Submitted to: Zootaxa
Publication Type: Peer reviewed journal
Publication Acceptance Date: 2/18/2010
Publication Date: 10/1/2010
Citation: Davies, K.A., Ye, W., Giblin-Davis, R.M., Taylor, G.S., Scheffer, S.J., Thomas, W.K. 2010. Revision of the Australasian genus Fergusobia (Nematoda: Neotylenchida), with molecular phylogeny, and descriptions of clades and associated Fergusonina fly larvae. Zootaxa. 2633:1-66. Interpretive Summary: The paperbark tree, often referred to as Melaleuca in the U.S., is an invasive species in the Florida Everglades. The South Florida Water Management district alone spent more than $13 million from 1991 to 1998 for its control in water conservation areas. Melaleuca is the focus of several major control efforts including nematode worms that feed on this tree. This paper revises the group of nematode worms, provides an hypothesis of relationships between the species using morphological and molecular data, and provides a key to species. The nematode worms are in a mutualistic association with a group of flies, and although there appears to have been co-evolution between the fly and nematode, there is little evidence of co-evolution between these animals and the host plant, host-switching being common. This research will be of interest to scientists and biological control workers.
Technical Abstract: In a mutualistic association with Fergusonina flies, Fergusobia nematodes form galls on Myrtaceous hosts. The genus Fergusobia (Nematoda: Neotylenchida) is revised, an emended diagnosis of the genus is presented, and its putative phylogeny is discussed. There is molecular and morphological evidence for about 20 clades, which are outlined. Evidence for congruence between fly morphology, inferred from the structure of the dorsal shield of third stage larvae, and the clades of nematodes is presented, suggesting coevolution between them. However, there is little evidence of coevolution between the fly/nematode association and host plants, and host-switching appears to have been common, although host-specificity is stringent among most clades. A key to the species and morphospecies of nematodes collected from Corymbia, Angophora, Metrosideros, Syzygium, narrow-leaved Melaleuca, and Eucalyptus is presented.