Variability of the bushcricket Ephippiger ephippiger: RAPDs and song races

Abstract

The tettigoniid bushcricket, Ephippiger, shows extensive variability in morphology and behaviour in Western Europe. Several species and subspecies have been described, but many may only represent local forms of uncertain origin. Within Ephippiger ephippiger, patterns of variation differ between morphology (upon which most taxonomic forms are defined) and behaviour. There is sufficient variation in a sexual signal (calling song) within the species that 'song races' have been described, which show strong premating isolation from each other. Here RAPD markers (138 fragments from 10 primers) have been used to examine the extent and pattern of genetic differentiation within the species and between two congeneric species. Ephippiger ephippiger is clearly distinguished from its relatives. High genetic similarity has been found within E. ephippiger, Nei and Li's S averaging 0.67. Using both distance and parsimony methods resolves the relationships of the song races and morphological forms of E. ephippiger with the exception of one population. The song races represent the deepest division within the species, but the lack of concordance in different traits suggests that a complex pattern of subspecific variation is found within this species.

An unusual phylogeography in the bushcricket Ephippiger ephippiger from Southern France

“…The mtDNA of bushcrickets from these adjoining valleys is very distinct, with net genetic distances over 10%. Similar geographically structured mtDNA variation within Pyrenean samples was suggested in a previous mtDNA RFLP analysis (Ritchie et al, 2001), although a phylogeny based on RAPDs did not show these divisions (Ritchie et al, 1997). The extent of sequence divergence is surprising, as bushcrickets from all three valleys are morphologically and behaviourally very similar and have previously been shown to have low genetic distances at allozyme loci (Oudman et al, 1990;Kidd and Ritchie, 2000;Spooner, 2005).…”

“…A previous RAPD-based phylogeny also showed a genetic subdivision within the species, although this analysis was geographically limited (Ritchie et al, 1997). Partial Mantel tests and other analyses implied that most intraspecific variation originated through isolation in refugia, although environmental factors were found to influence body size (Kidd and Ritchie, 2000) and the pattern of mtDNA variation (Ritchie et al, 2001).…”

Evolution isolierter Teilpopulationen der Laubholz-Säbelschrecke Barbitistes serricauda (FABRICIUS 1798)

“…Zudem sind die Distanzmatrizen der RAPD-Analyse durch Bootstrapping nicht so gut gestützt wie die Matrizen, die aus den AFLP-Daten resultieren. Ritchie et al (1997) nicht darstellen. In der AFLP-Analyse setzen sich die zu Vergleichszwecken ebenfalls analysierten Tiere anderer Barbitistes-Arten deutlich von den B. serricauda-Populationen ab, obwohl nur wenige Individuen in der Analyse eingesetzt wurden.…”

“…Auch Saccheri et al (1998) Helversen & v. Helversen 1975a, b, Ritchie 1992, Stumpner & v. Helversen 1994. So untersuchten Ritchie et al (1997Ritchie et al ( , 2001) sowie Oudman et al (1990) …”

“…Obwohl die meist brachyptere M. roeselii unter bestimmten Bedingungen makroptere, flugfähige Individuen hervorbringt, somit also durchaus ein genetischer Austausch selbst zwischen separierten Populationen möglich ist, war die genetische Distanz zwischen Individuen der räumlich getrennten Populationen deutlich größer als die genetischen Unterschiede zwischen Tieren einzelner Teilpopulationen. Ritchie et al (1997Ritchie et al ( , 2001) sowie Oudman et al (1990) untersuchten die verwandtschaftlichen Beziehungen von Arten und Unterarten der Gattung Ephippiger (Steppensattelschrecken) in deren Hybridisierungszone im Süden Frankreichs. Die Unterarten ließen sich sowohl genetisch als auch morphologisch voneinander abgrenzen und wiesen Unterschiede beim Gesang der Männchen auf.…”