Thysanoptera phylogeny - the morphological background

The current morphology-based classification of the insect Order Thysanoptera is not based on sound phylogenetic principles. Disagreement exists concerning the level at which the group should be classified. Two sub-orders are generally recognised, and the available evidence suggests a sister-group relationship between these. However, no clear hypothesis of relationships between the family groups, based on defined apomorphies, has been proposed within either of these major groups, and the commonly quoted tribal and sub-tribal classification is clearly artificial. Given that 50% of the recognised genera are monotypic, this paper attempts to set out hypotheses of relationships for future testing by molecular methods.