Monographic and Phylogenic Research on Leafhoppers and Treehoppers

Partnership for Monographic and Phylogenetic Research on Leafhoppers and Treehoppers (Insecta: Hemiptera: Membracoidea)

NSF-PEET DEB-9978026, 01/01/2000-12/31/2005
C.H. Dietrich, PI and L.L.Deitz, Co-PI

Leafhoppers and treehoppers (Hemiptera: Cicadomorpha: Membracoidea) comprise a highly diverse, poorly known lineage of insect herbivores. Their species richness–perhaps 250,000 extant species worldwide–rivals that of earth’s entire vascular flora. Over their known evolutionary history, which spans at least 230 million years, these insects have experienced the break-up of Pangaea and the rise and diversification of angiosperms. Membracoids now occupy nearly every terrestrial ecosystem that supports plant life, often in extraordinary abundance, and very few vascular plant families appear to have escaped colonization by these sap-sucking insects. Despite the group’s ubiquity, ecological significance, popularity in ecological and behavioral research, and pest status, taxonomic expertise is scarce and has declined precipitously in recent years, and enormous problems remain in membracoid classification from the species- to the family-group level.

Through ongoing projects, the PIs and collaborators have recently made substantial strides toward reclassifying the family-group taxa based on phylogenetic analyses of morphological and molecular data and creating of a comprehensive biosystematic database for membracoid species. The PEET project addresses additional critical needs in leafhopper and treehopper systematics: (1) training a new generation of systematists with the knowledge and skills necessary to establish effective, independent research programs on the systematics of this hyperdiverse insect taxon; (2) species-level monographic revisions and phylogenies within the largest, most ecologically significant, and most taxonomically problematic membracoid subfamilies; (3) Internet-accessible biosystematic databases on the Membracoidea that synthesize nomenclatural, morphological, ecological, and bibliographic information now scattered throughout museum collections and the vast literature on the group; (4) obtaining new collections of membracoid specimens from undersampled, species-rich regions of the world (Mexico and Southeast Asia). Although these goals extend well beyond the five years covered by this project, PEET funding will enable us to lay the foundation and provide sufficient momentum for an ongoing collaborative effort to produce a stable, comprehensive classification of Membracoidea and to provide much-needed biosystematic information on leafhoppers and treehoppers to the scientific community and public at large. Training components will include morphological and molecular phylogenetic methods, sampling, curatorial techniques, taxonomic monography, efficient storage and retrieval of biosystematic information, and, when appropriate, other specialized methods such as multivariate morphometrics, ultrastructural studies, and molecular identification.

The proposal is strengthened substantially by the partnership involving: (1) the Illinois Natural History Survey (INHS), a  research institute at the University of Illinois and a long history of excellence in the study of biodiversity, maintenance of collections and long-term biological databases; and (2) North Carolina State University (NCSU), long a focal institution for research and training in Membracoidea systematics, with large collections of membracoid specimens and literature. Collaboration between the PI (Dietrich, INHS), Co-PI (Deitz, NCSU), and others at INHS, NCSU, and the U. S. National Museum, Washington, will provide trainees with an unparalleled opportunity to gain knowledge of leafhopper and treehopper ecology, behavior, and sampling methods, and will enable them to acquire the skills in morphological and molecular phylogenetic methods, biosystematic database management, and taxonomic monography necessary to compete effectively for jobs in systematics, contribute to ongoing efforts to document and conserve the world biota, and address basic questions regarding the evolutionary processes that contributed to the diversification of life. By providing phylogenetic context and addressing the ongoing identification crisis in one of the dominant lineages of insect herbivores, this project will likely have direct positive impacts on the fields of insect systematics, evolutionary and conservation biology, ecology, ethology, biogeography, and pest management.