Introduction
Cave cricket (Rhaphidophoroidea Walker, 1869) as one of the oldest
species of Orthoptera, are widely distributed all over the world. It
considered to be the basis of the six families and one of the oldest
taxa in the Tettigoniidea clade (Song et al ., 2020). They are
gregarious and typical apterous groups, which includes 10 subfamilies
and 87 genera (including 1 fossil subfamily and 2 fossil genera). They
mainly inhabit in dry leaves, stone crevices, caves and other dark humid
environments, therefore their speciation as well as population structure
have relatively strong dependence on geographical isolation (Juanet al ., 2010).
Dating estimates indicated that Rhaphidophoridae originated in the
Cretaceous period during the Mesozoic era with the ancestral area
located both in the northern and southern hemisphere. The current
distribution of Rhaphidophoridae might be explained by a combination of
both dispersal and vicariance events occurred especially in the
ancestral populations. The radiation of Rhaphidophoridae started within
the Pangaea, where the ancestor of Rhaphidophoridae occurred throughout
an ancestral area including Australia, North America, and the
Mediterranean region. The opening of the Atlantic Ocean promoted the
divergence of North American and Mediterranean lineages while the
differentiation of the southern lineages, spread from Australia, appears
to be related to the fragmentation of Gondwana land (Allegrucci &
Sbordoni, 2019). The Indian subcontinent (including India and southeast
Asian countries north of the Indian river) was originally part of
Gondwana continent, and the initial collision between it and Eurasia
probably began in the late cretaceous, and the main collision period
occurred around 55–50Ma, which coincided with the isolation of the
Aemodogryllinae and Rhaphidophorinae. After the collision of the Indian
subcontinent and the Eurasian continent, insects from the two continents
met again here, which also provided rich raw material for later Oriental
insect species (Jia, 2010).
China straddles Palaearctic and Oriental realm, occupies an important
biogeographical position in the world. Recent years, many papers on
molecular biogeography of insects have been carried out in China. Based
on the phylogenetic relation and distribution of four grasshopper genera
of Catantopidae from the south of China, ten areas of endemism have been
recognized (Xu et al ., 2003). The order of the formation of the
10 distribution areas of these insects was as follows: southern Yunnan
and Loess Plateau, Hainan Island, eastern Mountain and Taiwan Island;
The Yunnan-Guizhou plateau, northern Yunnan and Qinling-Daba mountains
formed at the same time, while the southern China and jiangnan hilly
region formed the last. Wang et al . (2020) determined the
phylotaxonomic relationship and differentiation time of the genusSinocyrtaspis endemic to China. Based on the geographic dynamics
and climatological data of its ancestors, it was concluded that the
centres of origin of Sinocyrtaspis were Hunan and north-east
Guangxi. Their ancestors had two dispersal routes ending in Jiangxi and
Zhejiang, after the cold period of the Miocene, some of the ancestral
species remained in Guizhou while others moved out. And as a response to
climate change, species altered distribution areas by moving along
altitude gradients in mountain regions, whereas the anthropogenic global
warming trend has promoted some species moving to high-latitude areas or
caused population differentiation. However, there is still a lack of
biogeographic research on the widely distributed Oriental species,
especially the Rhaphidophoridae in Oriental realm.
China is the main distribution area of Rhaphidophorinae Walker, 1869 and
Aemodogryllinae Jacobson, 1905. Diestramima Storozhenko, 1990 is
(Rhaphidophoroidea: Aemodogryllinae, Kevan, 1977) widely distributed in
the Oriental realm of China (with 70% of known species) and adjacent
countries. Their range is limited to the Oriental realm (tropical and
subtropical mountainous hilly areas), because they usually choose wide
shrub leaves as mating sites. All species of this genus has long
protuberances on the seventh abdominal tergite, and the shape of the
protuberances is significantly different among different species. The
morphological classification system and the relationship between species
are relatively clear. Therefore, Diestramima is a suitable
candidate group for studying the speciation and diversity patterns of
Oriental realm in China and the corresponding geological changes.