Relationships among the cyclostome braconid (Hymenoptera : Braconidae) subfamilies inferred from a mitochondrial tRNA gene rearrangement

The arrangement of mitochondrial tRNA genes for lysine (K) and aspartate (D ) from the junction of the cytochrome oxidase II and ATPase 8 genes was det ermined in a range of hymenopteran taxa. This indicated that the ancestral arrangement for the order is 'KD', as found in the Diptera (represented by Drosophila and Anopheles) and basal Orthoptera, Most Hymenoptera that evolv ed after the appearance of parasitism also have the 'KD' arrangement, inclu ding noncyclostome braconids, However, most cyclostome braconids have eithe r a 'DK' or a 'DHK' arrangement (where 'H' refers to the tRNA gene for Hist idine). In both cases, the aspartate tRNA gene is encoded on the mitochondr ial N-strand, Father than the J-strand as is usually the case. This rearran gement identified a monophyletic group not previously recognized, consistin g of Rogadinae + Braconinae + Gnamptodontinae + Histeromerinae + Rhyssalina e + Betylobraconinae + Opiinae + Alysiinae. Only one cyclostome subfamily ( Doryctinae) retained the 'KD' arrangement, suggesting this to be the most b asal of the cyclostome subfamilies, consistent with ectoparasitism being pl esiomorphic for the cyclostomes. However, the Aphidiinae also retained the 'KD' arrangement, leaving unresolved the issue of whether they should be in cluded within the cyclostomes. (C) 1999 Academic Press.