The Diversity Of Insects From Baiyangdian Wetlands

Baiyangdian wetlands are the largest and most typical wetlands of the North China Plain and play important roles in ecological safety in the Beijing-Tianjin-Hebei region. So far, many scientists have studied various aspects of different biological communities such as birds, fish, and plants. However, insects of this area have not been investigated thoroughly and systematically which impacted the assessment of their biodiversity and the protection and utilization’s processes of resources. Therefore, this thesis began in June 2012 to October 2014, have collected nearly 30,000 insect specimens in Baiyangdian wetlands and obtained the firsthand appraisal for analyzing and revealing insect diversity. The relevant research results are summarized as follows:1. Insects were collected with various sampling methods at different sites in Baiyangdian wetlands from June of 2012 to October of 2014. They were identified to 715 species, 549 genera, 143 families, and 14 orders, and complied to an inventory of Baiyangdian wetlands insects. Compared with other wetlands, insect composition in this area was significantly higher.2. This thesis demonstrated geographical distribution characteristics of insect of Baiyangdian wetlands:(1) In term of the world insect geographical realms, most insects are interregional species of the Sino- Japanese and Oriental realms, some in the Palearctic, Sino-Japanese and Oriental realms, and fewer in other cross-realms or distributed solely in the Sino-Japanese realms. It indicated that Baiyangdian is located in an intersection area between the Palearctic and Sino-Japanese realms, and therefore, insects in this area are adaptive to environments of both the Palearctic and Sino-Japanese realms.(2) In term of the Chinese insect geographical regions, the largest groups of species(83species, 11.67%) belong to north China region, the second(73 species, 10.27%) are wildly distributed in China; the interreiongal species of the North and Northeast China, the north and central China, and the north and regions are 31(4.36%), 37(5.20%), and 22(3.09%), respectively. There are fewer species belonging to other regions. This indicated that insect composition in Baiyangdian wetlands was complex.3. Insect communities showed significant variations among different months. We took moths with light trap from April to September of 2013 as a case study of community variation. Moth community of Baiyangdian was composed of 142 species, belonging to 13 families among which Crambidae is the most dominant family, and the next dominant families are Noctuidae and Pyralididae. Nymphula responsalis and Elophila interruptalis are dominant species in Crambidae; dominant species in Crambidae are Niphonix segregate, Herminia dolosa and Condiea cyclica. Moth diversity showed a significantly temporal changing trend: fewer species appeared in May, more occurred in early June, most broke out in early August, and they decreased in late August. Species abundance relations of moths fitted an equation, y=7.63+73.20e(-0.68x), which is close to a logarithmic model, indicating that environmental factors in Baiyangdian were not as good as those in natural habitats so that dominant species/families were more than others.4. There were 109 species of aquatic insects belonging to 79 genera, 27 families, and 7 orders. The dominant communities were species of Diptera, Coleoptera, and Odonata of which most are relatively tolerant species. Of intolerant species(e.g. Ephemeroptera, Plecoptera, and Trichoptera) that were fewer in Baiyangdian, Ecnomus tenellus and species of Baetidae and Caenidae are reatively tolerant. Therefore, composition of aquatic insects showed that aquatic environment and ecosystems of Baiyangdian wetlands was somewhat impacted.5. Aquatic beetles in Baiyangdian wetlands were composed of 28 species, 25 genera, and 7 families. Species of Hydrophilidae reached a maximum in early July, and those of Dytiscidae did in late July. Occurrences of other aquatic beetles were also in July, but their number was relatively lower.6. Baiyangdian wetlands ecosystems have been increasingly declined with global climate changing and increased anthropogenic activities. We categorized all insect resources of Baiyangdian wetlands into four groups-- pollination insects, natural enemy insects, edible and medicinal insects, and enjoyable insects. Eventually, we provided a few suggestions on conservation and development of insect resources which would be useful to scientifically manage and efficiently protect Baiyangdian wetlands ecosystems.