Study On Cerambycidae (Coleoptera: Polyphaga) Diversity, Abundance And Impacts At Maoershan, Guangxi

This paper consists of four sections:(I) Introduction,(II) Species record,(III) Biodiversity analysis,(IV) Impacts of Cerambycidae insects on forest vegetation at Maoershan Natural Reserve.In the first section,the species known,distribution,biology,harmfulness and study history of Cerambycidae insects are introduced.In the second section,186 species (subspecies) of longicorn beetles from Maoershan Natural Reserve,which belong to 5 subfamilies 100 genera,are recorded. Classification keys to subfamilies,genera and species are presented. Among the species recorded,genus Magninia Clermont,species Magninia tonkinea Clermont and Eutaenia tanoi Breuning are all new to China and 13 species are not named yet.In the third section,various indices are used to measure species richness and biodiversity of Cerambycidae community at Maoershan Natural Reserve.Species richness is measured by species-abundance distribution. Octaves,raised by Preston (1948) for grouping individuals numbers (r),is used to mark the species-abundance relation,log normal distribution model S(R)=S0exp[-a2(R-Ro)2] is used for simulation,and the result is S(R)=49.5exp[-0.1414(R-l)2] which can reflect comparatively well the species-abundance relation of Cerambycidae community at this area and has its own characteristic (R0=l). The formula S*=S0 (rc)1/2/a,raised by May(1975) for estimation of species of the whole community,is used for a prediction,resulting in S*=233 which approximates relatively to 186 species (subspecies) of the recorded.Community's a diversity is measured by Simpson diversity index,Shannon-Wiener diversity index and Pielou evenness index. The results show that habitats range in a diminishing sequence of diversity indices from broadleaf forest,broadleaf bush,grassland bush to bamboo forest;that altitude belts range from 600-to-1200-m belt,under-600-m belt to 1200-to-1800-m belt,and no longicorn beetles was found above 1800 m;months from July,May,June to August,a diversity analysis shows that complicated habitats can hold higher biodiversity.Community's P diversity is measured by Whittaker similarity index. The results show that season has remarkable effect on component of Cerambycidae community,which suggests that longicorn beetles occur much seasonally;habitat type also has large effect on it,which reflects the dependence of longicorn beetles on host plant;but altitude gradient has smaller effect on it,which is a result of the fact that longicorn beetles' larvae live all their life inside the stem of host plant and are seldom influenced by outside surroundings.Community similarity is measured by Sorenson coefficient and cluster analysis is used at the same time.The results show that similarity between habitats is slightly low.Broadleaf forest is most similar to broadleaf bush,and they cluster together with each other when similarity coefficient is 0.4085,then with grassland bush when 0.3304,and with bamboo forest at last when 0.1904.The study above shows that biodiversity variation of Cerambycidae insects is mostly relative to vegetation types,and altitude gradient as well as season can influence their occurrence and distribution through changing the appearance of plant community and microenvironment in habitats such as temperature and humidity etc..In the last section,the situation of damage caused by Cerambycidae insects at Maoershan Natural Reserve is commented briefly,and some tentative advices are put forward for protection and control of Cerambycidae pest.