Houdinia is a monotypic genus of moths in the family Batrachedridae. Its sole species, Houdinia flexilissima, is endemic to raised bogs in northern New Zealand. It is classified as "At Risk, Relict" by the Department of Conservation. The caterpillars are sometimes referred to as Fred the thread. Taxonomy This species was first described by Robert Hoare, John Dugdale and Corinne Watts in 2006 using a specimen collected at Torehape wetland, in Waikato. The holotype specimen is a male collected at the Torehape wetland held in the New Zealand Arthropod Collection. Two other taxa which were discovered earlier but which have remained undescribed are likely closely related to this moth: a species which tunnels in Machaerina teretifolia in New Zealand, and another in Lomandra longifolia in Australia. The species appears to be morphologically the most similar to the also recently described Japanese species Epimarptis hiranoi, along with the two undescribed species from New Zealand and Australia. Hoare et al. classified the species in the family Batrachedridae following Ron Hodges' 1998 interpretation, as opposed to the Epimarptidae, because they considered more recent taxonomic developments as yet too immature, but this species might properly be placed in the Epimarptidae, or at least the subfamily Epimarptinae sensu Hodges, depending on the taxonomy used. Etymology Hoare et al. chose "Houdinia", referencing the renowned escape artist Harry Houdini, as generic epithet for humorous reasons – firstly, because the imago must 'escape' from the narrow chamber in which it pupates, and secondly, because it had 'escaped' the attention of entomologists until Watts first noticed it in 2003. The specific epithet "flexilissima", which is Latin for 'very flexible' (the superlative of flexilis), was chosen in reference to the caterpillars. Common name Prior to its scientific description, Watts and Hoare took to calling the caterpillar of this species Fred the thread, which has been promoted as a common name by some websites. Description The larvae (caterpillars) of this species are extremely narrow, long and orange in colour. It reaches a length of approximately 2 cm but is only 1mm in width. The adult moth is approximately 0.5 cm in length and has a wingspan of 1.2 cm. It is silver-greyish in colour. Distribution The species was first discovered by Watts in 2003 at a small bog called Torehape. As of 2006 it was known from only three peatland localities, and thus endemic to peat bogs in the region of