Atanatolica decouxi , Razuri-Gonzales, Ernesto, Holzenthal, Ralph W & Rios-Touma, Blanca, 2018

Razuri-Gonzales, Ernesto, Holzenthal, Ralph W & Rios-Touma, Blanca, 2018, New Atanatolica species from Ecuador (Trichoptera, Leptoceridae), ZooKeys 793, pp. 97-114: 97

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Atanatolica decouxi

sp. n.

Atanatolica decouxi  sp. n. Figs 1B, 5, 6, 7, 8


Morphology of the male genitalia of A. decouxi  sp. n. is similar to A. cotopaxi  Holzenthal, 1988 and A. muyupampa  Holzenthal, 1988 from Ecuador and Bolivia, respectively. From A. cotopaxi  , it differs by the slightly posteromesally produced segment IX, the longer preanal appendages reaching the apex of tergum X, and the shape and length of the apicolateral processes on tergum X, which are much shorter in A. cotopaxi  . The putative larvae of A. decouxi  sp. n. has spines on the anterior margin of the legs, similar to those found in A. cotopaxi  , as illustrated by Holzenthal (1988), but the adults are light brown, whereas in A. cotopaxi  , they are dark brown. Atanatolica muyupampa  differs from A. decouxi  sp. n. by the shorter and laterally directed apicomesal processes on tergum X, and the deeper mesal cleft on tergum X between the apicomesal processes; in A. decouxi  sp. n. both of these processes are apically rugose. Additionally, the inferior appendage in A. decouxi  sp. n. is straight in ventral view, but curved mesad in A. muyupampa  .


Adult male. Forewing length 11 ± 0.5 mm (n = 3). General color light brown, forewing membrane light brown, covered in brown setae along the costal margin and yellow setae through the remainder of the forewing. Head with yellow and light brown hairs. Antennae with light brown hairs on the scape and pedicel, flagellomeres with dark brown setae and ring of white setae basally. Maxillary palps light brown, with long, brown hairs. Thorax brown with yellow and brown hairs. Fore and midlegs with coxae and trochanter with light brown hairs, remaining segments with dark brown setae and ring of yellow hairs basally. Hind legs with yellow hairs and interspersed brown spines, increasing in thickness towards the tarsal segments. Tibial spur formula 0, 2, 2.


Segment IX annular, short, with anterior margin sinuous, posterior margin slightly produced mesally (Figure 5A). Preanal appendages as long as tergum X, slender, digitate, setose (Figure 5A, B). Tergum X notched apicomesally, basal portion membranous, with two pairs of sclerotized apical processes; apicomesal processes digitate, slightly directed laterad in dorsal view (Figure 5B), apex rugose; apicolateral processes slightly shorter than apicomesal processes, thumb-like, directed laterad in dorsal and caudoventral views (Figure 5B, D), apex rugose. Inferior appendages with basal portion of first segment broad, setose, mesal margin rounded, apical portion digitate, almost straight in ventral view (Figure 5C), covered with stout, spine-like setae on its mesal surface; second article short, triangular, directed ventrad (Figure 5A, C). Phallic apparatus simple, without any processes; phallobase tubular; phallotremal sclerite complex, consisting of pair of elongated sclerites ventrally, hooked sclerite subapically, and U-shaped sclerite apically (subrectangular in lateral view); endothecal membranes trilobed (Figure 5E).


Largest instars, assumed to be the 5th, up to 13.8 mm in length (n = 89).

Head (Figure 6A) ovate, brown; eyes large; antennae very short; coronal suture very short, broad; ventral apotome a single sclerite, elongate rectangular, unpigmented; head with long, prominent primary setae in postgenal region and along anterior edge of frontoclypeal apotome; parietal region and frontoclypeus covered with short, closely appressed, clear setae; labrum quadrate, prominent, with row of many short to long primary setae along anterior third and many very short secondary setae along membranous apical edge; mandibles broadly triangular, without separate teeth, with smooth mesal scraping edge, patch of curved setae in mesal concavity (Figure 6A, B). Thorax (Figure 6A): pronotum slightly longer than wide, brown, except for unpigmented posterior edge; covered with two sclerites, with many long setae dorsally and laterally on anterior half, anterior edge with row of uniformly spaced short, spine-like setae. Mesonotal sclerites almost completely covering mesonotum, brown, with pair of small elongate-oval darkly pigmented anteromesal marks; with many long setae dorsally and laterally on anterior half, mesal setae forming W-shaped row. Metanotal sa1 (setal area 1) and sa2 sclerites completely fused, forming large single median plate with posterolateral corners extended and directed medially, with brown pigmentation mesally and small patches of pigmentation along posterior edge; covered with long setae; sa3 sclerites long, oval, brown, except for narrow unpigmented mesal edge, with long marginal setae. Meso- and metapleural sclerites large, brown; metasternum (Figure 6D) with pair of ventrolateral patches of ca. 20 long setae. Foretrochantin horn-shaped (Figure 7A). Legs elongate, cylindrical, robust, brown, setose; foreleg the shortest, hind leg the longest; short, spine-like setae present on anterior (mesal) surface of tibia and tarsus of foreleg (Figure 7A and inset) and tarsi of midleg and hind leg, hind tibia with incomplete suture at basal third (Figure 7B, C, and insets); tarsal claws short, thick. Abdomen: long and slender, abdominal gills not apparent; segment I with small, elongate-oval dorsal sclerite and dorsolateral setae, one long, one short (Figure 6A); lateral hump sclerite (Figure 6C) of segment I prominent, elongate, ventral portion heavily sclerotized and encompassing membranous, raised area covered with minute setae, dorsal portion very lightly sclerotized and extending almost to dorsum of segment; with anteromesal and ventrolateral rows of ca. 4-5 setae; abdominal fringe sinuous, very narrow, composed of minute spicules; with small lateral tubercles on segment VIII (identical as those illustrated by Henriques-Oliveira and Santos 2012: fig 2H); dorsal sclerite of segment IX semicircular in dorsal view (Figure 6E upper inset), with ca. 12 alternating short and long setae along posterior edge; anal prolegs (Figure 6E) each with narrow ventral plate in addition to small lateral sclerite and ventral sole plate, dorsolaterally with darkly pigmented secondary lateral sclerite; band of uniform small spines adjacent to anal opening; anal claw with robust primary hook and single dorsal accessory hook (Figure 6E lower inset).

