Study On Butterfly Communities And Their Pollen-carrying Features In Crucial Ecological Regions Of The Pearl River Delta

Biodiversity is the cornerstone of human well-being and socially sustainable development.Habitat fragmentation,overused resource,environmental pollution,biological invasions and climate change are the primary causes of biodiversity loss.The Pearl River Delta(PRD),located in Southern China,is one of the most developed areas in China.With increased socioeconomic development,rapid urbanisation has resulted in greenspace fragmentation and deteriorating the health of ecosystems.Therefore,ecological security needs to maintain;ordered and sustainable development faces significant challenges.Butterflies,often used as indicators of habitat quality,are an important group of flowervisiting insects.Researching butterfly community biodiversity and the environmental change in ecological responses in crucial ecological areas of PRD can provide a basis for scientific and effective decision making for the construction of ecological civilisation and sustainable development.In September,November 2019 and July 2020,a baseline survey on the butterfly community was carried out in nine sample plots belonging to three habitat types.The effects of different habitat types on community composition,characteristics of diversity and body sizes were analysed.In addition,the presences of pollen on the butterfly collected in September 2019 was studied,and the effects of different habitat types on the community composition and the features of butterfly carrying pollen were also analysed.The study showed that the butterflies were composed of 133 species belonging to 82 genera and nine families in crucial ecological areas of PRD.In these species,the most abundant family was Lycaenidae(40 species),followed by Nymphalidae species(30species),and those from Amathusiidae(1 specie)were the least.The relative abundance is the highest in Lycaenidae(25.38),followed by Pieridae(24.14),Nymphalidae(14.22)and Satyridae(14.22),and those were low in Hesperiinae and Amathusiidae.Delias pasithoe(Linnaeus,1758),Eurema hecabe(Linnaeus,1758),Mycalesis mineus(Linnaeus,1758)and Neptis hylas(Linnaeus,1758)are the dominant species accounting for 30.72% of the total individuals dominated in this community.Lycaenidae,Nymphalidae,and Hesperiinae had high scores in Margalef richness index and Shannon-Wiener diversity index.Hesperiinae had the highest Pielou evenness index,followed by Papilionidae and Lycaenidae.The Amathusiidae had the highest Simpson dominance index.There was no significant difference in the quantitative characteristics of the butterfly community during different habitat types.However,the tendencies of the numbers of species,genera and individuals were consistent during different habitat types: The numbers of genera,species and individuals were largest in nature reserves(Habitat I),while those were least in urban green spaces(Habitat III).Dominant species' differences were primarily present in types.The Shannon-Weiner diversity index and Margalef richness index of the three habitat types are,from greatest to least,those of nature reserves(Habitat I),country parks(Habitat II)and urban green spaces(Habitat III).The number of individuals of the larger-bodied butterfly was bigger than others in nature reserves.The number of individuals of the smallerbodied butterfly was bigger than others in urban green spaces?The pollen-carrying butterfly comprised 74.19% of all the butterflies at the species level,49.63% at the individual level.The percentages of the pollen-carrying butterfly in Papilionidae and Danaidae were bigger than those in other families at the species and individual levels.The percentage of the pollen-carrying butterfly in Hesperiinae was the smallest at the species level,while that in Satyridae was the smallest at the individual level.Through a comparative analysis in different organs carrying pollen in species and individual levels,the percentages in the ventral sides of wings carrying pollens were biggest both in species and individual levels,while those in the abdomen were smallest.There were large differences in the percentages of the pollen-carrying butterfly both in the organs and the families carrying pollens in species and individual levels.In addition,the differences in the populations of pollen in different organs were large.Legs would carry more pollen more easily than other organs.The percentages of the pollen-carrying butterfly in country parks(Habitat II)and urban green space(Habitat III)were bigger than those in nature reserves(Habitat I)in species and individual levels.There were large differences in the percentages of the pollen-carrying butterfly in the families during habitats types in species and individual levels.There were large differences in dominant species and the percentages of the pollen-carrying butterfly in individual levels during habitats types.The percentages in the ventral sides of wings carrying pollens were bigger than the other organs in different habitats types in species and individual levels,while those in the abdomen were smallest.The percentages of butterflies carrying more than 100 pollens on the ventral sides of wings and legs both in species and individual levels in the nature reserves(Habitat I)were significate bigger than those in the urban green spaces(Habitat II)and the country parks(Habitat II).