AbstractsBiology & Animal Science

Systematics of the family Polycentropodidae (Inseecta:Trichoptera: Psychomyioidea) and taxonomic revisions of New World Polyplectropus Ulmer.

by Maria Lourdes Chamorro

Institution: University of Minnesota
Year: 2009
Keywords: Bayesian; Missing Data; Morphology; New Species; Phylogeny; Taxonomy; Entomology
Record ID: 1854399
Full text PDF: http://purl.umn.edu/47877


The monophyly and phylogenetic relationships of subfamilies and genera traditionally classified in Polycentropodidae Ulmer, 1903, one of the most diverse families in the suborder Annulipalpia, with more than 700 species in 3 subfamilies, were tested. Particular emphasis was placed on testing the monophyly of the cosmopolitan genus Polyplectropus. Larval information is unknown for 46% of the taxa included in this study. To understand the effects of including characters with large sets of missing data, three alternative datasets [TOTAL (all available data for all taxa)= 49 ingroup taxa, 122 characters (including highly incomplete characters); LPA (larval, pupal, adult) = 20 ingroup taxa, 122 characters; ADULT (only adult characters) = 49 ingroup taxa, 86 adult characters] were analyzed under parsimony and Bayesian methods. The five outgroup taxa, representing all four extant families in the Psychomyioidea and the single family in the Hydropsychoidea, remained constant in all datasets. The TOTAL and ADULT datasets included all 20 currently recognized polycentropodid genera placed in 3 subfamilies, and the LPA and TOTAL datasets included characters interpreted from structures of the larvae, pupae, and adults. Results rejected the monophyly of Polycentropodidae, as currently defined; however, the monophyly of the three largest cosmopolitan genera, Polycentropus, Polyplectropus, and Nyctiophylax, could not be rejected nor confirmed. The monophyly of the following taxa was strongly supported in all analyses: Cernotina, Cyrnellus, Kambaitipsyche, Neureclipsis, Paranyctiophylax, New World Polyplectropus sensu stricto, Placocentropus, Neotropical Nyctiophylax, and in the outgroup, Psychomyia + Xiphocentron; while monophyly was strongly supported in some, but not all analyses for the following taxa: Cyrnus, Antillopsyche, Pseudoneureclipsis, Polycentropus sensu stricto, Pseudoneureclipsinae, New Zealand Polyplectropus, Polycentropodinae, Cyrnodes scotti + Pahamunaya jihmita. The implementation of two different analytical methods revealed some areas of conflict which would not have been detected under a single method of analysis. Contradictory results among the datasets were primarily due to either inclusion or exclusion of key sets of characters (i.e., immature characters); and second, missing data negatively affected phylogenetic reconstruction when proportions of characters with missing data were high and characters without missing data were unable to provide adequate phylogenetic signal due to high variation in rates of evolution among characters. Therefore, a combination of few overall characters that have high variation in rates of change, plus an abundance of missing data may be problematic and may lead to poorly resolved trees, thus decreased accuracy. This study also emphasized the importance in phylogenetic reconstruction of including data from all available sources. Several taxonomic changes were necessary in order for classification to properly reflect phylogeny. Three new genera,…