This study updates the known distribution of Rhombodera latipronotum Zhang, 1990, a mantis species previously documented only in the Yunnan province of China. New findings confirm its presence in the Guangxi autonomous region and the Indo-Chinese states of Laos and Vietnam. The research incorporates both direct analysis of collected specimens and data gathered from citizen-science platforms. These methodologies have allowed for a redefinition of the species’ range in Southeast Asia and have provided new insights into its external morphology and intraspecific variability. Due to its recent description and the limited availability of scientific literature, R. latipronotum remains poorly understood. This study overcomes these limitations by providing the first detailed description of both sexes, highlighting the intraspecific variability of the specimens, and discussing the potential existence of distinct populations within the species. The research also highlights the immense biodiversity within the surveyed regions, emphasizing the need for extensive exploration to fully catalogue the species of the order Mantodea. Understanding the distribution and ecological roles of these mantids is essential for their conservation. The study’s findings contribute to a deeper knowledge of R. latipronotum and underscore the importance of continued biological surveys and conservation efforts in these biodiverse yet underexplored areas of Southeast Asia.

Citizen science, distribution update, Hierodulini, Indochina, shield mantis

Rhombodera Burmeister, 1838 is a genus of praying mantises belonging to the family Mantidae, subfamily Hierodulinae, and tribe Hierodulini. They are known by the common name “Asian shield mantids” because of a feature shared by all species included in this genus: the presence of more or less pronounced lateral pronotal expansions that make the first thoracic segment resemble a shield. In most species, the dorsal part of this shield is green and helps the insect camouflage itself, even hiding its forelimbs when they are folded, while the ventral part is brightly colored, and the insect displays it during the deimatic poses it performs when it has already been spotted by a predator and can no longer resort to cryptic camouflage (Wieland 2013).

Other typical features include straight or only slightly curved vertex, head generally wider than long, well-developed flight organs in both sexes but longer in the male, which can make flights of considerable distances. The tegminae are green or brown, with opaque costal and/or discoidal area having a whitish stigma with or without dark outlines; hind wings are hyaline or partially shaded with bright colors, especially in the costal area. Fore femora with 4 internal and 4 external spines, and claw groove located proximally in the middle of the limb; fore tibiae with 9–11 external spines; metatarsi of the hind legs about as long as the remaining segments put together; supra-anal plate transverse and rounded at the cerci (Ehrmann 2002). The genus currently includes 30 species (Anderson 2024) spread widely in mainland and insular Asia in countries such as Cambodia, China, India, Indonesia, Japan, Laos, Malaysia, Myanmar, Nepal, Papua New Guinea, Philippine Islands, Solomon Islands, Sri Lanka, Thailand, Timor, and Vietnam (Patel and Singh 2016). However, the taxonomy and phylogeny of the Hierodulini are not yet well defined, and synonyms in this large group of mantids are frequently rediscussed and updated, especially between the genera Hierodula Burmeister, 1838, Rhombodera Burmeister, 1838, Titanodula Vermeersch, 2020, and Sphodromantis Stål, 1871 (Vermeersch 2020, Vermeersch and Unnahachote 2020). For this reason, it is very likely that the number of species will change again, and some actual members of the genus Rhombodera will be transferred into new genera, as happened in the past.

The species Rhombodera latipronotum Zhang, 1990 was described in 1990 by Zhang as endemic to southern China, specifically the forested areas of Yunnan province, one of the country’s richest places for mantids (and insects in general) and considered an intersection of three different biodiversity hotspots: the Indo-Burma region, the mountains of Southwest China, and the eastern Himalayas region (Yu et al. 2022). The specific epithet latipronotum is derived from the union of the Latin adjective lātus, lată, latum, meaning “broad” or “wide,” and the noun pronotum, which precisely denotes the dorsal part of the first thoracic segment of the insects. Indeed, the distinguishing characteristic of this mantis is the width of the pronotum, which is wider than that of many other Rhombodera species and sometimes exceeding 20 mm in adult females (Liu et al. 2021). The description of this new species occurred relatively recently, and several authors have pointed out how difficult it is to collect specimens for examination. The discoverer of the species based his original description on a single male specimen designated as the holotype. Subsequently, other mantis enthusiasts attempted to collect specimens of R. latipronotum at the type locality using light traps. It was found that only males were attracted to the traps, while females were much more difficult to catch (Xiaoyu 2012).

Due to the aforementioned taxonomic uncertainties, identification of specimens of this species is not always possible, partly due to the often incomplete scientific literature on this insect. In more recent years, the increasing interest in mantids around the world, including their taxonomy and amateur breeding (Battiston et al. 2022), has prompted many citizens to take a critical look at the mantises in their areas, taking photos of them and uploading them to citizen science platforms. Thanks to their fieldwork, scholars have made numerous discoveries about the external morphology of still little-known mantids and that the distributions given in scientific articles do not always correspond to the truth, as they might be obtained from outdated or incomplete data (Battiston et al. 2021). This article aimed to update the geographic distribution of R. latipronotum and provide a redescription of its external morphology. The implications of updating R. latipronotum’s distribution range, particularly on the mantid fauna of Southeast Asia, are also discussed.

