# Integrative Taxonomy Revealed Cryptic Diversity in the West African Grasshopper Genus Serpusia Karsch, 1891 (Orthoptera: Catantopinae)

## TL;DR

This study reveals hidden species diversity in the African grasshopper genus Serpusia using DNA and morphology, leading to the discovery of new species and a new genus.

## Contribution

The study combines molecular and morphological data to uncover cryptic diversity in Serpusia and establish a new genus, Paraserpusia.

## Key findings

- Serpusia contains five species, four newly described, with one previously known species split into six lineages.
- A new genus, Paraserpusia, is established to accommodate genetically distinct S. succursor and its hidden species.
- Molecular and morphological data confirm distinct clades and support the taxonomic revisions.

## Abstract

Serpusia is a wingless grasshopper genus that is restricted to African Rainforests. Serpusia species exhibit largely external resemblance to species of several related genera, including Aresceutica, Pseudophialosphera, Segellia, Auloserpusia, Pteropera, Coenona, Serpusilla, and Veseyacris. The taxonomic status of Serpusia remains challenging, and its classification is unstable. Despite the alarming ongoing habitat loss in the African Rainforests, this genus has never been revised using modern molecular techniques. In this study, we used both morphological and molecular approaches to provide insights into the current diversity of this genus. We sequenced two mitochondrial markers (COI-5P and 16S rDNA) and constructed the phylogenetic relationships among species of Serpusia and closely related genera. It appeared that Serpusia is more diverse than what is currently known, encompassing five species, four of which we described in this study. In addition, one of the previously known species of Serpusia, the so-called S. succursor, is genetically very distinct from the true Serpusia and also encompasses hidden species. We then established a new genus, Paraserpusia, to accommodate S. succursor and its hidden species, which were formally described in this study. Overall, this study highlights the importance of combining molecular and morphological data to uncover and formally describe previously underestimated groups.

Background/Objectives: Despite their ecological significance, DNA barcoding data for African rainforest Orthoptera remain underrepresented globally, limiting progress in species discovery, biodiversity assessment, and conservation. This study aimed to generate molecular data for morphologically identified Serpusia Karsch, 1891 species to evaluate their taxonomic status. Methods: Specimens were collected from multiple sites in Cameroon and analyzed using DNA barcoding with COI-5P and 16S rDNA markers. Species delimitation was performed with Automatic Barcode Gap Discovery, and phylogenetic relationships were inferred using Maximum Likelihood and Bayesian Inference. Additionally, external morphology and the male phallic complex were examined. Results: Molecular analyses delineated 19 MOTUs, five corresponding to Serpusia opacula, seven to Serpusia succursor and the remainder to outgroups. Similarity-based assignments matched these MOTUs to 19 BINs. Phylogenetic reconstruction revealed S. opacula and S. succursor as two genetically distinct clades, with the S. opacula group more closely related to Aresceutica Karsch, 1896 than to the S. succursor group. Accordingly, we established a new genus, Paraserpusia gen. nov., to accommodate S. succursor. Within the S. opacula group, five species are recognized: one previously described (S. opacula) and four new species (S. kennei sp. nov., S. missoupi sp. nov., S. seinoi sp. nov., and S. verhaaghi sp. nov.). The former S. succursor, now Paraserpusia succursor, is divided into six well-supported lineages, five of which are formally described here (P. hoeferi sp. nov., P. husemanni sp. nov., P. kekeunoui sp. nov., P. tamessei sp. nov., and P. tindoi sp. nov.). A haplotype network based on COI-5P sequences corroborates three major clades corresponding to the S. opacula group, the S. succursor group, and Aresceutica. Diagnostic morphological differences between Serpusia and Paraserpusia are consistently supported across characters. Conclusions: This integrative approach reveals substantial hidden diversity within Serpusia and highlights the importance of combining molecular and morphological data to uncover and formally describe previously overlooked taxa.