Metrosideros

Davies, Kerrie A., Ye, Weimin, Giblin-Davis, Robin M., Taylor, Gary S., Scheffer, Sonja & Thomas, W. Kelley, 2010, The nematode genus Fergusobia (Nematoda: Neotylenchidae): molecular phylogeny, descriptions of clades and associated galls, host plants and Fergusonina fly larvae 2633, Zootaxa 2633 (1), pp. 1-66 : 41-42

Genus Metrosideros

Met. excelsa Banks ex Gaertn.

Fergusobia pohutukawa (voucher specimen no 359); associated with Fn. metrosiderosi Taylor 2007 . Clade 10 in Fig. 78.

Form of gall. Unilocular basal shoot bud galls, described and illustrated in Taylor et al. (2007). Occur in vegetative and inflorescence shoot-buds, usually originating from terminal buds of the previous year’s growth. Cause shortening of internodes, and swelling of base of shoot.

Morphology of nematodes. Parthenogenetic female small to medium size, with swollen cuticle; open Cshape; medium oesophageal glands; relatively long conoid tail. Infective female unknown. Male small; almost straight to arcuate, cuticle not swollen; tail bluntly rounded; spicule angular, anterior part longer than posterior; bursa arises near stylet knobs ( Taylor et al. 2007).

Morphology of dorsal shield. Fn. metrosiderosae (WINC 063746). Shield restricted to a small area with about 20 sparse raised sclerotised spicules towards anterior margin of AS 1, about 50 towards anterior margin of AS 2, and about 20 medially on AS 3 ( Taylor et al. 2007).

Possible relationships. Grouped in Clade 10; see discussion under S. luehmannii .

Three possible evolutionary processes for the occurrence of the Fn. metrosiderosi / F. pohutukawa association in New Zealand were suggested ( Taylor et al. 2007). The first two inferred directional long distance dispersal of Fergusonina / Fergusobia from Australia to New Zealand, with a host-switching event from each of Eucalyptus and Syzygium , respectively. However, Syzygium is genetically closer to Metrosideros than to Eucalyptus ( Wilson et al. 2001, 2005; Sytsma et al. 2004), so switching to the former may be more likely. The third inferred speciation was via conventional Gondwanan vicariance.

Melaleuceae