| Type specimens are irreplaceable to safeguard the stability of the nomencaltural system and present the detailed information of new published species including,collection date,location,number and gender of the specimen.Holdings of type specimens reflects the degree of taxonomic research in a country or region.The data of type specimens can be used to investigate the study trend of species taxonomy in a region,and can provide important reference for evaluation of species taxonomic research.Hemipteran insects,which are widely distributed,highly diverse and mostly herbivorous,are important pests in agriculture and forestry.While as the third largest order of the insects,most of Hymenoptera insects are predatory or parasitic natural enemies,and play important roles in biological control of insects pests.Up to now,there has no study to investigate the trends of species taxonomy by collecting and utilizing the data of type specimens of Hemiptera and Hymenoptera in China.In this thesis,the database of type specimens of Hemiptera and Hymenoptera in China from1949 to 2017 was established,and content analysis,Arcgis analysis,correlation analysis and other methods were implemented to assess the taxonomic efforts and the spatial and temporal distribution of new species of Hemiptera and Hymenoptera in China.The main results and conclusions are provided.1.For species composition of the dataset of type specimens of Hemiptera and Hymenoptera in China:(1)The dataset included a total of 3780 Hemiptera species belonging to 3 suborders,87 families and 1306 genera as well as 3334 Hymenoptera species belonging to 2 suborders,55 families and 864 genera.(2)The families with the largest number of species and genera were Cicadellidae(1,119 species,253 genera)and Braconidae(816 species,156 genera).The genera with the largest number of species were the Cacopsylla(68 species)of the Psyllidae and Tenthredo(131 species)of the Tenthredinidae.2.For the preservation of Hemiptera and Hymenoptera holotype specimens:(1)A total of 3735 Hemipteran and 3317 Hymenoptera holotype specimens species were stored in 67 and 55 institutes respectively.(2)The largest collection of Hemiptera and Hymenoptera holotype specimens was the Institute of Zoology,Chinese Academy of Sciences,which preserves 1004 holotypes of Hemiptera and 835 holotypes of Hymenoptera,including the collections of 225 species of Aphididae and 133 species of Ichneumonidae.3.For the assessment of taxonomic effort based on the type specimes of Hemiptera and Hymenoptera in China:(1)From 1949 to 2017,a total of 420 authors participated in the publication of new Hemiptera species,while from 1949 to 2010,354 authors participated in the publication of new Hymenoptera species.Along the time series this thesis focused,the number of new species published and the authors participating in species description showed an increasing trend,with the largest number of new species published in the 1980s-1990 s,and after 2007,the number of new species decreased rapidly.(2)The average shelf life for the typecimens was about 12 years,with an obvious time lag from collection of specimen to publication of a new species.More than half of the new species of Hemiptera and Hymenoptera in China were based on only a single specimen when they were published.(3)The statistical analysis showed that 80% new species were from 20% families and were published by 20% authors,which followed the 80/20 rule and indicated an unbalance of taxonomic effort.4.For the geographical distribution pattern of Hemiptera and Hymenoptera type specimens in China:(1)The dataset included,a total of 10120 geographical distribution of Hemiptera new species in China from 1949 to 2017,and a total of 12,221 geographical distribution of Hymenoptera new species from 1940 to 2010.Areas with high species richness were located in the mountainous areas,including the Southwest Mountains of China(Hengduan Mountain,the eastern Himalayas,the Yunnan-Guizhou Plateau),the Qinling Mountains,the Wuyi Mountain,and the Wuzhishan Mountain.(2)In different collection periods,the specimen records were few before 1970 and most records were during 1971-1994,and the distribution records have decreased since beginning of the 21 st century.(3)A total of 42148 Hemiptera type specimens and 29428 Hymenoptera type specimens were collected from 33 provinces.There was significant difference in the number of type specimens collected from different areas.Most collection records were in Cicadellidae(10238),Psyllidae(10116)and Braconidae(7007).Basically,the taxonomic trends of Hemiptera and Hymenoptera in China were analyzed from two dimensions of time and space respectively.As time goes by,the taxonomic effort of Hemiptera and Hymenoptera in China has been continuously enhanced,but the trend of species description has slowed down,and many species have yet to be described.The Alpha taxonomy level of insects in China needs to be further improved.From the space dimension,imbalance exist among different areas and taxa,demonstrating the importance of increasing investment in research on taxonomy of Hemiptera and Hymenoptera and understudied geographic regions should be focused on.This study provides not only some implications for taxonomists to carry out further taxonomic research,but also fundamental data for the protection of insect species diversity,the utilization of natural enemies as well as pest management in China. |
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