Secondary structure and phylogenetic analysis of the internal transcribed spacers 1 and 2 of bush crickets (Orthoptera: Tettigoniidae: Barbitistini)

A taxonomic revision of the Palaearctic genus Roeseliana (Orthoptera: Tettigoniidae: Tettigoniinae: Platycleidini): a case of ongoing Mediterranean speciation

The genus Roeseliana presently includes 10 specific or subspecific taxa, but following different authors some of them are considered synonyms. However, the authors who have treated these taxa often did not agree with the synonymies, in particular, concerning some taxa, such as R. fedtschenkoi (Saussure, 1874) and R. roeselii (Hagenbach, 1822). The present authors examined hundreds of specimens of different taxa, for the first time were able to obtain the translation from the Russian of the description of R. fedtschenkoi, compared the main morphological characters used to discriminate different taxa, biometrics, bioacoustics and genetics of some taxa. This allowed them to conclude that it is possible to recognize the following taxa: 1) Roeseliana roeselii (Hagenbach, 1822) widespread in the Palaearctic Region and imported in North America; 2) Roeseliana fedtschenkoi (Saussure, 1874) in Uzbekistan and Turkmenistan; 3) Roeseliana pylnovi (Uvarov, 1924) in the Caucasian region; 4) Roeseliana bispina (Bolívar, 1899) in Turkey; 5) Roeseliana azami (Finot, 1892) from the Mediterranean France through Italian peninsula (formerly R. azami minor Nadig, 1961); 6) R. ambitiosa (Uvarov, 1924) on the Balkan peninsula; 7) Roeseliana n. sp. Lemonnier-Darcemont & Darcemont, (in press) on Epirus (Greece and Albania); 8) Roeseliana brunneri Ramme 1951 in north east Italy (Veneto, Friuli and Po Valley); 9) Roeseliana oporina (Bolívar, 1887) in Spain.

A review of Eupholidoptera (Orthoptera, Tettigoniidae) from Crete, Gavdos, Gavdopoula, and Andikithira

Being nocturnal, hiding in prickly bushes and shrubs during the day, Eupholidoptera species in Crete and its neighbouring islands are easily overlooked, and until now our knowledge about their distribution was based on some thirty sightings across 11 species. In this paper results are presented of a study of Eupholidoptera specimens collected between 1987 and 2020 by hand-catches and pitfall and fermenting traps on the Greek islands of Crete, Gavdos, Gavdopoula, and Andikithira. Diagnostic features of all known species are presented and illustrated with stacked images. An updated key to all species is provided. Eupholidoptera francisae Tilmans & Odé, sp. nov. from Andikithira and southwestern Crete and Eupholidoptera marietheresae Willemse & Kotitsa, sp. nov. from Mt. Dikti are described. Female E. cretica, E. gemellata, and E. mariannae are described, and the female of E. astyla is redescribed. Bioacoustics for E. francisae Tilmans & Odé, sp. nov., E. giuliae, and E. jacquelinae are presented for the first time. Eupholidoptera smyrnensis is reported for the first time from Crete. A substantial amount of new distribution data for Eupholidoptera species on Crete is presented. The current distribution pattern and first analyses of phylogeny based on molecular data of Eupholidoptera species on Crete are discussed in relation to paleogeographical events.

A taxonomic outline of the Poecilimon affinis complex (Orthoptera) using the geometric morphometric approach