The study included the collection and examination of specimens kept in entomological collections as well as the observations of citizen scientists from different Southeast Asian countries who uploaded photographs to platforms such as iNaturalist and the Global Biodiversity Information Facility (GBIF) or on social networks. On Facebook, various reports were collected through insect identification groups, and on Instagram, through the creation of the ‘Mondo delle Mantidi’ (in Italian means “World of Mantids”) network, the author of the study was able to collect further reports from ordinary citizens through the chat rooms. For each insect photo, users were asked for the exact location where the specimen was found and relevant environmental information, such as whether the location was urban or suburban. All citizens’ reports were compared with specimens in the author’s entomological collection, producing, in tandem with photographs taken with a Nikon Coolpix B500 and processed with the Adobe Photoshop program, an accurate description of adults of both sexes. The terminology used follows Brannoch et al. (2017), and the preparation of the genitalia follows Battiston et al. (2010). Distribution maps were made using QGIS 3.34 Prizen software.

The report of R. latipronotum in new Asian localities represents a significant advancement in the field of biogeography and in the taxonomy of praying mantids. This discovery expands our understanding of the geographical distribution of this species, suggesting that it has a wider habitat range and greater adaptability than previously thought. Reports of R. latipronotum in new regions such as Laos, Vietnam, and Guangxi indicate that this mantis species is capable of adapting to a variety of environments, from the tropical climate of Southeast Asia to the specific conditions of the Guangxi region in China. This suggests that it possesses considerable ecological plasticity, allowing it to colonize a variety of ecological niches.

The ability of R. latipronotum to colonize new habitats demonstrates considerable ecological adaptability. This species is able to exploit a wide range of food resources and adapt to different microhabitats. Future ecological studies should focus on analyzing the specific environmental requirements of the species and the adaptation strategies that allow it to thrive in different environments. The introduction of this species into new ecosystems can influence the dynamics of local insect communities; being an efficient predator, its presence could alter prey populations and compete with other predators. Thus, it is essential to study the ecological interactions of R. latipronotum with other species to understand the ecological impact of its geographic expansion. Additionally, the possibility that the species’ expansion is partly due to accidental or deliberate introductions by humans cannot be ruled out given the increasing movement of goods and people between these regions (Battiston et al. 2018; Battiston et al. 2020).

The new populations of R. latipronotum in Laos, Vietnam, and Guangxi also require special attention for conservation (Wikramanayake et al. 2002). If these populations are found in threatened or fragmented habitats, they may require specific protection measures. Knowledge of the extensive distribution of the species may inform more targeted and effective conservation strategies, ensuring the protection of critical habitats and vulnerable populations.

Similarly, the new reports of R. Latipronotum provide valuable insights for biogeographical research (Zhou and Shen 1992). The presence of the species in different regions may suggest ancient connections between now-disjointed habitats or processes of natural dispersion. Future studies should investigate the mechanisms of this species’ dispersion, including the biotic and abiotic factors that promote its spread and stabilization in new territories. Understanding the evolutionary history and dispersion patterns of R. latipronotum can be deepened through comparative studies with other species of the genus Rhombodera. This could reveal information about dispersion modes, such as migration through ecological corridors or colonization of new habitats in response to climate and environmental changes.

The results of this study represent a significant expansion of our knowledge of the distribution of this species, highlighting the importance of continuing exploration and documentation of biodiversity, especially in poorly known regions. The presence of the species in new habitats underscores the dynamic nature of biodiversity and the need for continuous monitoring to adapt conservation and species management strategies. The expansion of the geographical distribution of R. latipronotum offers new opportunities for ecological and biogeographical research, contributing to a better understanding of ecological interactions and evolutionary dynamics. Future studies should focus on a detailed analysis of the ecological requirements of the species, its interactions with other species, and implications for conservation, ensuring the protection and sustainability of R. latipronotum populations throughout its new geographical range.

In this study, the descriptions and morphological knowledge of R. latipronotum were updated, expanding our understanding of this species within the Rhombodera genus. Previously undescribed morphological features, such as the structure of the forewings and the presence of intraspecific variability of the pronotum, were revealed. These observations further distinguish R. latipronotum from congeneric species and provide new insights for the taxonomic revision of the group. Additionally, the integration of advanced imaging techniques allowed us to document key morphological structures with greater precision, offering a detailed reference for future comparative studies. These findings both enrich the morphological description of this species and suggest the need for a reassessment of phylogenetic relationships within the genus, highlighting the importance of detailed morphological analysis for accurate species identification.

The author would like to thank Evgeny Shcherbakov (Department of Entomology, Lomonosov Moscow State University, Russia) for his valuable support and advice regarding the identification of the specimens examined. Special thanks also go to the observers on the iNaturalist platform who helped collect the data for this article. The author would also like to thank the anonymous reviewers and the Orthopterists’ Society for their support in this manuscript.

The author declares that they have no conflict of interest.