Polyneoptera is an assemblage of eleven insect orders comprising the "orthopteroid" insects. It includes familiar insects such as grasshoppers, roaches, termites, earwigs and preying mantises; as well as the more obscure web-spinners, angel insects and ice-crawlers. We present a phylogenetic analysis of the polyneopteran orders based on 18S rDNA, 28S rDNA, Histone 3, and a coded morphology matrix for an extensive sampling of taxa. We investigate the use of congruence between separate datasets as an a priori measure of alignment quality. Our results support the paraphyly of Polyneoptera, the monophyly of Dictyoptera, sister taxon relationships between Embiidina + Phasmatodea and Dermaptera + Zoraptera, and a relatively basal placement of Plecoptera. The analyses also support a sister taxon relationship between the newly described Mantophasmatodea and Grylloblattodea, a small order of cryophilic insects confined to the northwestern Americas and northeastern Asia. This placement coupled with the morphological disparity of the two groups validates the creation of a new order for Mantophasmatodea. Our results also suggest the Direct Optimization (formerly Optimization Alignment) produces alignments that are more predictable across the parameter landscape than alignment via CLUSTAL X, as measured by congruence among independent data partitions. Dense taxon sampling and phylogenetic analysis of six molecular markers (12S, 16S, 18S, 28S, COII, and H3) and morphological data for the order Plecoptera demonstrates that the subordinal groups Arctoperlaria and Antarctoperlaria are monophyletic. Euholognatha and Systellognatha are also monophyletic, with the exception of the genus Megaleuctra which is the basal lineage for the order and deserves recognition as a distinct family (Megaleuctridae). Notonemouridae is strongly supported as a monophyletic clade. Within the Systellognatha Styloperlidae is the basal lineage, followed by Peltoperlidae then Pteronarcyidae, and Perloidea is a strongly supported monophyletic group with Chloroperlidae as sister taxon to Perlidae + Perlodidae. The family Gripopterygidae is strongly supported as paraphyletic. Many Plecoptera (stoneflies) exhibit a pre-mating communication known as "drumming." Species of the genus Isogenoides have complex drumming behavior in which (i) the male calls the female by tapping his abdomen against the substrate, (ii) the female answers with her own distinctive tapping, and (iii) the male responds with a confirmatory series of taps. These drumming patterns are specific to individual species and may vary within a species to form distinct dialects. Phylogenetic analysis for the genus based on six molecular markers (12S, 16S, 18S, 28S, COII, and H3) supports Yugus as its nearest extant relative and I. hansoni as the basal lineage within the genus. Drumming behavioral characters appear to be largely incongruent with the phylogeny.