Phylogenetic relationships and systematics
Our phylogenetic results (Fig. 4), based on the combined analysis, are highly similar to the morphological analysis (Fig. 2, Fig. 3). Based on the results from our phylogenetic analyses, species in genusDiestramima that are morphologically similar and geographically area similar tend to be grouped together. Due to the lack of samples from Southeast Asian countries, we compared our data with the descriptions of some species of Diestramima by Gorochov et al . (2015) (Fig. 8) and proposed some species that may be closely related. There is currently no description of the male D .yunnanensis . We compared the genital plate of female individuals (Fig. 8. F, by sample No. 2204) collected in Xishuangbanna Tropical Botanical Garden Chinese Academy of Sciences with the description of this site sample by Gorochov et al . (Fig. 8. A46) and found morphological consistency. Therefore, we supplemented the abdominal apex of male D . yunnanensis (Fig. 8. E, by sample No. 2201) based on the results of collection region and phylogenetic tree.D . yunnansis is highly similar to D . propria(F. 8. A31, located in Laos), except that the male has a shorter abdomen apex and paraproct. Laos borders Xishuangbanna Dai autonomous prefecture of Yunnan province in China. Similarly, Myanmar borders Baoshan city of Yunnan province in China. The abdomen apex of male D .conica (Fig. 8. B) is highly similar to D . minor(F. 8. A36, located in Myanmar), but has completely different shape of paraproct.
In Fig. 2, Fig. 3, Fig. 8, species in Vietnam and the area bordering China can be divided into three groups based on the shape of the male abdominal apex, which basically conclude the morphological characteristics of all species in the genus Diestramima . Most males have similar short and simple abdomen apex, but their paraproct are completely different in shape and length (D .bispinosa , D . cycla , D . hainanensis ,D . hamata , D . palpata , D . sp. 1 andD . subtilis ). The second group of males always has a wide and flat abdomen apex, and some of their paraproct tend to be short and blunt round, some tend to be long and pointed (D . eurya ,D . lamina and D . vietnamensis ). The male abdomen apex of the last group is significantly longer than the first two groups, and most of them are curved downwards (D .major and D . sp. 2). This male species with a more slender abdomen apex (D . acutiapicis , D .austrosinensis , D . brevis , D .intermedia ) is widely distributed in the Oriental realm of inland China.Gorochov et al .(2019) divided three subgenera of the genusDiestramima according to the male paraproct and the female genital plate. Paraproct of the subgenus Baculitettix are stick-like (rather long and thin) but with slightly or moderately higher proximal part. In the subgenus Diestramima andExcisotettix , paraproct rather short and usually high (plate-like), with distal part truncate, angular or having hooks and/or teeth (spinules); or paraproct moderately short, almost S-shaped in profile, with proximal and distal parts more or less equal to each other in height, and with angular or almost spinose apex. The difference is that the female genital plate of the subgenus Excisotettix with rather large posteromedian notch and angular projections around this notch. But in our current phylogenetic tree, we have not found a reasonable explanation for distinguishing these subgenera. In all our samples, we found small differences in the length and curvature of the male abdomen apex even within the same species. But the length of the paraproct, especially the shape always remains the same. Combining with the strong similarities between the male abdomen apex of many species mentioned earlier, perhaps the specialization of paraproct occupies a more dominant position in the morphological taxonomic research of the genus Diestramima .