(Walker, 1856)
Body
Large larvae up to 12 mm long. Living larvae red. No lateral and ventral tubules (Wiederholm, 1983; Moller Pillot, 1984a).
Head
The head capsule is smooth and shining. Anterior margin of frontoclypeal apotome is straight without a subapical pit. Labral sclerites 1 and 2 present.
Antenna
The antenna consists of 5 segments. The blade is shorter or considerably longer than the flagellum. Small Lauterborn organs distally on the second segment.
Mentum
The mentum has 4 brown median tooth the middle pair smaller than the outer pair and 6 pairs of brown lateral teeth Trib mentum. The middle teeth are not set forward and only the 2 inner teeth are vaguely connected to the ventromental plates. The first lateral teeth are smaller than the neighbouring teeth. The ventromental plates are as wide as the mentum.
Labrum
SI is plumose and labral lamellae a single plate with numerous apical teeth. The pecten epipharyngis consists of 3 toothed plates with distal teeth. The premandible has 2 teeth.
Mandible
The mandible with a distinct pale dorsal tooth, apical tooth and 3 inner teeth are brown Trib intex mandible, The pecten mandibularis is small and seta interna with 4 plumose branches.
Differential characteristics
Phaenopsectra and Sergentia have a similar mentum as T. intextus. Phaenopsectra has a mentum with shining black teeth Phaenops mentum and the headcapsule is granulated and therefore dull (T. intextus shining). Only labral sclerite 2 is present. Sergentia has 4 middle teeth set forward Serg mentum, mandible with 4 inner teeth Serg mandible 8 and only labral sclerite 2 present (both in T. intextus).