Athripsodes taounate taounate Dakki & Malicky, 1980

Ruiz-García, Antonio, Lara-Rodríguez, Andrés & Garzón, Andrés, 2024, Description of the full-grown larva and barcode of Athripsodes taounate taounate Dakki & Malicky 1980 (Trichoptera: Leptoceridae), an Iberic-Maghrebian endemic., Zootaxa 5415 (2), pp. 309-320 : 310-312

Description of the final (fifth) instar larva of Athripsodes taounate taounate Dakki & Malicky, 1980

( Figs 1–18 )

Biometry. Body length of final instar larva 10.5–12.0 mm, head width 0.78–0.89 mm (n = 5).

Head. Head capsule elongate and hypognathous; yellowish with pair of dark bands overlying and lateral of frontoclypeal sutures, converging posteriorly and reaching coronal suture; muscle attachment spots dark brown and round, with well-defined outlines. arranged in dark bands and posterolaterally on parietalia ( Fig. 1 ). Head capsule with complete set of primary setae. Frontoclypeus narrow and triangular with constriction at eye level; three pairs of muscle attachment spots on anterior third and five on posterior two-thirds. Subocular ecdysial line ( Fig. 2 , black arrow) on each side running from frontoclypeal suture anterior of eye downward, then below eye to occipital foramen, making pale gap in dark margin of occipital foramen. Antennae uncharacteristically small for family, originating from socket-like ridge at anterior edge of parietalia ( Fig. 2 , red arrow), each bearing apical seta longer than basal sclerite of antenna. Labrum yellowish, subquadrangular with round apicolateral corners; anterior margin broadly concave; four pairs of setae inserted on dorsal surface. Ventral apotome chestnut brown, elongate, subtriangular; tapered to mid-length and nearly parallel-sided in posterior half; posterior apex with arrowheadshaped tip; adjacent parts of ventral parietalia very dark ( Fig. 4 ). Dark brown mandibles twice as long as wide, each with two setae near lateral base, proximal seta shorter than distal seta, and with two cutting edges, one dorsal and one ventral ( Fig. 3 ).

Thorax. Pronotum with pair of yellowish sclerites, each sclerite with dark brown muscle attachment spots in posterior half and prominent spot in middle; posterior margin black; about 27–30 setae restricted to anterior half of surface; anterior margin with row of 50–60 pale setae of unequal length ( Figs 5, 6 ); prosternal horn lacking ( Figs 7 , 13 ). Mesonotum with pair of yellowish sclerites, each with dark brown muscle attachment spots anteriorly and with black and diagonal mesonotal bar posterolaterally; each mesonotal sclerite with 30–35 setae concentrated on anterior half ( Figs 6 , 12 ); mesosternum without any setae ( Figs 7 , 13 ). Metanotum unsclerotized, with pair of anterolateral groups of sa 3 setae each with 17–21 setae and posteromedian quartet of sa 1 setae of almost equal length ( Figs 6 , 12 , red arrows); metasternum with 1 pair of submedian setae ( Fig. 7 , red arrows).

Legs yellowish brown, fore- and mid- and hind legs successively longer with all tarsi curved and slender but never hooked; coxa, femur and tibia of each foreleg robust and broader than those of other legs ( Figs 8 , 9 ); each foretrochantin elongate with single black seta at distal margin ( Fig 5 , red arrow); ventral edge of each foretibia with two–three pale setae in addition to single thick spine at distal end ( Fig. 11 , black arrows). Trochanters of mid- and hind legs each divided into short proximal and longer distal sections ( Fig. 8 , black arrows). Hind femora each divided into short proximal section and longer distal section. Anterior faces of hind trochanters and femora without many short dagger-shaped setae ( Fig. 10 ); numerous setae on coxae, trochanters, and femora of hind legs but long setal fringes for swimming lacking.

