The Japanese Uéno reported 1 species in 1928, and the Taiwan Province Mayfly reported 193 1 2 species in1,among which the Japanese Mayfly is unknown in the above list. Eaton, Epeocus psi Eaton, Ecdyonurus hyalinus Ulmer, Rhithrogena vitrea Ulmer, Isonychia formosana Ulmer, Pseudochloe on Kraepelini Klapá lek * * *. He (194 1) also reported five species of mayflies in Northeast China, including Ephoron Virgo (Olivier1791) and Oligoneuriella Rhenana (Imhoff1850). In addition, Matsumura, Japan (1933) reported 1 species, and Imanishi, Japan (1940) also reported some ephemera in Northeast China, but most of them were unnamed. After sorting and naming by later generations, it is known that there are 10 species that have never been counted before (Bae,1997; British Aerospace Corporation; Liu, 1999). Excluding synonyms, 88 species of Mayflies were known in China before liberation.
During the period of 1942- 1978, the research of ephemera in China came to a standstill. There are only 6 kinds of sporadic reports in the world from Northeast China, Hongkong, Taiwan Province and Yunnan. Gillies et al. (1949, 195 1) were named Cloeon harveyi and Isca purpurea were collected from Hongkong, China. In 1972, Tshernova reported a species of Vietnamella ornata from China and Yunnan, and in 1973, the distribution of Mayflies in China was reported. In 1963, Peters et al. reported a species of Agkistrodon dentata in Hongkong, China, and Tsui and Peters reported its larvae in 1970. Ueno Yoshizo (1969) reported six species of Mayflies in China, Taiwan Province Province and Hongkong, among which Baetiella japonica(Imanishi) was first discovered in China.
Since 1960s, Mr. Xu led the students of Nanjing Normal University to re-study the classification of ephemera, and published a new species in 1978. Up to now, there have been a lot of reports on Mayflies in Chinese mainland, among which Gui Hong (1985) made statistics on the previous work, with a total of 96 species (except synonyms and fossil species, actually 92 species). You Dashou and Gui Hong (1995) finished Economic Insects in China. Braasch & soldá n (1980) reported a species.
In Taiwan Province province, at 198 1, Braasch changed Ulmer's report on the Epeorus psi eation (1885) distributed in Taiwan Province province to Epeorus erratus. In 1985, Müller-Liebenau reported six new species of CERATOPOGONIDAE from Taiwan Province Province. In the same year, waltz &; McCafferty also reported a disease. Kang Shichang (1994-1996) has done a lot of work on the classification of ephemera in Taiwan Province Province, and published 46 new species. Among these newly reported species, except for rotifer, all of them are larvae as model specimens.
To sum up, according to statistics, by the end of 200 1, there were 256 species of mayflies reported in China (table 1 and table 2, the species mentioned in some local chronicles were not counted). The species distributed in China mentioned by Tshernova et al. (1986) were not counted because the specific place of specimen collection was not indicated. The etiology of China Mayflies reported by Braasch( 1999) has been reported by Tshernova et al. (1986) and some local chronicles, and none of the specimens not seen in this study are involved.