ABSTRACT
The Latin name comes from the Greek word, thysanos, meaning a "fringe" or "tassel," which refers to the long hairs fringing both pairs of wings. The exact relationship of this group of insects to other orders is not certain, but they have features similar to the previous few orders plus those of the Hemiptera and Homoptera and appear to be somewhat advanced over these large groups of plant feeders. Among the several features that link them with the HemipteraHomoptera is the lack of abdominal cerci. The presence of a pupal stage places them close to the Holometabolous orders, along with certain Homoptera that have a pupalike stage. It is doubtful if there is any phylogenetic connection between these orders and the primitive Holometabola, however; it is more likely that the "pupa" stage of these successful groups developed parallel to that of the Holometabola.
