Review of the Plangia graminea (Serville) complex and the description of new Plangia species from East Africa (Orthoptera: Phaneropteridae, Phaneropterinae) with data on habitat, bioacoustics, and chromosomes

Abstract

The Plangia graminea complex is partly reviewed and two new species of Plangia are described, Plangia multimaculata n. sp. from savanna habitats and Plangia satiscaerulea n. sp. from the submontane zones in northern Tanzania. Plangia compressa (Walker 1869) is synonymized with P. graminea (Serville, 1838). Data on habitat, bioacoustics, and chromosomes are provided. Both analyzed Plangia species showed the same chromosomal number. Compared to other investigated African Phaneropterinae, Plangia had a reduced chromosome number and thus shows a derived condition in its genome. The sex chromosomes differed morphologically in both investigated species of Plangia suggesting different mechanisms leading to these differences. Niche specialization and the male calling song are discussed as drivers for speciation in fully alate and thus mobile taxa.

Comparative analysis of chromosomes in the Palaearctic bush-crickets of tribe Pholidopterini (Orthoptera, Tettigoniinae)

“…Warchałowska-Śliwa et al 2013b) and African (Hemp et al 2010b, 2013, 2015a) Phaneropterinae likewise in European Saginae (Warchałowska-Śliwa et al 2009) and Bradyporinae (Warchałowska-Śliwa et al 2013a), as well as in some grasshoppers (e.g. Cabral-de-Mello et al 2011b).…”

Paraplangia sinespeculo, a new genus and species of bush-cricket, with notes on its biology and a key to the genera of Phaneropterinae (Orthoptera: Tettigonioidea) from Madagascar

“…They mated in the morning (about 9:00-10:00; they were placed together the evening before, but did not mate) with mating durations of a few minutes and transferred spermatophores of 130 and 151 mg (mean of male loss and female gain), thus about 12% of the male body mass. They were slightly smaller than in Plangia multimaculata (17%; Hemp et al 2015). Both spermatophylaces showed relatively irregularly formed central parts protruding anteriorly, in addition to the symmetrical lateral basal parts (Fig.…”

“…Gorochov (1988) considered this group of short-winged species as a sister group to all other world-wide distributed Conocephalinae. However, in a Paraplangia sinespeculo, a new genus and species of bush-cricket, with notes on its biology and a key to the genera of Phaneropterinae (Orthoptera: Tettigonioidea) from Madagascar recent molecular study (Hemp et al 2015) the Euconchophorini representative appeared basally to the studied Agraeciini from Africa, India and Australia, but within Conocephalinae. In any case, a member of this Agraeciini/Euconchophorini-complex seems to have arrived in Madagascar relatively long ago.…”

The metabolic costs of sexual signalling in the chirping katydidPlangia graminea(Serville) (Orthoptera: Tettigoniidae) are context dependent: cumulative costs add up fast

“…In the fourth species, Bailey et al (1993) focused on the energetic costs of calling in the chirping katydid, Requena verticalis (Listroscelidinae). The present study aims to add to Bailey et al (1993)'s findings, and the global database across taxa, by investigating the metabolic cost of calling in an unstudied sub-Saharan katydid, Plangia graminea (Serville 1838) (Phaneropterinae) (Hemp et al, 2015), which also produce chirping calls. We predict that, as in the case of the other orthopterans, there is a cost associated with calling; but, as found with R. verticalis, the cost is likely to be relatively low compared with the costs observed in trilling katydids.…”