The Taxonomic Composition of the Arthropod Fauna Associated With an Australian Rain-Forest Tree

Abstract

The composition of the arthropod fauna foraging within the canopy of Argyrodendron actinophyllum Edlin (Sterculiaceae) in a subtropical rainforest near Brisbane, Australia, was investigated during a 2-year field study. Collecting methods included flight interception traps, restricted canopy fogging, and hand-collecting. Over 50 000 canopy arthropods were collected and about 760 species sorted, from which 660 were identified at least to the generic level by taxonomists. The arthropod fauna of A. actinophyllum is characterised by the abundance of Clubionidae, Theridiidae, Psylloidea, Phlaeothripidae, Chrysomelidae, Corylophidae, Curculionidae and Braconidae, and by the scarcity of Empididae, Symphyta, Ichneumonidae and Formicidae. The major determinants of the composition of the arboreal fauna are discussed, including biogeographical and historical constraints, rainforest mesoclimate and host phenology, host architecture and biochemistry, and intrinsic composition of the foliicolous fauna. The faunistic composition of this subtropical rainforest tree species exhibits several features common to both temperate trees (such as the high numbers of homopterans and spiders and the limited populations of arboreal ants) and tropical rainforest trees (such as the large beetle populations and the high orthopteran biomass).