Leptonema boliviense boliviense Mosely

Rueda Martín, Paola A. & Miranda, Águeda Verónica Isa, 2015, Association of immature stages of some caddisfly species from northwestern Argentina with description of a new species of Helicopsyche (Trichoptera: Helicopsychidae), Zootaxa 3949 (2), pp. 203-216 : 211-214

Leptonema boliviense boliviense Mosely

(Figs. 7–8)

Leptonema boliviense boliviense Mosely 1933: 36 [original description]. Flint et al. 1987: 47 [male redescription, distribution].

This subspecies belongs to the L. stigmosum Group. The male of L. boliviense boliviense is recognizable by characters of the male genitalia: The shapes of the dorsal excision of tergum X, the two lateral lobes, and the two pairs of dorsal setal warts. The basal segment of each inferior appendage is slightly wider in the mesal area. The phallic apparatus bears an apical setose lobe, a pair of dorsolateral processes directed posterad and a pair of ventrolateral processes directed anterad, both with apical setae. Leptonema boliviense boliviense is close to the subspecies L. b. plumosum from which it can be differentiated by structures of the phallic apparatus.

Several Neotropical Leptonema species had been associated with their immature stages: L. albovirens ( Walker 1852) ( Flint 1968) ; L. archboldi Flint 1968 ( Flint 1968) , L. eugnathum ( Müller 1921) ( Ulmer 1957) , L. columbianum Ulmer 1905 ( Flint & Wallace 1980) , L. insulanum Banks 1924 ( Flint 1964) , L. poeyi Banks 1938 ( Botosaneanu 1994) and L. tridens Mosely 1933 ( Nessimian & Dumas 2010) .

The descriptions of larvae of L. poeyi , L. alborivens , L. archboldi , and L. eugnathum are rather incomplete, so that only a few larval characters can be compared. The larva of L. boliviense boliviense is the second largest larva of Leptonema described at the moment, with 29 mm ( L. tridens = 31–40mm). The shape of the head of L. boliviense boliviense is similar that of L. columbianum , in dorsal view; L. columbianum is more setose in the labrum and in the anterior area of the head. In L. insulanum the head is long and more nearly rectangular in dorsal view and in L. tridens , the head, in lateral view is sharply narrowed anteriorly whereas in L. boliviense boliviense it is gradually narrowed from the posterior to the anterior area. The mandibles are asymmetrical, but in L. columbianum , L insulanum , and L. tridens the teeth are more prominent and sharper whereas in L. boliviense boliviense the teeth are blunt and the mandibles are shorter and widener. The shape of the mesonotal plates in dorsal view is different: L. boliviense boliviense shows posterolateral margins broad and extended and the coloration in the posterior area is discontinuous mesally whereas L. columbianum and L. tridens have a dark sclerotized area making a complete curve posteriorly. The metanotum in L. boliviense boliviense has its posterior margin stronger and darker. The prosternal sclerite is broad in L. boliviense boliviense , similar to that of L. tridens and L. columbianun . The thoracic legs of L. boliviense boliviense have fewer and shorter setae than those of L. columbianum . The forefemur of L. boliviense boliviense is broader than in L. columbianum and L. tridens , but the forefemur of L. insulanum is even broader than the others. Abdominal gills in L. boliviense boliviense have a central axis surrounded by regular digitate projections, in L. columbianum and in most species of Leptonema , the shape is the same but in L. tridens the gills are rather irregular. The sclerites of abdominal sternum IX are triangular in L. boliviense boliviense , but in L. columbianum and L. tridens the sclerites have rounded angles. Pupal characters are different, too. The mandibles of L. boliviense boliviense are sharper, longer and with smaller teeth than in L. columbianum ; in L tridens , the pupal mandibles are asymmetrical. The hook plates are distributed on the same segments in L. columbianum and L. boliviense , but the shape of each plate is different. Leptonema tridens has a pair of dorsal hook plates on abdominal segment II that are absent in other species, however the shape of the rest of the dorsal plates are very similar those of L. boliviense boliviense . The terminal segment of the L. boliviense boliviense pupa is less setose than that of L. columbianum .

FIGURE. 7. Leptonema boliviense boliviense Mosely 1933: 7 A–B, adult male: 7A, genitalia, left lateral; 7B, phallic apparatus, left lateral. 7C–L, larva: 7C, habitus of larva; 7D, head, dorsal; 7E, pronotum, dorsal; 7F, mesonotum, dorsal; 7G, metanotum, dorsal; 7H, labrum, dorsal; 7I, mandibles, ventral; 7J, thoracic legs; 7K, prosternal plate; 7L, ventral plates of abdominal segment IX. ix=segment IX; x=tergum X; ai=inferior appendages; pdl=dorsolateral process; pvl=ventrolateral process.

Adult. Mean length of each forewing: 17 mm ( Flint et al. 1987). General coloration yellowish without scales on wings and body.

