|Hemp, C; Heller, K-G; Warchalowska-Sliwa, E; Grzywacz, B; Hemp, A: Biogeography, ecology, acoustics and chromosomes of the East African genus Afroanthracites Hemp & Ingrisch (Orthoptera, Tettigoniidae, Conocephalinae, Agraeciini) with the description of new species., Organisms Diversity & Evolution, 15, 351-368 (2015), doi:10.1007/s13127-014-0194-2|
The flightless Agraeciini genus Afroanthracites, a genus restricted to East Africa, is reviewed and two new species are described. Exemplary for the genus Afroanthracites, the ecological niche of Afroanthracites montium from Mt Kilimanjaro is defined. A. montium occupies habitats in humid and perhumid conditions and thus shows a broad altitudinal range (1250–2700 m). Concerning the acoustic communication, it is remarkable that within the micropterous genus a trend to low carrier frequencies is observed combined with the evolution of larger stridulatory organs (mirror; resonating part of tegmen). This trend starts with species using the same ultrasonic frequencies as a brachypterous out-group and ends with species presenting clearly audible songs. Cytogenetic data are given for five Afroanthracites and one Afroagraecia species. Differences in chromosome numbers Afroanthracites 2n=29 and Afroagraecia 2n=27 as well as a number of major rDNA clusters (one and two, respectively) are probably useful markers to separate both genera. It is discussed whether the African species evolved from a species with a presumably derived karyotype (e.g. 27 or 29 chromosomes) or if the proposed reduction of chromosome number occurred independently in Africa, Asia and Australia. The data set suggests that the African Agraeciini is of monophyletic origin, with a common ancestor of Afroagraecia and Afroanthracites in Africa. The Afroanthracites species can be divided into three groups on base of their morphology and colour pattern. Species of adjacent areas are morphologically sister groups. The most derived forms as seen in their morphology and acoustics are found in the West Usambara Mountains, part of the geologically old Eastern Arc Mountains.