Distribution patterns of Chinese Cixiidae (Hemiptera, Fulgoroidea), highlight their high endemic diversity

Abstract Background Cixiidae are small strictly phytophagous hemipteran insects worldwide distributed. Ecology and systematics of Chinese fauna remains poorly investigated. For instance, does their distribution follows the patterns of biogeogaphical distribution established for their host plants or other related-taxa because they are all obligatory phytophagous taxa? Do they follow the usual distributional Chinese realms and boundaries already recognized? Which zoogeographical Chinese regions and connections between them do they depict. To investigate these issues, we provide here a referenced and comprehensive checklist of the 250 cixiid species currently reported from China (77 new records), with their precise distribution at the regional level. In the 8 Chinese main zoogeographical regions usually recognized and 2 adjacent areas, we analyzed further their diversity at the tribal, generic, and specific levels using a non-metric multidimensional scaling and an unweighted pairwise group analysis using an arithmetic mean cluster analyses. The observed distribution patterns shown that an intercalary Sino-Japanese realm is recognisable between the Palaearctic and Oriental realms. At the regional level, the South China region clusters more closely with the Southwest, Central and North China regions. Taiwan, clearly separated from the South China region and mainland China, is more closely related to the Qinghai-Tibet region and Indochina countries. Although Central and South China regions remain close to each other, the Qinghai-Tibet region appears singularly different. New information An updated checklist of the 250 Cixiidae species, known to occur in China and counting for 10% of the Chinese planthopper fauna, is presented based on literature, recent collections, and museum records. More than 400 records distributed among the 28 provinces and 8 regions in China are extensively provided, including 77 new records. Of these, more than 80% of the species (205 species, 82%) have been only reported from China, and most of them are endemic species, which could reflects the great diversity degree of the Chinese regions and local biotypes highlights the uniqueness of this fauna. These species are found in 8 Chinese zoogeographical regions: The Taiwan region is the most diversified with 161 species and the highest rate of endemic species (69.57%), followed by South China (78 species, 17.95%), Central China (60 species, 33.33%), Southwest China (43 species, 39.53%), North China (29 species, 34.48%), Qinghai-Tibet region (10 species, 20%), Northeast China (8 species, 12.5%), and 5 species found in the Inner Mongolia-Xinjiang region that are not endemic ones. Endemism was analyzed for each region and repeated for species distribution patterns across them, 9 being bi-regionally and tri-regionally distributed. The South China-Taiwan pattern is the most richest one, followed by the Central-South China-Taiwan pattern. Semonini and Pentastirini tribes are widespread among all the zoological regions, representing respectively 21.20% and 17.20% of all the species, while Cixiini being is the most common tribe with 45.20%, remains absent from the North-Eastern China region. Andini with only 5.20% of the species is distributed in the Sino-Japanese - Oriental Region; Eucarpini (6.40%) and Borysthenini (2.00%) are mainly concentrated in the south of the Qingling Mountain-Huai River. The remaining four tribes, Bennini (0.40%), Briixini (0.80%), Oecleini (1.20%) and Stenophlepsiini (0.40%) are relatively rare and restricted to Taiwan. At the generic level, Kuvera (7.2%) is the most widely distributed genus in China while Cixius, Betacixius, Kuvera, Oecleopsis and Andes are the more diversified. One genus (Oliparisca) is distributed only in the Tibet region, while 10 genera are distributed only in the Taiwan region. In addition, nearly half of the genera (16 genera, 48.48%) are distributed south of the Palearctic/Oriental boundary. A non-metric multidimensional scaling and an unweighted pairwise group method analysis using arithmetic mean clustering based on the Jaccard similarity coefficient matrix support a Palaearctic/Sino-Japanese boundary and a South China region closer to the Southwest, Central and North China regions. The Taiwan region appears clearly separated from the South China region and to mainland China, and more closely related to the Qinghai-Tibet region and Indochina countries. The Central and South China regions appear close to each other, but the Qinghai-Tibet region is singularly isolated.


