Phylloicus paprockii Prather 2003

Datto-Liberato, Felipe Henrique, Moreira-Silva, Larissa & Paprocki, Henrique, 2025, Description of the final instar larva of Phylloicus paprockii and morphological notes of Phylloicus angustior (Trichoptera: Calamoceratidae) in the Southeastern region of Brazil, Zootaxa 5653 (2), pp. 196-210 : 197-201

Phylloicus paprockii Prather 2003

( Figs 4–23 )

Material examined. BRAZIL: Minas Gerais: Aldeia da Cachoeira das Pedras, Senzala Stream (20°06'52.1"S, 44°01'23.2"W; 925 m a.s.l.), vii–x.2018, collected by F.H.D. Liberato, H. Paprocki, L. Moreira-Silva & V. H.M. Machado. Eleven specimens of P. paprockii were examined, including eight final-instar larvae and three adults. Eight adults were obtained by rearing larvae in the laboratory, and three P. paprockii adults were collected directly in the field; the adults emerged on 23.vii.2018 (♂), 8.viii.2018 (♂), and 13.viii.2018 (♀). All specimens are deposited in MCN-PUC Minas .

Distribution. Brazil (Bahia, Espírito Santo, Minas Gerais and Rio de Janeiro).

Description

Larva. Body length mean = 15.42 mm (range 11.1–15.7 mm; n = 8). Head and thorax dark brown, abdomen pale yellow.

Head capsule. About 1.5× longer than wide, oval, lateral contours of head capsule convex in basal half, straight sided, slightly in convergent in genal regions in dorsal and ventral views ( Figs 4, 6 ). Head darker than pronotum and with evident yellowish ovoid muscle scars mostly in posterior half ( Figs 4, 5 ). Frontoclypeal apotome trapezoidal, wider anteriorly, weak constriction at setae 5, four small anterior spots arranged in a straight line and three major spots: two anterolateral major spots at tentorial pits, third major spot in center of posterior region ( Fig. 4 ). Labrum with transverse row of 14 setae ( Fig. 4 ). Triangular ventral apodeme without ornamental structures, not reaching occipital foramen ( Figs 6, 7 ). Genae and sometimes ventral apotome ornamented ventrally with pair of patches of tiny microspicules ( Figs 7, 8 ). Head chaetotaxy dorsally as in ( Fig. 4 ).

Thorax. Pronotum sclerotized, light brown, posterior margin dark; anterolateral processes reaching midlength of head laterally with constricting pair of anteroventral sclerotized hooks ( Figs 9, 10 ), each process bearing two long subapical setae. Anterior margin of pronotum lightly sclerotized, bearing two pairs of long setae and two small yellowish setae, six pairs of setae near lateral edges (setae 2, 5, 6, 7, 8, 9; Fig. 11 ). Mesonotum with pair of irregular subdorsomesal sclerites with anterolateral and anteromedial margins more strongly sclerotized and depressed ( Fig. 11 ). On each sclerite Sa1 with one long seta, Sa2 with one long and two short setae (setae 3, 2, 4), Sa3 on prominent anterolateral sclerite with five long and two short setae ( Fig. 11 ). Metanotum membranous with paired setal areas: Sa1 membranous with one long seta, Sa2 membranous with one long seta and two short setae, Sa3 slightly sclerotized and with four short and three long setae ( Fig. 11 ). Legs pale yellowish and banded with white and black stripes; coxae, trochanters, and femora of forelegs slightly more robust than other legs, tibiae of midlegs and hind legs with conspicuous distal spine ( Figs 12–14 ). Foretrochantins tapered anteriorly and sinuous, not reaching anterior part of head, conspicuously ornamented by conical spicules with acute apices ( Figs 12 , 15, 16 ).

Abdomen. Membranous, yellowish, lighter than head and thorax. Gills with two-four filaments ( Figs 17, 19 ). Segment I with membranous dorsal and lateral humps well developed, round; ventral hump bearing pair of sclerites on posterior part of hump. Segments III–VII setose along lateral line, from anterior edge of segment III through posterior part of segment VIII ( Fig. 17 ). Tergites VIII and IX each with two pairs of long, and two pairs of short dark setae in dorsal view ( Fig. 21 ). Anal prolegs ( Figs 22, 23 ) each with terminal claw, strongly sclerotized, with short accessory hook on medial margin, with four long and two short, stout setae dorsally ( Fig. 21 ).

Case. Length 31.82 mm (range 29.19–37.83 mm, n = 8). Dorsoventrally flattened (depressed), slightly wider anteriorly than posteriorly. Dorsal and ventral surfaces each formed by single ovate leaf fragment, together covering longitudinal central chamber, fastened together with silk; dorsal fragment larger than ventral fragment, with anterior margin convex and posterior margin with deep notch; ventral fragment with anterior margin nearly straight, posterior margin tapered and round ( Fig. 20 ).

