A cladistic analysis of the subtribe Homalotina Heer is presented. They are hypothesized to be a monophyletic group consisting of nine genera (Anomognathus Solier, Cephaloxynum Bernhauer, Holisomimus Cameron, Homalota Mannerheim, Neomalota Cameron, Stenomastax Cameron, Thecturota Casey, Homalotina gen. 1 new genus, Homalotina gen. 2 new genus), based on two synapomorphies: complete postoccipital sutures on head and macrosetae present on postero-lateral margin of metacoxa. The data set for phylogenetic analysis comprised 83 characters representing 248 character states derived from adult morpholgy. These data were analysed using equal weighting (EW) and implied weighting (IW) (k=1– 6) and supported the monophyly of the subtribe based on two unique characters (complete postoccipital sutures on head and macrosetae present on postero-lateral margin of metacoxa) and two homoplastic characters (head as wide as pronotum and antennal insertion on head slightly anterior to a line drawn between anterior margin of eyes). The topology of the IW trees with k=2–4 was the same and differed with the EW trees. The clade (Homalotina sp. 3 (Homalotina sp. 1, Homalotina sp. 2) was supported in all analyses and the clade ((Neomalota (Homalota flavomaculata (Stenomastax nigrescens, Stenomastax sp. 1))) was supported in all analyses except for the IW (k=2–4). The monophyly of genus Homalota was not supported at all and genus Stenomastax formed a monophyletic group only for the IW (k=2–4) resulting in a new combination [S. flavomaculata (Bernhauer) comb. nov.]. Also, we present two new genera resulting in two clades (Homalota intrusa, Homalota sp. 1) and (Homalotina sp. 1, Homalotina sp. 2)

Microsporidia are obligate fungal intracellular parasites of all animal taxa. Among them the genus Nosema (Nosematidae) is known as the most common entomopathogen. Of these parasites, the ribosomal organization is one of the most pronounced molecular characteristics. One type is the normalarrangement of small subunit (SSU)-internal transcribed spacer (ITS)-large subunit (LSU) in the DNA sequence order. The other is the reverse arrangement of LSU-ITS-SSU. The latter is assigned to be the ‘true’ Nosema in the Nosema/Vairimorpha clade. However, we found that the SSU sequence of a strain of Nosema species having the normal arrangement of its rRNA sequence seemed to be more closely related to the ‘true’ Nosemagroup. Consequently we have further analyzed the complete sequence of rRNA. The results imply that there might be arecombination event in its rRNA evolution and/or the strain may form a novel group near the ‘true’ Nosema group. Interestingly both SSU and LSU of the ‘true’ Nosema and others may be under different selection pressure. We have also found that the size of ITS is distinct between the ‘true’ Nosema and other microsporidian species within the Nosema/Vairimorpha clade. This feature should be a useful diagnostic tool to distinguish the ‘true’ Nosema from others in the clade.