Introduction
China covers an area of 9,634,057 km , encompassing a area of entire Europe, and spans nearly 50 degrees of latitude from north to south, and more than 60 degrees of longitude from east to west in a world-renowned monsoon region (National Bureau of Statistics of the People's Republic of China, http://data.stats.gov.cn). Most regions have cold, dry winters and warm, rainy summers, but in combination with the varying topography and terrain conditions, the climate is actually very complex and locally diverse with a wide variety of temperature zones and precipitation gradients (Ren and Wen 2011). Most regions are located in the temperate zone (semi-tropical, warm, mid-range, and cold-temperatures). A small portion of the country is in the tropics and plateau climate zone (the Qinghai-Tibet plateau temperate zone), and northern regions are close to the boreal zone . Annual precipitation decreases from the rain-forest of the southeast coast to the Gobi Desert in the northwestern interior ). An arid humidity zone covers about 31% of the land area (mainly in northwest China). A semi-arid zone covers 22%, a semi-humid zone covers 15%, and the humid zone (32%) is located primarily in the southeast of China . Geological complexity of China is also significant, particularly with the uplift of the Qinhai-Tibet Plateau, which occurred in the middle of the Eocene era (45-38 Ma) . When this complexity is combined with the monsoonal climate evolution, it has created strongly diversified biotopes, isolated by biogeographical barriers that manage dispersal pathways for species, providing new ecological niches, which has driven the recent evolution of plants and animal diversity (Favre et al. 2015. From a biogeographical point of view, China is usually divided in two parts, the Palearctic realm in the north, and the Oriental one in the south (Sclater 1858, Wallace 1876, Morrone 2015, . From a zoological perspective, Holt et al. (2013) recently recognized an additional Sino-Japanese realm ranging from west of Tibet to the east of the Japanese archipelago standing between them. Accordingly, three main biogeographical lines cross China ( Fig.1): the Palaearctic/Sino-Japanese boundary at about 40-41N, the Palearctic/ Oriental line that follows the Qingling Mountain-Huai River, around 32-34N, and the Sino-Japanese/Oriental boundary at 24-25N in Southeastern China.
The family Cixiidae Spinola, 1839 (Hemiptera: Fulgoromorpha), is a numerous and diverse taxon with a world-wide distribution (Holzinger et al. 2002, Bourgoin 2021. It comprises 18.6% of the currently known planthopper species (Bourgoin 2021), and is the largest family of the group. Classical taxonomy has divided the Cixiidae into 3 subfamilies: Borystheninae Emeljanov, 1989, Bothriocerinae Muir, 1923and Cixiinae Spinola, 1839(Holzinger et al. 2002. However, recent phylogenetical analyses have shown that these divisions remain artificial and three main lineages should better reflect of evolution of the family: an oecleinian lineage (including Bothriocerini), a cixiinian lineage and a pentastirinian lineage (including Borysthenini) (Luo et al. 2021). Therefore, without including the fossil taxa, Cixiidae are currently divided into 18 tribes, 250 genera, and 2600 species (Bourgoin 2021).
Although the Cixiidae are one of the larger planthopper families, little is known about their ecology, distribution and host plants. In China, knowledge of this fauna is still fragmented and an overall comprehensive study is lacking. The first contribution was by Melichar (1902) who described 2 genera with 5 species from western China. Matsumura (1914) published 'Die Cixiinen Japans', describing 14 genera and 30 species, mostly from Taiwan. Kato (1932) focused on Northeastern China taxa, and published one new species. The first checklist of Cixiidae from the China mainland was provided by Hu (1935), who listed 11 species in 5 genera, which was updated by Metcalf (1936) in his 'Catalogue of the Homoptera'. Since then, many new species have been added. Jacobi (1944) reported 5 new species from the Fujian province. Fennah (1956) added 6 genera and 17 species from South China. Hori (1982) described 3 new Betacixius species from Taiwan. Chou et al. (1985) described 7 species in 4 genera in his "Economic Insect Fauna of China (Fulgoromorpha)". Tsaur provided a series of important contributions to the fauna from Taiwan, describing 155 species in 20 genera (Tsaur and Lee 1987, Tsaur et al. 1988, Tsaur 1989a, Tsaur 1989b, Tsaur 1990a, Tsaur 1990b, Tsaur et al. 1991a, Tsaur et al. 1991b, Tsaur and Hsu 2003, Tsaur 2009). Since then, several papers describing new recent taxonomic discoveries have been published (Wang 1991, Wang 1992, Huang 1995, Hua 2000, Liang 2001, Liang 2005a, Liang 2005b, Guo and Wang 2007, Guo et al. 2009, Guo and Feng 2010, Zhang and Chen 2011a, Zhang and Chen 2011b, Zhang and Chen 2013a, Zhang and Chen 2013b, Ren et al. 2014, Xing and Chen 2014, Bai et al. 2015, Zhi et al. 2017, Zhi et al. 2018a, Zhi et al. 2018b, Luo et al. 2019a, Luo et al. 2019b, Zhi et al. 2019, Zhi et al. 2020a, Zhi et al. 2021. All of these studies primarily focused on taxonomical treats, with limited ecological and geographical interpretations or evaluations. However, Cixiidae are obligatory phytophagous taxa and therefore directly linked to the distribution of their host plants (Attié et al. 2008). They are generally considered feeding on a variety of plants (Larivière 1999) but more precisley documented, they appears mostly oligiphagous or monphagous , Bourgoin 2021. The planthopper and its host-plants are both patterned by the historical biogeography of the areas where they are distributed. How Cixiidae do follow the patterns of biogeogaphical distribution (major biological realms, biogeographical regions) already well established in China? Which boundaries can be identified for Cixiidae and at which taxonomical levels? The aim of this paper is to identify these correlations and to investigate how these zoogeographical regions are connected in China.
