PHYLOGENY AND BIOGEOGRAPHY OF THE PARASITOID WASP FAMILY MEGALYRIDAE (HYMENOPTERA)

A phylogenetic analysis of the eight extant and three extinct fossil genera of Megalyridae was conducted based on twenty external morphological characters. A minimum length cladogram for the eight extant genera is resolved: Rigel + (Megalyridea + {[Megalyra + (Cryptalyra + Carminator)] + [Neodinapsis + (Dinapsis + Ettchellsia)]}). One equally parsimonious alternative, differing only by the possibly more basal position of Megalyra, is outlined; however, the biogeographical interpretation is similar, in either case. The biogeography of megalyrid genera is discussed in terms of these putative relationships; the relationships and distributions of the six most apical clades are explained in terms of the distribution of continental land masses during the upper Cretaceous, 90 mya. South America, South Africa, and Malay Archipelago are evaluated as possible composite areas. Current megalyrid distributions in the Malay Archipelago are reviewed relative to geological and climatological events since the Miocene. Addition of fossil genera resulted in six equally parsimonious cladograms because of missing data. These are summarized as a strict consensus tree: Rigel + (Megalyridea + [Megalyra + {Prodinapsis + Cretodinapsis + (Cryptalyra + Carminator) + (Neodinapsis + [Maimetsha + {Dinapsis + Ettchellsia}])}]). Although less resolved, this tree corresponds closely to the cladogram based on extant general alone; furthermore, the addition of fossils establishes the Cretaceous age of the dinapsine lineage. The family Megalyridae is postulated to have originated on Pangaea, possibly as early as the late Triassic. A revised tribal classification for the megalyrids is proposed.