Revision of the cricket genus Nisitrus Saussure (Orthoptera: Gryllidae: Eneopterinae) and descriptions of five new species

Ming Kai Tan,Rodzay Bin Haji Abdul Wahab,Tony Robillard,Razy Japir,Authur Y.C Chung

doi:10.5852/ejt.2021.761.1449

Abstract

Nisitrus Saussure, 1878 is a diurnal and monophyletic group of eneopterine crickets found in parts of Southeast Asia. Species often have vivid colourations which make them charismatic photograph subjects among macro photographers. However, their taxonomy has not been revised since their original descriptions, whereas there are also species awaiting to be discovered and described. A synoptic revision is therefore needed prior to studying the phylogenetic relationships of the genus, and before undertaking more precise studies on biogeography and evolution of traits. By holistically incorporating information about general morphology, male and female genitalia, and bioacoustics, we revise the taxonomy of these crickets and recognise 10 valid species of Nisitrus. Five new species are described: N. crucius Robillard & Tan sp. nov. from Borneo; N. danum Robillard & Tan sp. nov. from Borneo; N. hughtani Robillard & Tan sp. nov. from Sumatra; N. malaya Robillard & Tan sp. nov. from Malay Peninsula; and N. rindu Robillard & Tan sp. nov. from Borneo. We redescribe N. brunnerianus and N. insignis; describe the calls of N. malaya sp. nov., N. musicus and N. vittatus. We consider N. sumatrensis as a junior synonym of N. insignis; and N. marginata as a junior synonym of N. vittatus. Nisitrus hyalinus requires further revision. We also consider N. maculosus as a dubious name.

Highlights

Nisitrus Saussure, 1878 is a monophyletic and morphologically unique group of common eneopterine crickets distributed in Southeast Asia (Fig. 1)
Male genitalia can be variable within species of Nisitrus, partly due to their more membranous nature, which can be deformed due to preservation or state of specimens
Female genitalia can be more useful than male genitalia in some instances, as for example to differentiate N. vittatus and N. malaya sp. nov

Summary

Introduction

Nisitrus Saussure, 1878 is a monophyletic and morphologically unique group of common eneopterine crickets distributed in Southeast Asia (Fig. 1). It belongs to the tribe Nisitrini Robillard, 2004 along with the apterous genus Paranisitra Chopard, 1925, which was taxonomically reviewed in a recent study (Baroga-Barbecho et al 2019). Males can be heard calling among vegetation throughout daytime (Fig. 2). As these crickets usually stay on the foliage, they tend to feed on fresh leaves and flowers (Tan et al 2017). They can be widely distributed and abundant locally

Methods

Results

Conclusion