This current paper provides the first distribution pattern of the Chinese Cixiidae following current Chinese zoogeographical regions recognized and updated species list of Chinese Cixiidae. Accordingly, the objectives of this paper are: (1) to compare Cixiidae species richness at the level of the Chinese zoogeographical regions and to document their distribution patterns and their endemism in each region, both at the tribal and generic level; (2) to investigate what biogeographical patterns the Cixiidae reflect: are they recognized effectively in a particular Sino-Japanese realm or a simple area of transition between the Palearctic and Oriental realms? (3) to provide a comprehensive species list of the Cixiidae from China.

Materials and methods
Eight Chinese zoogeographic regions, based on geographic, climatic, and vegetation characteristics , were used for the bio-geographical analyses: Northeast China, North China, Nei Mongol-Xinjiang, Qinghai-Tibet, South China, Central China, Southwest China and the Taiwan region (Fig. 1). Two other regions were added for countries adjacent to China: 1) a south China 'VM region' including Vietnam, Laos, Thailand, Cambodia, Myanmar, Bhutan, Bangladesh, as well as a small portion of India, and 2) a north East China 'Far East region' including a portion of Russia. The map ( Fig. 1) was created using the National Earth System Science Data Sharing Infrastructure (http://www.geodata.cn). The distribution matrix includes 253 Chinese Cixiidae species (of which 87 species were recorded from museums and the remaining species were recorded from the literature). Among them, 3 species: Cixius narke Kramer, 1981, Oliarus splendidulus Fieber, 1876, andTachycixius (Tachycixius) pilosus (Olivier, 1791), were excluded from the analyses and checklist because we could not confirm their occurrence in China (no specimens information was found in our inspection of museum specimens in the collections) or because of uncertainties about where they were collected. 48 additional Cixiidae species (Suppl. material 1) from adjacent areas based on literature and FLOW (Bourgoin 2021) were added for the cluster analysis. The observed material information of checklist, as a formatted Excel spreadsheet, are provided here in the supplementary materials: Suppl. material 2. Figure 2 and 3 were generated using ArcGIS Version 10.8 statistical software (URL: https://desktop.arcgis.com/en/system-requirements/latest/arcgis-desktop-systemrequirements.htm). The distribution information of the Cixiidae in China was imported into ArcGIS Version 10.8 software, the latitude and longitude of the distribution sites were set as the coordinate attribute elements, and the symbols in the map were set to different colors for distinguishing different genera of the tribes, and finally the maps of the distribution of the tribes and species were exported.
Presence/absence matrices for species and for genera were built for each of the 10 OGUs (physiographical regions as operative geographical units, Crovello 1981). Similarity coefficients use binary data to measure association between OGU. On the basis of a review of similarity coefficients (Shi 1993), the Jaccard's coefficient in NTSYS Version 2.1 software (Rohlf 2000) was used according toLegendre and Legendre (1983) and Rohlf (2000). Clustering of OGUs using the UPGMA algorithm, UPGMA (an unweighted pairwise group method using arithmetic mean) was used to cluster similarities (Legendre and Legendre 1983). Based on the similarity of clustering results, Jaccard's coefficients were analyzed through nonmetric multidimensional scaling (NMDS) according to Kenkel and Orloci (1986).

