Diversity of nectaring insects and their usage of nectar plants in urban parks of Hong Kong

Abstract

There were scarce studies of nectaring insect and their nectar plant in urban parks of Hong Kong. By better understanding of their relationship, urban biodiversity can be enhanced by planting more suitable nectar plant species in urban park management. This study aims to provide more information on the nectaring insect diversity and their relationship with nectar plants. Transect surveys of nectaring insect were done and 7 urban parks and 2 conservation area in Hong Kong were sampled. In this study, 36 survey visits were conducted in the 9 study sites from February to May 2019. 86 species of nectaring insects in urban parks were recorded during the point transect surveys in this study. 85% of the recorded species were Rhopalocera species. Apis species accounts for the majority of the other recorded nectaring insect species. 26 nectar plant species were recorded in the studied urban park area. 85% of the recorded nectar plant species were exotic. There was moderate to strong positive linear relationship (in Pearson Correlation) between the Shannon Diversity Indices and nectar plant species richness of respective study sites. In this study, Lantana camara, Wedelia trilobata and Bidens alba were the most favored nectar plant species by nectaring insect in urban park. Nearly one third of the recorded nectaring insect individuals used those 3 exotic nectar plant species. Native nectar plant species Bauhinia x blakeana, Oxalis corniculate and Ixora chinensis were used by nearly 15% of the recorded nectaring insect individuals. It is recommended to plant more of those 3 native nectar plants in urban park to enhance urban biodiversity.