The subfamily Deltocephalinae is presently the largest circumscribed group of leafhoppers, including at least 6500 described species. Deltocephalines feed on phloem sap from numerous angiosperm plant families, and show varying levels of host specificity. Several tribes specialize on grasses (Poaceae) and are among the dominant arthropod components of grassland ecosystems, while others feed on woody or herbaceous plants and are diverse in tropical forests. Some deltocephaline species are important agricultural pests which transmit plant pathogens, especially to gramineous crops (maize, rice, etc.). The classification of the deltocephaline tribes and status of several other closely related subfamilies have been unstable. Recent phylogenetic analyses indicated that Deltocephalinae is polyphyletic, and that at least four other subfamilies belong to the deltocephaline lineage. The purpose of this study was to provide the first comprehensive estimate of the phylogeny of the group and to elucidate synapomorphic characters for its constituent lineages. 102 morphological characters were analyzed in 63 exemplar taxa from 9 subfamilies. Sixteen maximally parsimonious trees of 676 steps were recovered. The consistency index of 0.216 suggested a high level of homoplasy in the characters examined. Deltocephalinae was found to be polyphyletic. Support for most clades was low, but several lineages which received moderate to high support do not support the current classification and suggest that taxonomic revisions are necessary. In the preferred tree, all grass-feeding tribes formed a common lineage.
Species 1: Homoptera Cicadellidae Graminella nigrifrons (Blackfaced leafhopper)
Species 2: Homoptera Cicadellidae Nephotettix (Green rice leafhopper)
Species 3: Homoptera Cicadellidae Scaphoideus titanus (Vine leafhopper)
Keywords: host specialization
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