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The thorax consists of three segments; prothorax (pronotum), mesothorax (mesonotum) and metathorax (metanotum) clothed in scales which bear the locomotary organs comprising three pairs of legs and two pairs of wings. These are coupled together in flight by the jugum in the more primitive forms and frenulum and retinaculum mechanisms in more advanced forms. They vary in morphology and may be distinctive taxonomically. A pair of scaled articulated plates (tegulae) covers the wing bases. These tegulae may be particularly obvious in some genera. Dorsally the pronotum bears a scaled ‘collar’, the patagium, covering the head articulation.



Although the Noctuoidea have tympanal (auditory) organs within the thorax, most of the tympanate superfamilies (like the pyraloids) have them in the abdomen base. The Thyridoidea completely lack abdominal tympanal organs, although tiny sensory organs may occur in swollen veins in the wing bases of some some Siculodinae (Scoble, 1995: 137)