Showing papers by "Brian M. Wiegmann published in 2001"

Phylogenetic revision of Agapophytinae subf.n. (Diptera: Therevidae) based on molecular and morphological evidence

Abstract: Agapophytinae subf.n. is a highly diverse lineage of Australasian Therevidae, comprising eight described and two new genera: Agapophytus Guerin-Meneville, Acupalpa Krober, Acraspisa Krober, Belonalys Krober, Bonjeania Irwin & Lyneborg, Parapsilocephala Krober, Acatopygia Krober, Laxotela Winterton & Irwin, Pipinnipons gen.n. and Patanothrix gen.n. A genus-level cladistic analysis of the subfamily was undertaken using sixty-eight adult morphological characters and c. 1000 base pairs of the elongation factor-1 alpha (EF-1 alpha) protein coding gene. The morphological data partition produced three most parsimonious cladograms, whereas the molecular data partition gave a single most parsimonious cladogram, which did not match any of the cladograms found in the morphological analysis. The level of congruence between the data partitions was determined using the partition homogeneity test (HTF) and Wilcoxon signed ranks rest. Despite being significantly incongruent in at least one of the incongruence tests, the partitions were combined in a simultaneous analysis. The combined data yielded a single cladogram that was better supported than that of the individual partitions analysed separately. The relative contributions of the data partitions to support for individual nodes on the combined cladogram were investigated using Partitioned Bremer Support. The level of support for many nodes on the combined cladogram was non-additive and often greater than the sum of support for the respective nodes on individual partitions. This synergistic interaction between incongruent data partitions indicates a common phylogenetic signal in both partitions. It also suggests that criteria for partition combination based solely on incongruence may be misleading. The phylogenetic relationships of the genera are discussed using the combined data. A key to genera of Agapophytinae is presented, with genera diagnosed and figured. Two new genera are described: Patanothrix with a new species (Pat. skevingtoni) and Pat. wilsoni (Mann) transferred from Parapsilocephala, and Pipinnipons with a new species (Pip. kroeberi). Pipinnipons fascipennis (Krober) is transferred from Squamopygin Krober and Pip. imitans (Mann) is transferred from Agapophytus. Agapophytus bicolor (Krober) is transferred from Parapsilocephala. Agapophytus varipennis Mann is synonymised with Aga, queenslandi Krober and Aga. flavicornis Mann is synonymised with Aga. pallidicornis (Krober).

A review of the southern African genus Tongamya (Diptera: Asiloidea: Mydidae: Megascelinae), with a molecular assessment of the phylogenetic placement of Tongamya and the Megascelinae

Abstract: This paper both tests the morphologically based cladistic appraisal of the Apioceridae proposed by Yeates & Irwin (1996) using the 28S ribosomal RNA gene and reviews the systematic status and biology of Tongamya and the subfamily Megascelinae to which it belongs. Yeates & Irwin (1996) concluded that the subfamilies Rhaphiomidinae and Megascelinae, both formerly placed within the Apioceridae, were separate basal lineages of the family Mydidae. The 28S rDNA evidence presented here confirms the sister group relationship of Tongamya and Megascelus, their retention in the subfamily Megascelinae, the removal of that subfamily from the Apioceridae and its placement within the family Mydidae. New material and field observations of flies belonging to the genus Tongamya enable us to expand the known range of Tongamya miranda, describe a second species, Tongamya stuckenbergi sp. n., better diagnose Tongamya and its two included species, and expand on the habitat and flight behaviour of this remarkable and rarely encountered genus of flies.