Male genitalia (Fig. 7). Segment IX annular, dorsally broader and with medial carina (Fig. 7A:ix). Tergum X with mesal excision U–shaped in dorsal view; lateral lobe bilobed with two dorsal setal warts (Fig. 7A: x). Inferior appendages long and slender, with basal segment broader near middle; apical segment 1/3 as long as basal segment, curved to midline. Phallic apparatus tubular with membranous apical lobe directed posterad and bearing setae; dorsolateral process of phallic apparatus short, directed posterad with short apical setae (Fig. 7B: pdl); ventrolateral process of phallic apparatus short, directed posterad and bearing short apical setae (Fig. 7B: pvl).

5th instar larva (Fig. 7–8). Mean total length: 29 mm (27–30, n=15). General color brown. Head dark brown, clear around stemmata (Fig. 7C); head almost square posteriorly in dorsal view, nearly round on anterior margin; anterolateral area of head bearing short modified yellowish setae with truncate apices, parietal sclerites each with dorsal longitudinal line of short, strong, gold setae (Fig. 7D). Ventrolateral regions of head with pair of areas with transverse stridulatory lines. Labrum with brush of long, curved, yellowish setae on anterolateral margin; mesal anterior margin of labrum with short setae (Fig. 7H). Mandibles asymmetrical, right mandible with concave area bearing yellowish setae; left mandible with lateral margin strongly sclerotized and with three mesal teeth (Fig. 7I).

Pronotum dark brown with short and truncate setae on anterior margin; posterior margin of pronotum black, strongly sclerotized; each pronotal plate bearing semicircular groove and two small dark spots (Fig. 7E). Mesonotum and metanotum with curved setae in anterior margins; surfaces recovered with dark setae; muscle scar patterns as in Figs 7 F–G. Prosternum irregular, subtriangular, broader anteriorly with short, broad anteromesal projection; posteriorly rounded, coloration pattern as in Fig. 7K. Chaetotaxy of thoracic legs as in Fig. 7J. Forefemur wider in distal 2/3rds, with pointed dorsal process probably associated with stridulation function. Abdomen with pattern of abdominal gills as in Fig. 8 A, lateral line vague. Segment IX with pair of ventral subtriangular plates bearing posterior setae (Fig. 7L). Anal prolegs each with brush of long setae on posterior margin of each lateral plate.

Pupa ( Fig. 8 ). Mean body length: 14 mm (n=3). General color in alcohol yellowish. Mandibles each 2.5 times as long as basal width, curved, pointed, bearing serrated internal margins ( Fig. 8 B). Abdominal tergites III–VIII bearing anterior dorsal hook plates; abdominal tergite III bearing also posterior pair of hook plates ( Fig. 8 C). Terminal segment elongate with two digitate projections bearing lateral setae ( Fig. 8 D).

Biology. Larvae of L. boliviense boliviense were collected in rivers with much marginal vegetation. These rivers and springs have stony bottoms and abundant allochthonous organic debris from the riparian vegetation. The larva builds a retreat, with sand and bigger stone pieces between stones in small waterfall areas. In the stomachs of some larvae we found coarse particulate organic matter, mainly pieces of leaves. The second most commonly found items were algae and some arthropod sclerites.

Distribution. Argentina, Bolivia, Peru.

Material examined. ARGENTINA: Jujuy: Camino a Tiraxi, Arroyo Hondo Bajo Puente, 2400’25”S, 06522’9 W, 1700 m, Romero & Molineri cols, 2 larvae (IBN); Río Yala, 20.vi.2009, 7 larvae (IBN); Salta: Santa Victoria, Río Los Naranjos, 2225’47’’S, 06444’20"W, 1109 m, 13.xi.2004, P. Rueda Martín col., 5 larvae, 1 pupa, 20 males (IBN); Los Toldos, Río Huaico Grande, 2216’44’’S, 06442’39’’W, 1645 m ,, 26.x.1999, 3 males (IBN); Río Huaico Grande, 2216’44’’S, 06442’39’’W, 1645 m, 11.xi.2004, P. Rueda Martín col., 3 pupae, 2 metamorphotype males (IBN); Tucumán: Afluente Río Raco, Manantial, 3.iii. 2009,1 larva, 1 metamorphotype male (IBN); Arroyo Calimayo, antes de la papelera, 265533”S, 0652319”W, 493 m, 28.vii.2006, Rueda Martín col., 6 larvae (IBN).

Figures

FIGURE 8. Leptonema boliviense boliviense Mosely 1933: 8 A, pattern of larval abdominal gills. 8 B – D, pupa: 8 B, mandibles, ventral; 8 C, abdominal dorsal hook plates, dorsal; 8 D, terminal abdominal segment, dorsal. S = simple; D = double; 3 a – 8 a = one each of paired anterior dorsal hook plates of abdominal segments III – VIII; 3 p = one posterior dorsal hook plate of abdominal segment III.