Revisionary Synthesis of the Genus Erythroneura

NSF Systematic Biology Program. DEB-0315373.
C. H. Dietrich, PI.

Highly speciose insect genera with distributions spanning multiple biogeographic realms present a major challenge to revisers as well as those attempting identification. Frequently such genera have been treated piecemeal in regional faunistic works or in small papers describing few or single species, and many have never been revised comprehensively. This has resulted in conflicting interpretations of taxa and character homologies; inconsistencies in the nomenclature, description and illustration of diagnostic characters; and proliferation of synonyms. Existing keys are usually based on a single sex or stage and, for many such genera, a majority of species have never been included in a key. Positive identification thus requires access to a large and obscure literature accessible only to specialists. The sheer size of such genera, many of which comprise hundreds of species, hinders comprehensive study because of various logistical difficulties and the the time required to produce tangible products. Advances in electronic data processing technology have yielded several tools (e.g., digital imaging, relational databases, interactive keys, geographic information systems) that render such projects manageable. The aim of the proposed project is to use such tools to provide a revisionary synthesis of the speciose Holarctic leafhopper genus Erythroneura Fitch. This genus, which presently comprises 600 species, is of interest in part because it is one of the numerically dominant groups of host-specialist herbivores in north-temperate forests and includes numerous pests of horticultural crops.

The goals of this three-year project were:

  1. Compile a digital image archive containing illustrations of the habitus and other diagnostic features for each species and link it to an already completed nomenclatural database;
  2. Enter georeferenced collection records for ca. 40,000 museum specimens of the genus, one record for each unique collecting event/species combination, into the database;
  3. Compile a morphological character state matrix for Erythroneura species and analyze these data using cladistic parsimony methods to test the monophyly of the genus and various species groups recognized by previous authors;
  4. Generate species diagnoses and interactive keys from the character state matrix;
  5. Publish a monographic revision, color atlas, and identification guide for species and provide Web access to the specimen-level taxonomic database and interactive key.