Data resources
This publication follows the classical systematic classification based on Holzinger et al. (2002) and Emeljanov (2002) as synthetized and updated in Bourgoin (2021) and Luo et al. (2021). Fossil species are indicated by the symbol ( †). The checklist contains information updated up to April, 2021 compiled from scientific papers, book chapters, conference abstracts, theses, and from the FLOW website (Bourgoin 2021). It also includes our own unpublished taxonomic data and original museum specimens information from the following institutions: Shanghai Entomological Museum C.A.S (SEM), Museum of China Agricultural University (CAU), Entomological Museum of Northwest A&F University (NWAFU), Museum of Chinese Academy of Forestry (CAF), Institute of Entomology, Guizhou University (GZU), Chongqing Normal University (CQNU) and Muséum National d'Histoire Naturelle (MNHN). Distribution sets were collected from the original sources with their original latitude and longitude information; Those lacking such information were Distribution: China: Taiwan (Matsumura 1914).

Regional richness and endemism
A species richness gradient occurs from north to south and from west to east for Cixiidae as shown in Fig. 2. Substantial variation in species richness and endemism among the different zoogeographic regions were observed. Table 1 describes the species richness of Cixiidae by region, ranging from 5 species and no endemic species in the Nei Mongol-Xinjiang region, to 161 species and 69.57% of endemic species in Taiwan region. Inbetween, species richness and endemism ratios are distributed in two groups: the Northeast China and the Qinghai-Tibet regions, respectively with 8 and 10 species and 12.5% and 20% of endemism, and the North, Southwest and Central China regions, which have comparable numbers of species and endemism, respectively, with 29, 43 and 60 species and 33-40% of endemism. No significant differences in endemism among regions was observed. More than five-fourths of the species (205 species; 82%) are reported to occur in only in China, depicting a high level of endemism of the Chinese fauna for this family (Table 1).

Distribution patterns of cixiid species in China
Based on the eight zoogeographic regions of China (Fig. 1), 38 main distribution patterns are observed ( Table 2). The number of species distributed in a single region (accounting for regional endemism) is highly variable among the regions: Taiwan (44.80%), Central China (8.00%), Southwest China (6.80%), South China (5.60%), North China (4.00%), Qinghai-Tibet (0.80%) and Northeast China (0.40%). No endemic species were observed in the Nei Mongol-Xinjiang region (Table 2). Nine bi-regional distribution patterns were observed, and among them the South China-Taiwan pattern has the greatest number of species (15 species, 6.00% of the species). Nine tri-regional distribution patterns were also observed, among which, the largest number of species (11 species, 4.40% of the species) was for the Central-South China-Taiwan distribution pattern. The Southwest-South China-Taiwan distribution pattern is depicted by 6 species (2.40% of the species). Five distribution patterns occur in 4 zoogeographic regions, among which the North Southwest-Central-South China region and the Northeast-Central-South China-Taiwan region have two species (0.80% of the total number of cixiids in China). All the remaining four-, five-, sixand seven-regional distribution patterns have only a single species, accounting for 0.40% of the total number of cixiids in China (  Table 2.

Cluster and Ordination
In both the generic and specific taxonomic levels (Fig. 8a, c), the dendograms clearly separate the northernmost regions (Russian Far East, Nei Mongol-Xinjiang and Northeast China regions) from all other regionsand with the similar relationships for Chinese zoogeographical regions: South-Central + SouthWest + North + Taiwan + Qinghai-Tibet. At the species-level the south adjacent China country region appears as sister to all of China.
In contrast, at the generic level, this south adjacent China region sister to the central and south Chinese regions. In the northernmost regions, Russian Far East is closer to the Northeast China region at the species level and closer to the Nei Mongol-Xinjiang region at the generic level. In both analyses, the cophenetic correlation coefficient (r>0.8) is high, indicating close agreement between the cluster assignment and the original Jaccard similarity coefficient matrix.
