IMPACT OF URBANIZATION ON A GALL-INHABITING LEPIDOPTERA ASSEMBLAGE - THE IMPORTANCE OF RESERVES IN URBAN AREAS

This paper examines the structure of a Lepidoptera assemblage in an ur ban environment in South Africa. The Lepidoptera inhabit fungus-induce d galls on Acacia karroo. Habitat patches supporting the moth assembla ge were sampled from rural, urban-reserve, suburban and city sites and the habitat quality at each of these sites was quantified. Gall occup ancy, larval density and species richness were lowest at the most dist urbed, city sites. Non-parametric multivariate techniques showed that the moth-assemblage structure did not differ significantly at rural an d urban-reserve sites. Assemblage structure at the suburban sites was variable and appeared to be transitional in structure between the city assemblage and the rural and urban-reserve assemblages. Habitat quali ty variables however were weakly correlated with moth-assemblage struc ture. The contribution of urban reserves to the local sustainability o f this Lepidoptera assemblage emphasizes the importance of maintaining 'green' areas in and around cities.