that emit vibrational signals. To evaluate the applicability of a control method for Philaenus spumarius, the vector of Xylella fastidiosa in olive orchards in Italy, we investigated its mating behavior and characterized the associated substrate-borne signals. The vibrational signals emitted by males and females were recorded with a laser vibrometer from the surface of a leaf. Male and female repertoires consisted each of three vibrational signals with distinct features. Pair formation begun with the calling signal of a receptive female and mating was accomplished when a vibrational duet was established and maintained until the male reached the female on the plant. Female calls and duets occurred only in trials conducted in September, while earlier in the season females emitted rejection signals to courting males. Intrasexual communication between males involved the emission of vibrational signals, whose role is still not clear. Playback trials with either a female or male calling signal elicited the emission of different vibrational signals by the tested males. Further experiments with playbacks are warranted to identify vibrational signals to be used for manipulating P. spumarius behavior and develop a future control method.

Vibrational playbacks and microscopy to study the signalling behaviour and female physiology of Philaenusspumarius

“…Fourth and fifth instars nymphs of P. spumarius were collected between May and June 2018 from meadows in Riva Del Garda and San Michele all’Adige (Trentino, Italy). The collected individuals were transported to a glasshouse at the Fondazione Edmund Mach and reared in mesh cages, following the rearing protocol reported by Avosani et al., (2020). The rearing was checked every day to isolate and separate by gender the newly emerged adults, which were reared in two separate cages placed outdoors to mimic natural conditions (i.e.…”

“…immediate readiness to mate) to many months, when depending on specific growth factors such as food intake (Minelli et al., 2006). In this regard, immature females tend to show a rejective behaviour that can be expressed as simple refusal to mate or as intimidating behaviour like the emission of stress signals (Avosani et al., 2020).…”

“…Rejective behaviour has been observed in the meadow spittlebug Philaenus spumarius (Hemiptera: Aphrophoridae), whose mating behaviour mostly relies on substrate‐borne vibrations (Avosani et al., 2020).…”

“…As a consequence, research is underway to develop sustainable pest management strategies against its vector (Cornara et al., 2017, 2018; Martelli et al., 2016). In most of the Palearctic area, P. spumarius females emerge as adults in late spring (April–May), but they start to emit calling signals only at the end of the summer, while prior to this period, only males are acoustically active (Avosani et al., 2020; Witsack, 1973). In late summer, pair formation starts with the female calling signal, which is followed by the male courtship signal, which is a long and complex signal consisting of two sections that are alternatively emitted.…”

“…males search for the females, which remain stationary on the plant) and a vibrational duet is established only if the female alternates her response signals with the male courtship signal. When males happen to be in close proximity to females earlier in the season, they try to mate, and copulations are observed in the field and in the laboratory (Avosani et al., 2020; Cornara et al., 2018). However, these early matings in the spring appear imposed by the males, since immature females, at this time of the year, produce a specific rejection signal or try to escape (Avosani et al., 2020).…”