Larval case.

Elongate, narrow, gently curved and tapering, up to 20 mm long (Figure 7D); composed of small sand grains; posterior opening restricted to small opening by silken ring (Figure 7D inset); prior to pupation case fixed to substrate by short silken peduncle (Figure 7E), and anterior opening closed by silken cap with single opening (Figure 7F).


Larvae described here are tentatively assigned to A. decouxi  sp. n. Unfortunately, no adult male metamorphotype pupae were collected to confirm the association. Larvae and adults were collected at the same site, but on different dates, and adults of only the single species were collected. In our previous collections of species in the genus and from museum material, it appears that species of Atanotolica  do not co-occur at a site, lending support to this tentative association. The probable larva of A. decouxi  is very similar to those described previously by Holzenthal (1988) and Henriques-Oliveira and Santos (2014). The larva of A. decouxi  sp. n. described here is very similar to A. nordestina  Henriques-Oliveira & Santos, 2014 in overall color and structure, but the morphology of the small spine-like setae on the anterior surfaces of the tibiae and tarsi may be distinctive; at least they are different from several species illustrated by Holzenthal (1988: figs 34-41) and most similar to those of A. cotopaxi  . The lateral hump sclerite is also very similar to that described for A. cotopaxi  by Holzenthal (1988: fig. 50) and A. nordestina  ( Henriques-Oliveira and Santos 2014: fig 2G). The case of A. cotopaxi  is made of transparent silk with a few rock inclusions ( Holzenthal 1988: fig 71), while those of A. decouxi  sp. n. and A. nordestina  are made entirely of rocks.

Holotype male.

ECUADOR: Imbabura: Reserva Los Cedros, Río de la Plata, 0.32495N, 78.7808W, 1587 m, 15.iii.2012, B Ríos-Touma, G Bragado, T Policha ( UMSP) [UMSP000158717].


ECUADOR: Imbabura: Reserva Los Cedros, Río de la Plata, 0.32495N, 78.7808W, 1587 m, 1♂, 1♀, 15.iii.2012, B Ríos-Touma, G Bragado, T Policha ( UMSP), Reserva Los Cedros, tributary to Río Los Cedros, 0.30374N, 78.782W, 1312 m, 1♂, 2♀, 18-19.x.2011, R Holzenthal, B Ríos-Touma, A Encalada ( MECN).

Additional material examined.

ECUADOR: Imbabura: Reserva Los Cedros, Río de la Plata, 0.32495N, 78.7808W, 1587 m, 84 larvae, 18.x.2011, R Holzenthal, B Ríos-Touma, A Encalada ( MECN), 5 larvae ( UMSP).


We dedicate this species to José DeCoux, an exceptional person who has been protecting Bosque Protector Los Cedros for more than three decades.


Imbabura Province (Ecuador) (Figure 8).

Natural history.

Larvae were found in high densities in the Río de la Plata on rocks adjacent to a large pool and in the riffle below the pool, forming groups of individuals (Figure 1B). All larvae were submerged. Larvae were observed feeding by scrapping periphytic algae growing on rocks. We were not able to differentiate separate stages of larvae collected, but the size distribution suggests continuous growth in this tropical region (Figure 9).

New distribution record

Atanatolica manabi  Holzenthal, 1988:83 [Type locality: Ecuador, Manabi, Santo Domingo de los Colorados (79 km W); NMNH; ♂].

ECUADOR: Carchi: Río Hualchancito near Hacienda Primavera, 0.80279N, 78.21816W, 1200 m, 1♂, 1♀, 11.ix.2017, B Ríos-Touma ( UMSP) (Figure 8).

The species was previously recorded from three males and several series of larvae collected from "Santo Domingo de los Colorados" and vicinity by workers from the Smithsonian Institution in the mid-1970s. The specimens from Carchi represent the only additonal records of the species since those collections. The male genitalia are identical to those illustrated for the holotype by Holzenthal (1988: fig. 21). In the Carchi specimens, the wings of the strikingly colored adults are in perfect condition. The forewings are brown with a large patch of golden hairs on the apical half extending as a band along the posterior (anal) margin to near its base (dorsal on specimen when wings folded at rest). The apical edge of the forewing bears a fringe of bright, white hairs. The legs and antennae are banded with white and brown hairs.