Bush-crickets with very special ears and songs – review of the East African Phaneropterinae genus Dioncomena Brunner von Wattenwyl, 1878, with notes on its biogeography and the description of new species

By

Hemp, Claudia
Montealegre-Z, Fernando
Woodrow, Charlie
Heller, Klaus-Gerhard

Type

Article

Date of Publication

2023

Original Publication

Deutsche entomologische Zeitschrift

Volume

70

Pages

221--259

Subjects

bioacoustics , Biogeography , Biology , Eastern arc mountains , Morphology , Phenology , Tanzania

Contributed by

Pensoft Publishers

Language

English

Published by

Berlin Nicolai'sche Verlags-Buchandlung 1881-

Identifiers

DOI: https://doi.org/10.3897/dez.70.100804

 

Abstract

This study focuses on the genus Dioncomena and its acoustics, particularly the unique songs produced by male Dioncomena that consist of several distinct elements in a fixed sequence, culminating in a coda that typically elicits a response from a receptive female. We also examine the inflated pronotal lobes, which we term prebullae, that are prominently developed in some Dioncomena species but not in others. We discuss the role of prebullae in the context of acoustic communication in Dioncomena and other related Phaneropterini genera that have similar lateral pronotal lobes. We found that prebullae size is correlated with habitat distribution, with larger prebullae occurring in isolated species while aggregation-prone species have smaller or less pronounced prebullae. Using micro-computer tomography we show sexual dimorphism in the 3D geometry of the acoustic tracheae, being larger in the male. Interestingly, the tracheae are coupled by a septum, like in field crickets, which suggests potential cross talk. We define three groups of Dioncomena based on altitude preferences, ecology, color patterns, and songs: the jagoi-, tanneri-, and ornata-groups. We describe the songs of several species, including newly identified species such as D. flavoviridis sp. nov., D. magombera sp. nov., D. ngurumontana sp. nov., D. sanje sp. nov., D. tanneri, D. versicolor sp. nov., and D. zernyi. We also provide information on the nymphs, development time, and mating behavior of various species reared in the laboratory, shedding light on their phenology and adaptations to their habitats.