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East Africa is a hotspot of biodiversity of many orthopteran taxa, including bushcrickets. Gonatoxia Karsch, 1889 species are fully alate Phaneropterinae, which are perfectly adapted to the foliage of forests. We examined five species using combined cytogenetic and molecular data to determine the inter- and intraspecific genetic diversity. The variation in the diploid number of chromosomes in males ranged from 2n = 28 + X0 and 26 + X0 to 2n = 6 + X0. Fluorescence in situ hybridization showed from one to many 18S rDNA loci as well as interstitial sequences, especially in G. helleri. 18S rDNA loci coincided with active NOR and C-banding patterns. The isolation of populations of the species explains differences in the number of chromosomes (G. maculata), chromosomal polymorphism and chromosomal heterozygosity (G. helleri). Our molecular phylogeny based on the COI locus supported the monophyly of the genus Gonatoxia and separateness of the five examined species in accordance with their morphological features and chromosome numbers as well as the species' distribution. [ABSTRACT FROM AUTHOR]

Acoustic communication is an essential part of the mate-finding system of many insects, e.g., ensiferan Orthoptera. In this group, the signals consist typically of relatively simple repetitive sound patterns produced for long times and used by the females for a phonotactic approach to the singing males. However, the situation can be different in duetting species where the females respond acoustically to the male. Here, we present data of the songs of 14 East African species of the duetting genus Eurycorypha. These songs are extremely diverse differing in many parameters and containing up to three different syllable types grouped into various echemes. In the duets between males and females, studied in 7 species, the females respond with latency times between 100 and 400 ms and are in some species able to react to different trigger syllables or also to the end of a series of syllables. The males often modify their songs after having heard a female response. Some of these modifications are also produced spontaneously. Similar elements are even found as integral part of the calling song in some species. We interpret these modifications aimed to protect a duet against eavesdropping rivals and thus as part of intrasexual selection. The evolution of the complicated song patterns may thus be driven by the interaction between female choice s.l. and male-male competition. [ABSTRACT FROM AUTHOR]

Although Eurycorypha is the most species-rich Phaneropterinae genus in Africa, little is known about the distribution and the ecology of the species. In this study data on distribution, ecology, song and on chromosomes of some East African species are provided. The nymphs of some species are shown, famous for their ant-like appearance and behaviour. The male of E. punctipennis Chopard and three species of Eurycorypha are newly described. These are E. resonans n. sp. and E. combretoides n. sp. occurring in different habitats on Mount Kilimanjaro, and E. conclusa n. sp from forest habitats along the Tanzanian coast. Bioacoustically, the four recorded species are unusually divers, presenting non-resonant and resonant songs. As four Eurycorypha species occur syntopically on geological young Mount Kilimanjaro, the biogeographical pattern and possible speciation mechanisms in the genus Eurycorypha are discussed in context of the climatical history of eastern Africa. [ABSTRACT FROM AUTHOR]