Differential diagnosis. The larvae of Phylloicus paprockii are distinguishable from its congeners by the combination of the following characters: (i) distribution of muscle scars on the head capsule ( Figs 4, 5 ); (ii) pronotal anterolateral processes longer and featuring a distinct pair of constricted anteroventral, upturned sclerotized hooks ( Figs 9, 10 ) bearing two long subapical setae; (iii) with white and black striped legs ( Figs 12–14 ); (iv) with the first gill pair absent ( Figs 17, 19 ); (v) with the case constructed of two large leaf fragments instead of several small ones ( Fig. 20 ). The larva of P. paprockii has a muscle-scar pattern similar to that in P. amazonas Prather 2003 but can be distinguished from that species and those of the other species by the presence of three ovoid muscle scars on the posteromesal region of the frontoclypeal apotome and two conspicuous muscle scars in the lateral midline of the head behind the eyes in P. paprockii . Phylloicus passulatus Prather 2003 has a similar pattern with three distinguishable posteromesal muscle scars on the frontoclypeus but the lateral medial muscle scars are smaller and not as conspicuous as they are in P. paprockii . Phylloicus cressae Prather 2003 has just one frontoclypeal muscle scar; P. abdominalis ( Ulmer 1905) , P. aeneus ( Hagen 1861) , P. fenestratus Flint 1974 , and P. obliquus Navás 1931 have numerous muscle scars distributed all over the head. The pronotal anterolateral processes of P. paprockii are curved similar to those of the other Neotropical larvae of the genus, differing only from those in P. amazonas , in which anterolateral processes do not curve dorsad apically, but taper gradually to acute apices directed anterad ( De Souza-Holanda et al. 2020). The base of each of the pronotal anterolateral processes is narrow in P. paprockii , P. aeneus , P. angustior , P. amazonas , P. passulatus , but wide in P. cressae , P. fenestratus , P. bromeliarium Müller 1880 , P. abdominalis , and P. obliquus . The larvae of P. paprockii and P. amazonas can be distinguished from the others by a distinctive, striped color pattern on the legs. Despite the similarity, P. paprockii has one dark band around the mid-length of the mid- and hind femora, two dark bands of the mid- and hind tibiae (around the base and at midlength), and one dark basal band on the mid- and hind tarsi; the larva of P. amazonas has only one dark band around mid-length of mid- and hind femur, tibia, and tarsus. Like P. lituratus Banks 1920 , P. paprockii does not have gills on abdominal segment I, which is different from the other known larvae of Phylloicus . The larval case of P. paprockii resembles those of P. amazonas and P. lituratus with dorsal and ventral surfaces formed by just two ovate leaf fragments, covering a longitudinal central chamber, fastened together with silk.

The two-leaf cases of Phylloicus species are similar to those of the widely distributed Calamoceratidae genus Anisocentropus (worldwide except Europe and South America). Since species of Phylloicus occur only as far north as the southwestern USA and the single North American species of Anisocentropus occurs only in the eastern USA ( Rasmussen & Morse 2025), confusion of the two genera in the field is unlikely.

Figures

FIGURES 4–8. Phylloicus paprockii Prather 2003 larva head. 4–6, head capsule: 4, dorsal; 5, left lateral. Figs 6–8, Scanning Electron Microscopy (SEM): 6, ventral; 7, ventral apotome and adjoining genae with spiculate ornamentation, ventral; 8, detail of tiny microspicules on a gena. Chaetotaxy in Fig. 4 follows Wiggins (1996) and Williams & Wiggins (1981).

FIGURES 9–14. Phylloicus paprockii Prather 2003 larval thorax. 9–10, Scanning Electron Microscopy (SEM): 9, thorax, right lateroventral; 10, details of left anterolateral projection with hook on apex, right lateroventral. 11–14, larval thorax and legs: 11, thorax, dorsal; 12, right foreleg, posterior; 13, right midleg, posterior; 14, right hind leg, posterior. Figs 11–12, chaetotaxy follows Wiggins (1996) and Williams & Wiggins (1981), Sa1 = setal area 1; Sa2 = setal area 2; Sa3 = setal area 3.

FIGURES 15–16. Phylloicus paprockii Prather 2003 larval foretrochantin with Scanning Electron Microscopy (SEM), right lateroventral. 15, complete foretrochantin; 16, apex of foretrochantin.

FIGURES 17–20. Phylloicus paprockii Prather 2003 larva and case. 17, habitus, right lateral; 18, head and thorax, dorsal; 19, diagrammatic distribution of abdominal gills; left lateral; 20, case, ventral. I–VIII = abdominal segments I–VIII; DL = dorsolateral gills; L = lateral gills; VL = ventrolateral gills.

FIGURES 21–23. Phylloicus paprockii Prather 2003 abdominal terga VIII and IX and anal claw. 21, abdominal terga VIII and IX, dorsal; 22, 23, Scanning Electron Microscopy (SEM): 22, abdominal segment IX, caudal, with ventral side up; 23, left half of abdominal segment IX with details of left anal claw, caudal.