Abdomen. Membranous areas nearly white, sclerotized areas brown. First abdominal segment with two lateral and one dorsal protuberance (variably deflated, Figs 13 with black arrow; 16 with red arrow), lateral protuberances each with one pair of long black setae anteriorly ( Fig. 16 , red arrow) and numerous very tiny spines anteriorly on distinctive, very dark bar, its anterior end downward-curving about 90° and with seta at end ( Figs 13 , black arrow, 16, red arrow), its posterior end horizontal. Lateral fringe present on each side of segments III–VII, consisting of very short, pale hairs; lateral fringe on each side of segment II represented by two short black setae and on segment VIII by row of very short lateral tubercles ( Fig. 18 , black arrows; Wiggins 1996). Abdominal tergum VIII with four posterodorsal setae, submesal pair long ( Figs 14 & 18 , red arrows) and sublateral pair very short ( Fig. 18 , red arrow). Abdominal tergite IX well sclerotized and pentagonal, with ten setae on posterior margin, four pairs (1st, 2nd, 4th, 5th pairs) long and one pair (3rd pair) shorter ( Fig. 14 ); one posterolateral seta present on each side of abdominal dorsum IX ( Fig. 14 , black arrows). Each lateral sclerite of last abdominal segment with five long setae and four or five short setae; anal region without rows of spines and tooth-edged plates; anal claws each with accessory hook ( Fig. 15 ).

Tufted gills each with nine–thirteen filaments, except gills on each side of abdominal segment I with one anterior ventrolateral filament and three anterior subventral filaments ( Fig. 13 , red arrows); positions of gill tufts in abdominal segments I–III shown in Table 3 and Figs 12, 13 , 16 .

Case. Larval case 13–14 mm long (n = 5), curved, tapered (width at anterior opening 2.1–2.5 mm and at posterior opening 1.1–1.5 mm), composed of mineral grains of different sizes that give it an irregular texture ( Fig. 17 ). Posterior opening closed by silken membrane with almost circular central foramen.

DNA analyses. The analysis of the mtCOI barcode region of one male of A. taounate taounate from Benamahoma ( Spain) ( GenBank accession number: OR669953) and one previously unknown larva collected in the same locality ( GenBank accession number: OR669954) showed a genetic distance of 0.00% ( Table 1 ). These values fit well within the intraspecific variability of mtCOI usually observed in caddisflies ( Pauls et al. 2009, 2010; Previšić et al. 2009, 2014). Moreover, the uncorrected p-distances based on the mtCOI gene of these two individuals and other previously sequenced European specimens are in line with interspecific distances commonly reported in Leptoceridae ( Kučinić et al. 2020; Ruiz-García et al. 2022).

Figures

FIGURES 1–8. Larva of Athripsodes taounate taounate Dakki & Malicky 1980: (1) head capsule, dorsal; (2) head capsule, right lateral; ecdysial line, black arrow; antennal apical seta, red arrow; (3) left mandible, ventral; (4) head capsule, ventral; (5) prothorax, left lateral; foretrochantin, red arrow; (6) head, thorax, left dorsolateral; metanotal setal areas sa2 and sa3, red arrows; (7) thorax, ventral; metasternal setae, red arrows; (8) left legs, posterior faces: dt: distal section of trochanter; pt: proximal section of trochanter; df: distal section of femora; pf: proximal section of femora. All figure scales: 1 mm, except (3) scale: 0.5 mm.

FIGURES 9–13. Larva of Athripsodes taounate taounate Dakki & Malicky 1980: (9) right legs, anterior faces; proximal (pf) and distal (df) hind femora; (10) left hind trochanter and femur, anterior faces; (11) left foreleg, anterior face; ventral edge of its tibia with 3 pale setae (black arrows) in addition to single spine at distal end; (12) meso- and metathorax and abdominal segments I–IV, right dorsolateral; single seta on each anterodorsal setal area sa1 of metanotum, red arrows; single seta on each anterodorsal setal area sa1 (black arrows) and dorsal protuberance (ovoid dashed line) of abdominal segment I; (13)) thorax and abdominal segments I–IV, ventral; left ventrolateral and subventral gills of abdominal segment I, red arrows; left lateral protuberance, black arrow. All figure scales: 1 mm, except (11) scale: 0.5 mm.

FIGURES 14–18. Larva of Athripsodes taounate taounate Dakki & Malicky 1980: (14) tip of abdomen, right dorsolateral; posterolateral setae on abdominal dorsum IX, black arrows; posterodorsal seta on abdominal segment VIII, red arrow; (15) tip of abdomen, ventral; (16) abdominal segments I–IV, right lateral; right lateral protuberance, red arrow, and setae of setal area sa1, black arrow, of abdominal segment I; right ventrolateral gill of abdominal segment I, yellow arrow; (17) larval cases, lateral; (18) abdominal segment VIII, right lateral; row of lateral tubercles, black arrows; posterodorsal seta on abdominal segment VIII, red arrow. All figures scale: 1 mm, except (18) scale: 0.5 mm.