The cluster analysis and the NMDS ordination generally showed similar interrelationships among regions (Fig. 8b, d). The stress values of 0.18 (generic level) and 0.30 (species level) demonstrate the accuracy of the projections in the matrix in the 2D ordination space. At the generic level (Fig. 8b), the Nei Mongol-Xinjiang and Russian Far East regions are closely related to each other, and the Northeast China, Nei Mongol-Xinjiang, and Russian Far East regions are clearly separated from the other 7 regions. The Southwest, Central, and South China regions are closely grouped together, and are also related to the North China and Taiwan regions, but the Qinghai-Tibet and VM regions are more separated. At the species level (Fig. 8d), a roughly similar pattern occurs and the Russian Far East is closer to the Northeast China region, but the VM region is clearly separated and more distant from all other regions.

Current Chinese Cixiidae diversity and distribution
More than 80% of the Cixiidae species are considered to be endemic to China. The highest endemism is found in Taiwan (69.57%), followed by the Southwest China (39.53%), North China (34.48%) and Central China (33.33%) regions. These figures are consistent with the species richness and endemism patterns observed in other Hemiptera groups, such as aphids (Huang et al. 2008, Gao et al. 2018), leafhoppers (Yuan et al. 2014, or more specifically for planthoppers (Zhao et al. 2020a, Zhao et al. 2020b. For the patterns of distribution, the South China-Taiwan pattern (6.00%), the Central-South China-Taiwan one (4.40%) and the South-Western-South China-Taiwan one (2.40%) are the richer in term of species. This pattern probably results from the past interconnection of the island of Taiwan with the Asian continent during the Quaternary period, when the sea level fell, facilitating the species flow between these areas (Lei et al. 2003, Tang et al. 2006). Its subsequent geographical isolation after the Quaternary period explains its relatively independent pattern of speciation (Gao et al. 2018) and its high endemicity of species.
At the tribal level Cixiini, Pentastirini, and Semonini are widely distributed in China, except i the Northeastern China region for the Cixiini, which is probably a collect artefact as Cixiini are known to occur in higher latitudes (Bourgoin 2021 More recently, the uplift of the Qinghai-Tibetan Plateau starting in the middle of the Eocene period (45-38 Ma), also had profound effects on the topography and watersheds of East Asia, the aridity of inland Asia, and the Asian monsoon system. These abiotic factors produced a three-stage pattern of species distribution, from high in the west to low in the east (Zhang et al. 2000). The vertical differentiation in plant distribution (Jin et al. 2003), affected their diversity and inceased the richness of local speciation events , Favre et al. 2015, and subsequently influenced the species distribution and speciation of the Cixiidae. During the late Oligocene to early Miocene periods (25-15Ma), the expansion of the Tibetan Plateau continued, and the East Asian monsoon and Indian monsoon prevailed in the Asian continent. This resulted in an increase of both temperature and sea levels , which allowed the northward propagation of fauna and flora. This area was pushed back southwards at the end of the Miocene period (10 Ma) by the uplift of the Hengduan Mountains , which caused the climate to cool (Xie et al. 2019, Yu et al. 2020. Since the middle of the Holocene period (6Ka), rainfall declined and monsoon strength weakened, resulting in a dramatic decrease in precipitation in northern China, which affected the vegetative environment (Zhao et al. 2009, Huang et al. 2012. Quantitative precipitation reconstructions based on pollen collected from northern China indicated that a strong sealand pressure and temperature gradient caused by strong summer insolation in the northern hemisphere during the early Holocene period (0.14-0.07 Ma) caused enhanced monsoons (Zhao et al. 2009, Cook et al. 2011, Chen et al. 2015. Obviously the cixiid fauna diversity fluctuated at the same periods along with the diversity of their host-plants. However, without more robust phylogeny studies of Cixiidae, it remains difficult to better infer a more precise biogeographic historical scenario for the family and to link their distribution patterns to any of these important past events.

Biogeographical patterns of Chinese cixiids
Traditionally, the global biogeographical regionalization of China covers both the Oriental and Palearctic realms, which are bounded by the Qingling Mountain-Huai River, around 32-34N in the east of China (Sclater 1858, Wallace 1876, Zhen 1960, Zhang 1999, Cox 2001, Kreft and Jetz 2010, Morrone 2015, Song et al. 2016. In 2013, based on its zoological fauna, Holt added a Sino-Japanese realm standing between the Palearctic and Oriental realms, and from west of Tibet to east of the Japanese archipelago. He located the Palaearctic/Sino-Japanese boundary at about 40-41N, and the Sino-Japanese/Oriental boundary at 24-25N in southeast China (Fig. 1). Kreft and Jetz (2013) questioned the validity of this realm because they regarded it as just a biogeographical transition zone between the Palearctic and Oriental realms. According to their taxa ethoecological characteristics, the Sino-Japanese realm boundaries are generally clustered with the Oriental realm (Kreft and Jetz 2010, Song et al. 2016, He et al. 2018).
