Trichoptera Taxonomy And Fauna Of Dabie Mountains

Trichoptera,the adults are also called caddisflies,belongs to the phylum Arthropoda,and is the sixth largest order of class Insecta.Caddisflies are widely distributed in all of the world's Major Biogeographic Regions,and play an important role in water monitoring and evaluation of the health of aquatic ecosystems as bio-indicators.So far,there were over 14,548 described extant species throughout the world,falling into 49 families,and 616 genera.As for 2018,there are 1,418 species in China,belonging to 30 families,and 121 genera.In European and American countries,studies on Trichoptera physiology,ecology,behavior and phylogeny are relatively comprehensive.In China,Trichoptera taxonomy and other researches are still fairly undeveloped.In this dissertation,we chose the Dabie Mountains as the research area and systematically conducted taxonomic and faunistic researches on the Trichoptera in this area.The main work and results are summarized as follows:1.Twenty-seven samplings were taken at 17 sites in the Dabie Mountains with light traps in 2014 and 2015,March to October.A total of 8,279 Trichoptera specimens were collected.Identification indicated that these specimens represented 130 species,belonging to 50 genera,and 23 families.Among these,there were only 108 previously described species.According to the current literature,there are a total of 138 species,51 genera and 23 families recorded in the Dabie Mountains.These species account for 76.67% of the families,41.23% of the genera and 9.73% of the species in China,representing rather high diversity.In this study,22 new species or suspected new species were described,including Psychomyia complexa n.sp.,Psychomyia ensiformis n.sp.,Psychomyia machengensis n.sp.,Tinodes stamens n.sp.(published),Molannodes arcuatus n.sp.,Psilotreta furcata n.sp.,Psilotreta tetrafurcata n.sp.,Apatania protracta n.sp.(published),Apatidelia paramartynovi n.sp.(published),Moropsyche dawuensis n.sp.(published),Uenoa megalobata n.sp.,Rhyacophila brevitergata n.sp.(published),Rhyacophila haplostephanodes n.sp.(published),Rhyacophila longiramata n.sp.(published)and several uncertain species.Among the sampled species,118 species were collected in Hubei Province,49 species were collected in Henan and 69 species were collected in Anhui.Among the collected species,72,22 and 26 species were new records to Hubei,Henan and Anhui,respectively.Four species were new records to China as a whole.All the types of new species are preserved in the Entomological Herbarium of Nanjing Agricultural University,Nanjing,Jiangsu Province,P.R.China.Other specimens collected are preserved in Huazhong University of Science and Technology,Wuhan,Hubei Province,P.R.China.2.All the collected species were described in details,and males' genitalia were illustrated.The phylogeny of each new species and the suspected new species were also discussed.New species groups were further established for some highly specialized new species,for example Rhyacophila haplostephanodes and R.longiramata.3.The spatial and temporal distribution analysis were carried out based on the identification results and the literature review.The results indicated that the collected Trichoptera species in the Dabie Mountains varied significantly by season,and were very different at family level.In June,July and August,we were able to collect more species and numbers of specimens for most families,while in March,April,May,September or October,the Apataniidae,Lepidostomatidae,Glossosomatidae,Hydrobiosidae and Rhyacophilidae species were more prominent.Cluster analysis of 17 sampling sites in different regions showed that the species in the southeast and northwest of the Dabie Mountains each formed a branch separately,while a sample site in the center of the study area formed another branch independently,which may be related to the climate and drainage,and also affected by the biased sampling frequency.The altitude distribution data of Trichoptera in the Dabie Mountains was collected,and a regression analysis was performed.The results indicated that most Trichoptera species in the Dabie Mountains appeard in areas 500-1000 meters above sea level.It is possible that human activity in the lower altitudes is more frequent,and in higher altitudes there are fewer streams,lower temperature and higher wind speed,which are less suitable for Trichoptera than in middle altitudes.4.The distribution information for Dabie Mountains Trichoptera in other parts of China,and worldwide,was collected,and a faunistic analysis was performed.The results indicated that the most frequent Trichoptera species in the Dabie Mountains were East Asian,accounting for 76.09%;Oriental species were the second most frequent,accounting for 10.87%;Oriental + Palearctic species accounted for 7.25%;Palearctic species accounting for 4.35%;Oriental + Palearctic + Afrotropical species and Oriental + Palearctic + Nearctic are respectively 0.72%.Among the East Asian species,1.90% are Sino-Japanese,59.05% are endemic to China,but not to the Dabie Mountains,and 39.05% are endemic to Dabie Mountains.Meanwhile,76.81% of the 138 species of Trichoptera in the Dabie Mountains are distributed in Central China,while they are less distributed in other Chinese geographical regions.It is possible that the differences are mainly caused by the temperature and humidity.The analysis on the distribution of species most similar to those endemic to the Dabie Mountains also showed that the Trichoptera in this area are more closely related to the Oriental region than to the Palearctic region.By combining the faunistic results with paleogeography,paleoclimatology,geology and other data,the origin and evolution of Trichoptera in the Dabie Mountains were discussed.It could be concluded that the insects in the Dabie Mountains originated in eastern China.The current fauna is formed by the climate changes during glacial periods,and the southeast monsoon in China.Our study took samples of Trichoptera throughout the Dabie Mountains for the first time,and obtained rather comprehensive data on Trichoptera in this area.We analyzed the distribution of Trichoptera in the Dabie Mountains for the first time,and found the collected species is significantly varied with time and sites.We also analyzed the Trichoptera fauna of the Dabie Mountains,and preliminary confirmed that it originated in eastern China.