Small larvae, 3 mm long. Colour in life unknown.
Frontoclypeal apotome with straight anterior margin, separate labrum and labral sclerites 3-5 distinct.
Antenna with 5 segments decreasing in length from 2 to 5. Lauterborn organs large, as long as 3rd antennal segment, one apical 2nd segment, the other slightly retracted from apex, with long style. Ring organ near middle of segment 1, seta present. Blade extending well beyond flagellum, accessory blade very short.
SI with bases fused, plumose; SII plumose, arising from small pedestal, SIII short, slender; SIV normally developed. Seta premandibularis simple, stout. Labral lamellae pectinate (with c 25 teeth). Pecten epipharyngis tripartite, each tooth pectinate with 5-6 teeth distally. Premandible with 3 teeth, with beard.
Mandible with stout dorsal tooth; apical tooth double length of one of 3 -4 inner teeth, all teeth pale brown. Pecten mandibularis absent. Seta subdentalis inserted dorsally, narrow, reaching middle inner tooth. Seta interna inserted on dorsal surface, seemingly multi-branched.
Mentum with all teeth pale brown. Middle mentum with three teeth, middle smaller, recessed; with 5 pairs of lateral teeth, declining in size until outermost which is pointed somewhat laterad relative to the others. Ventromental plates distinctively shaped, subovoid, in contact medially, with smooth anterior margin, striae concentrated in medio-lateral area - absent from median sector Setae submenti apparently simple.
Lateral tubules absent. Segment 11 dorsomedially without appendages or hump. Procercus simple, unpigmented, arising from membrane directly, with few short anal setae.
The mentum of this larva is distinctive with recessed median tooth on a mentum that otherwise resembles Riethia, including with ventromental plates meeting medially. The mandible differs in having a dorsal tooth, but has the seta subdentalis inserted dorsally as in Riethia.
The larva associated with South American Nandeva on molecular evidence (Cranston unpublished) comes from Far Northern Queensland (FNQ), Australia - Mary Creek on Mount Lewis. All other Australian records of the genus are based on the characteristic pupal exuviae from streams in FNQ including from Mary Creek (Cranston, 1999).