A phylogenetic investigation of the planthopper superfamily Fulgoroidea (Insecta: Hemiptera) with emphasis on the family Fulgoridae

The planthopper superfamily Fulgoroidea (Insecta: Hemiptera) is a diverse group of phytophagous insects, with more than 9000 described species worldwide. Although many are of biological interest due to their economic importance as crop pests, or their often unusual morphology, the current understanding of the evolutionary diversification of this insect group is limited.;Chapter one of this dissertation presents phylogenetic reconstructions of families comprising the planthopper superfamily Fulgoroidea based on nucleotide sequence data generated from four genetic loci (18S rDNA, 28S rDNA, Histone 3, and Wingless). These data are used to test competing hypotheses of fulgoroid phylogeny. Results support Asche's (1987) hypothesis of a functional trend in ovipositor structure across planthopper families. This chapter has been published as: J.M. Urban & J.R. Cryan. 2007. Evolution of the planthoppers (Insecta: Hemiptera: Fulgoroidea). Molecular Phylogenetics and Evolution 42: 556-572.;Chapter two of this dissertation presents phylogenetic reconstructions of the family Fulgoridae based on nucleotide sequence data from five genetic loci (18S rDNA, 28S rDNA, Histone 3, Wingless, and Cytochrome oxidase I). Chapter three presents phylogenetic reconstructions of Fulgoridae based on the combination of morphological characters and the molecular data presented in Chapter 2. Results of Chapters 2 and 3 indicate the need for a revised classification of Fulgoridae, and suggest that the higher level classification should reflect fulgorid biogeography.;Chapter 4 presents phylogenetic reconstructions of a bacterial endosymbiont, Sulcia muelleri, of planthoppers in the family Fulgoridae. Nucleotide sequence data encoding a region of 16S rDNA of the endosymbiont was generated. Results suggest that the Sulcia muelleri endosymbionts may have diversified in parallel with their fulgorid hosts.