Introduction -- The importance of insects -- Insect biodiversity : regional examples -- Insect biodiversity in the nearctic region -- Amazonian rainforests and their richness and abundance of terrestrial arthropods on the edge of extinction : abiotic-biotic players in the critical zone -- Insect biodiversity in the afrotropical region -- Biodiversity of australasian insects -- Insect biodiversity in the palearctic region -- Insect biodiversity : taxon examples -- Biodiversity of aquatic insects -- Biodiversity of diptera -- Biodiversity of heteroptera -- Biodiversity of coleoptera -- Biodiversity of hymenoptera -- Diversity and significance of lepidoptera : a phylogenetic perspective -- Insect biodiversity : tools and approaches -- The science of insect taxonomy : prospects and needs -- Insect species, concepts and practice -- Molecular dimensions of insect taxonomy in the genomics era -- Dna barcodes and insect biodiversity -- Insect biodiversity informatics -- Parasitoid biodiversity and insect pest management -- Taxonomy of crop pests : the aphids -- Adventive (non-native) insects and the consequences for science and society of species that become invasive -- Biodiversity of blood-sucking flies : implications for humanity -- Reconciling ethical and scientific issues for insect conservation -- Taxonomy and management of insect biodiversity -- Insect biodiversity, millions and millions.