Taraxitrichia Flint & Harris, 1992

Pes, Ana Maria Oliveira & Hamada, Neusa, 2003, The occurrence of Taraxitrichia Flint & Harris, 1992 (Trichoptera: Hydroptilidae) in Brazil, with description of the final larval stage, Zootaxa 328, pp. 1-7 : 2-6

Taraxitrichia Flint & Harris, 1992

( Figs 1–16 )

Taraxitrichia Flint & Harris, 1992: 411 Larva (final instar) description: total length 2.0–3.0 mm (n = 7). Head about three times longer than wide ( Figs 3 , 8, 14, 15), bearing several long, thin setae on dorsal region ( Fig. 3 ); frontoclypeal suture incomplete ( Fig. 3 ); antenna with two segments of similar size ( Fig. 3 ). Thoracic notae (with long, thin setae) divided by a longitudinal ecdysial line ( Figs. 1 , 9–11); pronotum longer than wide, meso and metanotum wider than pronotum ( Fig. 1 ); setae on anterior margin of thoracic notae with spinules ( Fig.1 a). Ventrally, prothorax with thin sclerite near posterior margin ( Fig. 2 a); mesothorax with three small sclerites near posterior margin ( Fig. 2 c); metathorax with a pair of sclerites on posterior margin ( Fig. 2 d). Meso and metathorax with pair of hyaline, tubular structures in ventro­lateral region ( Fig. 2 b). Legs long, strong; tarsus with long claw and one spine on its base ( Figs. 4–6 ); prothoracic leg with long, conical, trochantin, bearing a strong apical spine (arrow, Fig. 4 ). Abdominal segment I dorsally with three pairs of small sclerites ( Fig. 1 ); ventrolaterally, with 6–10 small protuberances, not sclerotized ( Fig. 2 e); segment II dorsally with 3 pairs of small sclerites bearing strong setae ( Fig. 1 ), and one lateral protuberance with sclerotized median region ( Fig. 1 b); segments III–VI without sclerites; segment VII, dorsally, with 5 small sclerites ( Fig. 1 ); segment VIII, dorsally, with one plate bearing strong setae with spinules, dorso­laterally with 1 pair of small sclerites, bearing strong setae with spinules ( Fig. 1 ); segment IX, dorsally, with 1 plate bearing long, strong setae with spinules ( Fig. 1 ); segments III–IX, with lateral fringe of short, thin setae. Anal proleg elongated, projecting laterad ( Figs 7 , 12–13); sclerite nearly covers most of the dorsal and lateral region of proleg, bearing three long setae posteriorly, and short, stout setae on margin; anal claw short ( Figs 7 , 12–13). Sclerites of thorax, head, legs and anal proleg light brown; abdomen white in ethanol, shiny green in living larva.

Larval case ( Figs 14–15 ): length 2.5–3 mm (n = 10), constructed of silk and transversally arranged sponge spicules. Larval case cylindrical, with openings at both ends; can be enveloped by the sponge colony. In the pupal stage, both ends are closed and case is attached to the substrate by silk ( Fig. 16 ).

Specimens examined: Brazil, Amazonas, Presidente Figueiredo: igarapé do km 121, Highway BR 174, lat. 01º55'S, long. 60º03'W, 31.i.2003; A.M. O. Pes: 12 larvae (ethanol), 13.ii.2003 A.M. O. Pes; S.R.M. Couceiro; J. O. da Silva: 2 larvae (ethanol), 1 male (genitalia in glycerin, pupal exuviae and other structures mounted on permanent slides), 4 larvae (ethanol), 03.i.2001, A.M. O. Pes; J. O. da Silva: 12 larvae (ethanol), 1 male (genitalia in glycerin, pupal exuviae and other structures on slides), 2 males (genitalia in glycerin, other structures in ethanol); igarapé do Et, Highway BR 174 km 117, lat. 01º58'S, long. 60º03'W, 01.vi.2000: 3 empty cases, 1 larval exuviae (ethanol); 05.vii.2000, 10 empty cases (ethanol), 05.ix.2000 A.M. O. Pes; J. O. da Silva; igarapé do ramal do km 24 da rodovia AM­240 lat. 02º01'S, long. 59º49'W, 05.v.2000:. 10 empty cases (ethanol); 06.ix.2000: 2 pupae (ethanol), A.M. O. Pes; J. O. da Silva and igarapé do ramal do km 28, Highway AM­240, lat. 02º01'S, long. 58º48'W, 03.iv.2000: 1 case and 2 larval exuviae (on permanent slides).

Figures

FIGURES 1 – 7. Taraxitrichia sp. larva. 1, dorsal view of thorax and abdomen (scale = 1 mm): a, setae with spinules; b. lateral projection abdominal of segment II; 2, thorax ventral view (PR, MS and MT), and first abdominal segment (I): a. sclerite of pronotum; b, hyaline tubular structures; c – d, sclerite of meso and metanotum; e, protuberances, not sclerotized of I abdominal segment; 3, head dorsal view; 4, prothoracic leg (arrow indicates the trochantin); 5, mesothoracic leg. 6, metathoracic leg; 7, anal proleg, lateral view (scale = 0.012 mm).

FIGURES 14 – 16. Taraxitrichia sp. larva and pupa. 14, lateral view of larval case and larva; 15, lateral view of larval thorax; 16, view of pupal cases fixed on a sponge colony.