Triplectides misionensis Holzenthal 1988

Sganga, Julieta V., Angrisano, Elisa B. & Asaroff, Pablo E., 2013, Preimaginal stages of Triplectides misionensis Holzenthal and Triplectides gracilis (Burmeister) (Trichoptera: Leptoceridae: Triplectidinae), with notes on the cases occupied by these species, Zootaxa 3616 (1) : -

Triplectides misionensis Holzenthal 1988

Figs. 1–12 , 23

Larva. Length up to 10.5 mm. Head coloration (in alcohol) homogeneous dark reddish brown, with yellowish oval areas around stemmata. Muscle scars of same coloration as rest of head, except that at posterior end somewhat paler, distributed characteristically as in Fig. 1 . Labrum dark reddish brown. Ventral apotome triangular, with anterior end wide and laterally rounded in some specimens ( Figs. 2, 3 ). Submentum trapezoidal ( Fig. 2 ).

Thorax with pronotum dark reddish brown; anterior edge crenulate: crenulations rounded, except for anterolateral corners produced and pointed, and the adjacent 2 crenulations slightly pointed ( Figs. 4, 5 ); setal pattern as in Fig. 4 . Mesonotum stramineous; sa 1 each with 1 long seta; sa 2 each with 1 long anteromesal, 1 short anterolateral and 1 short posterior setae, sa 3 each with 8 setae (2 long and 6 short) distributed as in Fig. 4 ; muscle scars as in Fig. 4 . Metanotum covered by 2 pairs of sclerites, sa 1 each with single seta, sa 2 without sclerites each with single seta, sa 3 sclerites same length or slightly longer than sa 1 sclerites, each with 3 setae. Prosternum triangular. Metasternum with setal areas bearing 15 to 21 long setae; pair of mesoposterior rows each of 4 setae with basal, circular sclerite ( Fig. 6 ). Foretrocantins each with dorsal margin excavated, anteroventral corner rounded and anterodorsal corner slightly pointed and upturned ( Fig. 5 ). Legs homogeneous dark reddish brown, setose, with chaetotaxy as shown in Figs. 7–9 .

Abdomen with gills simple, present on segments II–VI, segments II–IV with dorsolateral, lateral and ventrolateral gills, V–VI with only ventrolateral gills. Segments II–VII without setae; segment VIII with 2 pairs of short posteromesal setae ( Fig. 10 ). Segment IX dorsal sclerite with 3 pairs of long setae on its posterior margin, 2 lateral and 1 mesal, and 2 pairs of very short setae between those pairs ( Fig. 11 ).

Larval cases. Larvae found only in empty cases of Grumicha grumicha (97%) and Nectopsyche gemma (3%). For both kinds of cases, larva building cap of little stones covering dorsal portion of anterior opening ( Fig. 23 ). Additionally, for cases of G. grumicha, larva adding threads of silk inside anterior end of case. When larva preparing to pupate, dorsal cap removed and stone added to cover opening.

Larvae of Triplectides sp. in discarded cases of Nectopsyche sp. and Grumicha sp. were previously reported by Holzenthal (1988) and Crisci-Bispo et al. (2004) from Brazil. As opposed to what we observed in this research, Crisci-Bispo et al. (2004) found that 57% to 89% of the larvae of Triplectides sp. were occupying cases of Nectopsyche sp. while only 3 specimens were in cases of Grumicha sp.

Pupa. Length up to 13 mm. Head with 1 pair of setae on vertex and 5 setae on each antennal scape (2 dorsal and 3 anterobasal); labrum with 3 groups of setae along its edge, each group with 3 long setae (3 setae in mesal group and 3 in each lateral group).

Abdomen. All abdominal terga with setae. Segment I with 1 anterior pair of dorsal setae; segments II–VIII with 2 pairs (1 anterior and 1 posterior), except for segment VII with 3 pairs (1 anterior and 2 posterior); segments III–VIII with additional pair of lateral setae. Segment IX with anterolateral protuberances each bearing 5 long setae; ventrolateral lobes each with 5 setae.

Material examined. Argentina: Misiones: arroyo Moreno, 26. x.2004, 2 larvae; picada 13, 25–31. x.2004, 4 larvae; arroyo Moreno, 6–11. xii.2004, 3 larvae; arroyo Tamanduá (virgencita), 6–11. xii.2004, 1 larva; arroyo Tateto, 6–11. xii.2004, 12 larvae; arroyo Moreno, 16–27. ii.2005, 18 larvae; arroyo Tamanduá (virgencita), 16–27. ii.2005, 14 larvae; arroyo Tateto, 16–27. ii.2005, 5 larvae; arroyo Cuñá-Pirú (salto), 8–14. i.2006, 4 larvae; arroyo Tamanduá (virgencita), 8–14. i.2006, 20 larvae; arroyo Moreno, 13–20. xi.2006, 5 larvae; arroyo Tamanduá (virgencita), 8–14. i.2006, 2 male metamorphotypes; arroyo Tamanduá (virgencita), 11. iii.2008, 13 larvae, 2 pupae, 1 male metamorphotype.

Figures

FIGURES 1 – 12. Triplectides misionensis larva. 1, head, dorsal; 2, head, ventral; 3, ventral apotome; 4, thorax, dorsal; 5, pronotum, left lateral; 6, thorax, ventral; 7 – 9, left fore-, mid- and hind legs, posterior; 10, habitus, left lateral; 11, segment IX and anal prolegs, dorsal; 12, segment IX and anal prolegs, left lateral.

FIGURES 23 – 24. 23, Triplectides misionensis, larval case, right lateral; 24, Triplectides gracilis, larva and larval case, right lateral.