The genus Poecilimon contains 145 species, widely distributed in the Palaearctic, among which the Poecilimon ornatus group has the greatest diversity in the Balkans. Despite several revisions of the genus, the systematics of the species group, and in particular, of the taxa associated with the species Poecilimon affinis, is still unsolved. Due to morphological similarity, P. affinis with its subspecies, P. nonveilleri and P. pseudornatus form the Poecilimon affinis complex. The aim of this study is to test the hypotheses of an outlined species complex, namely the P. affinis complex, within the P. ornatus group using morphological data. Geometric analysis was conducted to explore variation in the structure of the male tegmen, ovipositor, male cercus, and male pronotum. The number of teeth and stridulatory file measurements provided additional information on morphological variation within the complex. A phylogenetic tree based on the cytochrome c oxidase subunit I gene (COI) was used for comparison with the morphological data. Canonical variate analysis showed that male tegmen and male cercus are good morphostructures to distinguish the taxa belonging to the P. affinis complex from other species in the P. ornatus group. This may confirm our assumption for the designation of the P. affinis complex. The results of the principal component analysis of stridulatory file measurements, molecular data, and CVA of the ovipositor suggest adding two additional species to the complex: P. ornatus and P. hoelzeli.

Impact of low sperm competition on male reproductive trait allometries in a bush-cricket

Background

Studying reproductive trait allometries can help to understand optimal male investment strategies under sexual selection. In promiscuous mating systems, studies across several taxa suggest that testes allometry is usually positive, presumably due to strong selection on sperm numbers through intense sperm competition. Here, we investigated testes allometry in a bush-cricket species, Metaplastes ornatus, in which females mate promiscuously, but where sperm removal behaviour by males likely drastically reduces realised sperm competition level.

Results

As hypothesised, we found evidence for negative testes allometry and hence a fundamentally different male investment strategy compared to species under intense sperm competition. In addition, the mean relative testes size of M. ornatus was small compared to other species of bush-crickets. Surprisingly, the spermatophore gland, a potential alternative trait that males could invest in instead of testes, also did not show positive allometry, but was approximately isometric. We further observed the expected pattern of negative allometry for the male morphological structure responsible for sperm removal in this species, the subgenital plate, supporting the one-size-fits-all hypothesis for intromittent genitalia.

Conclusion

Our findings suggest that the evolution of sperm removal behaviour in M. ornatus was a key adaptation for avoiding sperm competition, with important consequences for reproductive trait allometries. Nevertheless, they also imply that it does not pay for larger males to invest disproportionately in nuptial gift production in this species.

High-speed duetting - latency times of the female acoustic response within the bush-cricket genera Leptophyes and Andreiniimon (Orthoptera, Phaneropteridae)

To find a mate, male and female bush-crickets of the family Phaneropteridae typically engage in duets. The male sings and the female responds. For mutual recognition, the amplitude pattern of the male song and the species-specific timing of the female response have been shown to be very important. In the seven studied species, belonging to the genera Leptophyes and Andreiniimon, these duets are extremely fast and nearly completely in the ultrasonic range. The females produce very short sounds by fast closing movements of the tegmina. They respond with species-specific delays of 20 to 150 ms after the beginning of the male song. The different latency times are probably not important for species recognition, since in sympatric species they are quite similar.

Molecular and classical chromosomal techniques reveal diversity in bushcricket genera of Barbitistini (Orthoptera)

The cytogenetic characteristics of 17 species of bushcricket belonging to eight genera of the tribe Barbitistini were examined by fluorescence in situ hybridization with 18S rDNA and (TTAGGn) telomeric as probes and by C-banding, silver, and fluorochrome staining. These markers were used to understand chromosomal organization and evolutionary relationships between genera or species within the same genus. The number of 18S rDNA clusters per haploid genome that co-localized with active nucleolus organizer regions (NORs) ranged from one to five, with the most common pattern being the presence of one NOR-bearing chromosome. This ribosomal cistron was preferentially located in the paracentromeric region of autosomes and very rarely in the sex chromosome. The results demonstrated coincidence between the localization of major ribosomal genes and active NORs and the position of C-band and GC-rich regions. The rDNA/NOR distribution and the composition of chromosome heterochromatin proved to be good cytogenetic markers for distinguishing species and phylogenetic lines and for understanding the genomic differentiation and evolution of Barbitistini. A comparison of cytogenetic and morphological or behavioral traits suggests that morphological and behavioral specialization in this group was not followed by major karyotype modification (except for Leptophyes). However, the occurrence and distribution of different repetitive DNA sites tends to vary among the taxa.