Research Training Program

Smithsonian Institution
National Museum of Natural History

PROJECT SUMMARY
1996

Mariana R. Chani Posse
Facultad de Ciencias Naturales e
Instituto Miguel Lillo
Universidad Nacional de Tucuman
Tucuman, Argentina
Terry L. Erwin, Ph.D.
Curator of Coleoptera
Department of Entomology
"This experience definitely opens your mind. So, be prepared to canalize the brainstorm!"

Neotropical canopy arthropods: A revision of the Treehopper
Genus Horiola (Homoptera: Membracidae)

ABSTRACT
Understanding the diversity patterns in any group of living things, in terms of the evolutionary processes that produce them, is the long range goal of most biologists. Entomologists are particularly attracted to this idea because of the fact that between 40 and 80 percent of the known species of animals and plants are insects. Within this amount, nearly 80 percent of the species of insects are in the tropics. Such is the case of the neotropical genus Horiola (EIomoptera: Membracidae). At the moment that this study began, the only described species for the genus were Horiola ferruginea and Horiola picta. Besides these two species, eight new species of Horiola were collected by canopy fogging in an hectare plot in the tropical rainforest of Ecuador. The published work on Horiola is extremely limited, the pronotum color pattern being the only character used to separate the species. According to Wood (1993) pronotum color pattern is often, at species level, one of the most diagnostic features in the family. In the genus Horiola, pronotum color pattern presents an extraordinary variation among members of the same species. This fact make us doubt its utility in the classification. The main purpose of this revision is to provide descriptions and keys for the accurate identification of Horiola. The keys will be designed to facilitate identification. Cladistic analysis will reflect phylogenetic relationships. This analysis will include external morphological character states and will include the testing of the utility of pronotal features in classification at the species level.

This research was supported by a grant from the Smithsonian Women's Committee.

Letter of Gratitude