This result is also observed here for the Chinese Cixiidae divided into two major zoogeographic areas: the Nei Mongol-Xinjiang and Northeast China regions from the rest of China. This boundary corresponds to the Palearctic/Sino-Japanese north boundary and appears to be more well defined than the Palearctic/Oriental boundary. The Andini tribe serves as a landmark for the Palearctic/Sino-Japanese north boundary, while the Eucarpini and Borysthenini tribes are primarily concentrated south to the Qingling Mountain-Huai River point to the traditional Palaearctic/Oriental boundary as proposed by Zhang (2011). Eucarpini and Borysthenini are landmarks for the south Sino-Japonese realm, clustering with the Oriental realm. Bennini, Briixini, Oecleini and Stenophlepsiini, which are all distributed in Taiwan, may either indicate the northern limit of older and wider distributions of these tribes or might have resulted from occasional dispersions from neighbouring south regions.
At the genus level, the south parts of China cluster with the Indochina region in our analyses, but at the species level all of China forms a unique group. This may be related to the late Eocene uplift of the Himalayas and recent uplift of the Himalayan-Hengduan Mountains in the late Miocene, with a peak before the late Pliocene ( (Feng et al. 2013, Ebersbach et al. 2017. Moreover, Quaternary (2.6 Ma) tectonic movements and the influence of the Indian and Pacific monsoons greatly contributed also to the segregation, dispersal and speciation of Cixiidae in southern China and Southeast Asia (Shi et al. 1998, Liang 2003. The South China region is usually included in the Oriental realm in other studies (Zhang 1999, Zhang 2011, but our analysis indicates that for Cixiidae the South China region is closer to the Central, Southwes, and North China region (Sino-Japonese realm). This is consistent with the results of a quantitative analysis of terrestrial mammals in China and adjacent regions by Xiang et al. (2004), where clustering analysis showed the proximity of South China region to Central and Southwest China regions, and they suggested these regions as the South China Division.

Conclusions
This study is the first zoogeographic analysis based on grid cells of Cixiidae in China and adjacent areas, including all the available data for the family. However this dataset has is own limits: 1) the stronger collecting efforts into southern China and taxonomic studies clearly advanced in the Taiwan region because of studies by Tsaur over the past three decades (Tsaur and Lee 1987, Tsaur et al. 1988, Tsaur 1989a, Tsaur 1989b, Tsaur 1990a, Tsaur 1990b, Tsaur et al. 1991a, Tsaur et al. 1991b, Tsaur and Hsu 2003, Tsaur 2009, 2) the limited to very limited knowledge of Cixiidae in countries adjacent to China, despite studies by Distant (1911), Emeljanov (1974), Fennah (1978), Anufriev (1987), Anufriev and Emeljanov (1988), Hoch (2013), Anonymous (2015), 3) it does not take into account hostplants, which are however key factors also affecting the distribution of these obligatory, phytophagous planthoppers, although host-plants and the planthopper species complex are also together affected by other complex topographic and climatic factors embedded in a long dynamic geological process. Accordingly, if the high diversity of Chinese Cixiidaeno less than 8.6% of the current total species richness of the family (Bourgoin, 2021) -is probably related to the high diversity of Chinese biotopes, the figures presented here probably over-estimate the level of endimicity of the fauna in comparison with the adjacent countries.
With the current available data, the observed distribution patterns reveals that an intercalary Sino-Japanese realm is recognizable between the Palaearctic and Oriental realms. At the regional level, the South China region clusters more closely with the Southwest, Central and North China regions. Taiwan is clearly separated from the South China region and mainland China, but is more closely related to the Qinghai-Tibet region and Indochina countries. The Central and South China regions are close to each other, but the Qinghai-Tibet region is singularly different. However a much better knowledge of the cixiid fauna in the adjacent countries will be needed in the future for a better evaluation and analysis of the singularity of the Chinese fauna. Additionnaly, a yet to be done phylogenetic analysis of the Cixiidae family will be essential to provide the frame of reference allowing to support any reliable historical biogeography scenario of the evolution, development, and distribution of Cixiidae in China.