Reproductive Character Displacement and Speciation in Periodical Cicadas, With Description of a New Species, 13-Year Magicicada Neotredecim

Abstract

Abstract. Acoustic mate‐attracting signals of related sympatric, synchronic species are always distinguishable, but those of related allopatric species sometimes are not, thus suggesting that such signals may evolve to “reinforce” premating species isolation when similar species become sympatric. This hypothesis predicts divergences restricted to regions of sympatry in partially overlapping species, but such “reproductive character displacement” has rarely been confirmed. We report such a case in the acoustic signals of a previously unrecognized 13‐year periodical cicada species, Magicicada neotredecim, described here as a new species (see Appendix). Where M. neotredecim overlaps M. tredecim in the central United States, the dominant male call pitch (frequency) of M. neotredecim increases from approximately 1.4 kHz to 1.7 kHz, whereas that of M. tredecim remains comparatively stable. The average preferences of female M. neotredecim for call pitch show a similar geographic pattern, changing with the call pitch of conspecific males. Magicicada neotredecim differs from 13‐year M. tredecim in abdomen coloration, mitochondrial DNA, and call pitch, but is not consistently distinguishable from 17‐year M. septendecim; thus, like other Magicicada species, M. neotredecim appears most closely related to a geographically adjacent counterpart with the alternative life cycle. Speciation in Magicicada may be facilitated by life‐cycle changes that create temporal isolation, and reinforcement could play a role by fostering divergence in premating signals prior to speciation. We present two theories of Magicicada speciation by life‐cycle evolution: “nurse‐brood facilitation” and “life‐cycle canalization.”

Molecular species delimitation methods recover most song‐delimited cicada species in the European Cicadetta montana complex

“…Male cicadas produce airborne calling songs that signal mating availability to females. Calling songs thus function as species specific mate recognition signals (Dugdale & Fleming, ; Marshall & Cooley, ; Cooley & Marshall, ; Gogala & Trilar, ; Sueur & Aubin, ; Marshall et al ., ; Gogala, ) that can be used to separate species faster than morphological or molecular differences (Popple et al ., ; Marshall et al ., ; Popple, ; Nunes et al ., ; Hertach et al ., ). Song differences often precede morphological differentiation (Hill et al ., ; Marshall et al ., ).…”

Reproductive Character Displacement in the Acoustic Communication System of Green Tree Frogs (Hyla Cinerea)

“…In some systems, shifts in female preferences may subsequently select for additional divergence in male secondary sexual traits that facilitate species recognition (e.g., Saetre et al 1997). In fact, geographic variation in receiver selectivity has been assessed in a growing number of recent studies that have provided various degrees of empirical support for reproductive character displacement (Gerhardt 1994(Gerhardt , 1999Noor 1995;Marquez and Bosch 1997;Saetre et al 1997;Rundle and Schluter 1998;Pfennig 2000;Marshall and Cooley 2000;Gabor and Ryan 2001).…”

Reproductive Character Displacement and the Genetics of Gamete Recognition in Tropical Sea Urchins

“…Grant (1972) identified a number of practical difficulties in detecting character displacement, including the difficulty in distinguishing true displacement caused by the presence of another species from variation caused by adaptation to environmental variables. Although reproductive character displacement has been demonstrated in a number of species (Bordenstein et al 2000;Kulathinal and Singh 2000;Marshal Simon et al 2000; but see Noor et al 2000), only a few have clearly demonstrated a role for selection in this divergence. These include Drosophila (Higgie et al 2000), flycatchers (Saetrre et al 1997(Saetrre et al , 1999, sticklebacks (Hatfield and Schluter 1996;Hatfield 1997;Rundle and Schluter 1998), whitefish (Bernatchez et al 1996;Pigeon et al 1997;Lu and Bernatchez 1998), and ground crickets ).…”