Nematodes from galls on Myrtaceae. I. Fergusobia/Fergusonina galls on Corymbia spp., with re-description of F. magna and notes on its phylogenetic relationships

Abstract

Fergusobia magna (Neotylenchidae: Fergusobiinae), collected from axial bud (‘stem’) galls on Corymbia tessellaris growing in coastal regions of Queensland, Australia, is re-described. It is characterised by having a combination of a relatively large, variably shaped parthenogenetic female with a slender conoid tail; a relatively large arcuate infective female with a long slender tail with a pointed tip and a relatively anterior vulva; and relatively large, arcuate, open C or Jshaped males with angular spicules having manubrium and shaft forming 66% of their length, slender tail and peloderan bursa arising at 30–50% body length. Other known forms of Fergusobia/Fergusonina galls from Corymbia are outlined, and the morphology of nematodes from them and the shield morphology of their associated mutualistic fly species from Corymbia spp. are described where known. The possible phylogenetic relationships of these associations from Corymbia are discussed.