Phylogeography of the Poecilimon ampliatus species group (Orthoptera: Tettigoniidae) in the context of the Pleistocene glacial cycles and the origin of the only thelytokous parthenogenetic phaneropterine bush-cricket

Abstract

Parthenogenetic lineages are known to rapidly colonize large areas that become available after glacial periods as parthenogenetic reproduction is beneficial over mating when the favorable season is very short. The only obligatory parthenogenetic species of the largest bush-cricket subfamily Phaneropterinae is Poecilimon intermedius. It belongs to the Anatolio-Balkan lineage Poecilimon ampliatus species group and in contrast has a remarkably broad distribution from Central Europe to China, following the pattern of geographical parthenogenesis. In this study we provide a systematic revision of the P. ampliatus group based on mitochondrial (ND2) and nuclear (ITS) phylogeny. We estimate divergence times by applying secondary calibration on the ND2 tree to test for congruence between recent splits in the group and the Pleistocene climatic oscillations. We use ecological niche modelling to analyze the ecological requirements of the parthenogenetic P. intermedius and its sexually reproducing sister species P. ampliatus. By projecting on the conditions during the Last Glacial Maximum we outline the suitable areas for both species during the glacial cycles and discuss range shifts in response to climate change. Based on all results we hypothesize that the drought-tolerant P. intermedius originated during the recent glaciations in the southwestern part of its current range and rapidly radiated in a northeastern direction. Its sister species P. ampliatus, which is adapted to higher levels of precipitation, remained in the western Balkans, where populations retreated to higher altitudes during warming.

New insights into the genetic diversity of the Balkan bush-crickets of the Poecilimon ornatus group (Orthoptera: Tettigoniidae)

“…The time to LCA of the Poecilimon affinis complex (Fig. 2) corresponds well with the Mid-Brunhes Transition and interestingly -with the results for the two major lineage splits of the Poecilimon ampliatus complex (see Borissov et al 2021). The larger temperature amplitudes with colder glacials and a larger decrease in humidity should be the main trigger for dispersal, isolation (vicariance), extinction, and ecological adaptation in the Poecilimon affinis complex, similarly to many other animals (Hewitt 1996(Hewitt , 2000Taberlet et al 1998;Wallis et al 2016).…”

“…Poecilimon cretensis was included in the analyses based on ND2 and the age of the eastern lineage (Kotsounari) was constrained at 0.8 Ma (SD=0.2) (see also Borissov et al 2021). In order to infer the biogeographic history of the Poecilimon ornatus group, we first selected areas defined as centers of endemism.…”

“…All species of Poecilimon are shortwinged and flightless with complex acoustic communication. Cyclic glaciations during the Pleistocene influenced the diversity of the genus causing rapid radiation and diversification (La Greca 1999; Kaya et al 2015;Borissov et al , 2021.…”

“…The taxonomy and phylogenetic relationships within Poecilimon are mainly based on morphological and bioacoustic traits (e.g., Heller et al 2006Heller et al , 2011Chobanov and Heller 2010;Ingrisch and Pavićević 2010;Kaya et al 2012Kaya et al , 2018Boztepe et al 2013;Sevgili et al 2018;Chobanov et al 2020). Many species groups of this genus have been studied in terms of molecular phylogeny and biogeography (Boztepe et al 2013;Kaya et al 2015;Kaya 2018;Borissov et al , 2021 while one of the largest groups -the Poecilimon ornatus group, has only recently been considered (Kociński 2020;Kociński et al 2021). This species group contains bush-crickets distributed mostly in mountainous areas from the South-Eastern Alps to the Carpathians and Peloponnese and an isolated spot in Ukraine.…”

Origin, evolution and systematics of the genusPoecilimon(Orthoptera: Tettigoniidae)—An outburst of diversification in the Aegean area

“…The genus Poecilimon was more or less thoroughly treated in several publications concerning its systematics (Borissov et al, , 2021Boztepe et al, 2013;Chobanov et al, 2020;Chobanov & Heller, 2010;Heller, 1984;Heller et al, 2006Heller et al, , 2008Heller et al, , 2011Heller & Sevgili, 2005;Kaya, 2018;Kaya et al, 2012Kaya et al, , 2015Ramme, 1933;Sevgili et al, 2018;Ünal, 2010) and phylogeny (Borissov et al, , 2021Kaya et al, 2015;Ullrich et al, 2010).…”