EVIDENCE FOR MONOPHYLY AND RELATIONSHIPS OF CHALCIDOIDEA, MYMARIDAE, AND MYMAROMMATIDAE (HYMENOPTERA: TEREBRANTES)

Abstract

AbstractTwenty-three characters or character systems of adults and larvae of Terebrantes are analyzed for evidence of monophyly and phyletic relationships of Chalcidoidea, Mymaridae, and Mymarommatidae. The taxa are considered to be a monophyletic group based on 3 hypothesized synapomorphies: mesotrochanteral depressor without fu2-tr2 or mesoscutal portion of t2-tr2; axillar phragma as site of origin for all or part of t,-tr2 muscle; and independent basal ring absent from male genitalia. The family Mymaridae is considered to be monophyletic based on at least 3 apomorphies: fore wing with hypochaeta; head with frontal, median, and supraorbital sulci; and toruli distinctly closer to inner margin of eye than to each other. Chalcidoidea, including Mymaridae, is considered to be a monophyletic taxon based on 3 apomorphies: prepectus externally visible, at least dorsally adjacent to lateral edge of mesoscutum; mesothoracic spiracle positioned at exposed lateral edge of mesoscutum; and multiporous plate sensilla of antenna with unique structure, as described in text. Mymarommatidae is considered to be the monophyletic sister group of Chalcidoidea based on several apomorphies, including 4 autapomorphies: head composed of frontal and occipital sclerites, which are connected by pleated membrane along hyperoccipital region; hind wing stalk-like, without membrane and terminated in bifurcation that clasps fore wing; fore wing with reticulate pattern formed by raised lineations of membrane; and axillar portion of t2-tr2 muscle absent. Phyletic relationship of Serphitidae with Mymarommatidae is deemed inconclusive because relevant internal character states of amber fossil serphitids cannot be determined. It is suggested that mymarommatids be accorded family status, but not be assigned to superfamily until phyletic relationships are more accurately determined in Terebrantes. A matrix summarizes character-state distribution of most characters analyzed for Terebrantes, and a cladogram illustrates hypotheses of character-state evolution and proposed relationships.