Monday, December 10, 2007 - 9:05 AM

Resolving internal relationships within the Dictyoptera poses new questions: Difficulty in the placement of Polyphaga

Jessica L. Ware, jware42@rci.rutgers.edu1, Jesse R. Litman, jrl72@cornell.edu2, Klaus-Dieter Klass3, and Lauren A. Spearman, spearman@eden.rutgers.edu1. (1) Rutgers University, Entomology, 93 Lipman Drive, New Brunswick, NJ, (2) Cornell University, Entomology, 3124 Comstock Hall, Ithaca, NY, (3) State Natural History Collections Dresden, Museum of Zoology, Königsbrücker Landstrasse 159, Dresden, Germany

Dictyoptera, comprising Blattaria, Isoptera, and Mantodea, are diverse in appearance and life history, and strongly supported as monophyletic. We downloaded COII, 16S, 18S, and 28S sequences of 44 dictyopteran species from GenBank. Ribosomal RNA sequences were manually aligned with reference to secondary structure. We included morphological data for 12 of these taxa and an additional 15 dictyopteran taxa (for which we had only morphological data). We had two datasets, one 59 taxon dataset with 5 outgroup taxa including Phasmatodea (2 taxa), Mantophasmatodea (1 taxon), Embioptera (1 taxon), and Grylloblattodea (1 taxon), and a 62 taxon dataset including 8-OGs, with additional taxa from Plecoptera (1 taxon), Dermaptera (1 taxon) and Orthoptera (1 taxon). We analyzed the molecular dataset in conjunction with 175 morphological characters, using both the doublet and MK models in MrBayes, and using a parsimony heuristic search in PAUP. Within the monophyletic Mantodea, the monophyly of most families is not supported. Unique to our study, the Bayesian 5-OG analysis places Polyphagoidea as a monophyletic sister to Dictyoptera. The 8-OG analysis, and/or the addition of orthopteran sequences resulted in a more traditional placement of Polyphagoidea. Isoptera falls within the “Blattaria”. Separate parsimony analyses of independent gene fragments suggest that gene selection is an important factor in tree reconstruction. When we varied ingroup taxa and/or outgroup taxa, internal dictyopteran relationships differed in the position of several taxa of interest including Cryptocercus, Polyphaga, Periplaneta, and Supella. This provides further evidence that the choice of outgroup and ingroup taxa greatly affects tree topologies.

Species 1: Isoptera Mastotermitidae Mastotermes darwiniensis (termites)
Species 2: Blattaria Polyphagidae Polyphaga aegyptiaca (cockroaches)
Species 3: Mantodea Mantoididae Mantoida schraderi (preying mantis, mantid)