Marilia siolii Marlier 1964
Creators: name: Camargos, Lucas M.
name: Pes, Ana Maria
name: Hamada, Neusa
Publisher: name: Zenodo
Year: 2020
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Trichoptera
Odontoceridae
Marilia
Marilia siolii

description: Marilia siolii Marlier 1964
(Figs 5, 25–28, 29)
Marilia siolii Marlier 1964, 97–101, plate 37 Figs 1–10 [original description]; Paprocki et al. 2004, 14 [checklist]; Paprocki & França 2014, 67 [checklist]; Holzenthal & Calor 2017,364 [Catalog; as M. sioli].
Diagnosis: This species has male genitalia similar to those of M. albicornis (Burmeister 1839) in the overall shape in lateral view, but the tibial spur formula is 2-4- 4 in the species described by Marlier, instead of 2-4- 2 in M. albicornis; the arrow-like shape of segment X in the first species is different from the acute one in the latter; and the shape of the lateral sutures of segment IX are not completely separating the mid-height suture as it is in M. albicornis. The larvae are similar to those of M. manicorei sp. nov. in the black lines and spot patterns of the head. However, M. siolii has many brown spots on the thoracic sclerites that are not present in the aforementioned species.
Male complementary description: Forewings each 7.76 mm long (n = 1). Body and forewings brown and transparent and covered with gray setae in alcohol.
Head: Eyes very large in males, touching on dorsal region of head (Figs 25a, 25b). Pair of vertexal mediantennal compact setose warts fused as longitudinal ellipse, covered by long, rigid and straight setae, pairs of vertexal lateroantennal warts and occipital warts not visible, pair of posterior warts long and narrow (Figs 25a, 25b). Antennae long, about two times as long as body, with narrow annuli; scapes each about twice as long as broad, with small pale areas basodorsally and apicodorsally, covered with light setae. Front pubescent, covered with light setae, pair of frontogenal warts long and narrow (Figs 25c, 25d). Maxillary palps well developed, each 5-articulated, densely covered with setae. Labial palps each 3-articulated, articles subequal, covered with setae.
Thorax: Prothorax less than half as long as head; pronotum with pair of transversely elongate setal warts. Mesothorax broad, mesonotum without setae and with median longitudinal dark line reaching mesoscutellum; mesoscutellum almost circular and with pair of setal warts and small posterior depressions. Metathorax half as long as mesothorax, without setae. Tibial spur formula 2-4-4; external spurs of median and posterior tibiae shorter than internal spurs. Forewings each with fork I arising near midlength of discoidal cell, R1 and R2 merging before wing margin (Fig 26a). Hind wings each with fork I arising on apical third of discoidal cell, R1 and R2 merging before wing margin; anal lobe with brush-like tuft of long setae (Fig 26b).
Abdomen: Simple, without differentiated structures.
Male genitalia: Segment IX in lateral view with anterior margin sinuous and posterior margin slightly projected at mid-height; midlateral sutures partially separating each side of segment into 3 parts with suture between two upper parts not entire anteriorly, ventral part occupying almost half of height of segment (Fig 27a); dorsal part not projecting above segment X (Fig 27b). Preanal appendages, in lateral view, elongate, finger-like, each with apex blunt (Fig 27a); oblong in dorsal view, with numerous setae and base as wide as apex (Fig 27b). Segment X with apex subtriangular in lateral view (Fig 27b); triangular, broader at base and subapically, apex round in dorsal view, without median incision (Fig 27b). Inferior appendages each with two articles: Basal article cylindrical, with base slightly broader than apex, slightly curved mesad; apical article short, with small conical spines apically; in ventral view with internal margin slightly sinuous (Fig 27c). Phallus tubular, in lateral view curved about 70 caudad near base (Fig 27d); in ventral view straight (Fig 27e); endotheca membranous, with small conical spines; phallotremal sclerite C-like, with inferior paddle-like branch in lateral view (Fig 27d), cup-shaped in ventral view, with basal point on each side and 2 apical horns (Fig 27e).
Final Instar Larva: Body length 5.9 mm (n = 1). Background color of sclerites yellow and abdomen light gray in alcohol (Fig 28a).
Head: In dorsal view subrectangular, broadest one-fourth distance from base; light yellow with distinctive brown U-shaped lines lateral of frontoclypeal sutures on fine carinae and along short coronal suture, frontoclypeus with sinuous submesal lines (Fig 28c); in ventral view with pair of pale brown lines and with dark spots on posterior half, ventral apotome 3.5 times as long as broad and separating genae entirely (Fig 28e). Eyes not clearly rimmed by light areas (Fig 28e). Labrum with convex apicolateral margins slightly broader than convex basolateral margins, slightly concave apical margin as broad as concave basal margin; setae 1 and 2 on each side robust, with row of smaller setae (papilloforms) between them, with setae 3, 4, 5, 6 straight and of less rigid thickness (Fig 28f). Mandibles robust, asymmetrical, with two vestigial sub-basomesal teeth on right mandible and strong mesal tooth near midlength of left mandible (Fig 28g).
Thorax: Pronotum yellow, with setae on anterolateral corners, anterior margin almost straight, black median longitudinal line reaching posterior margin, with pair of regions of other dark spots near posterior margin. Mesonotum divided into 3 pairs of sclerites: On each side, anteromesal sclerite (sa 1) yellow with row of anterior dark spots, one thin dark stripe on mesal suture, and small spots on posterolateral area of sclerite; posteromesal sclerite (sa 2) yellow with transverse dark area on posterior margin occupying more than one-third of sclerite, dark spot on mesal suture, and other spots on anterior margin of sclerite; lateral sclerite (sa 3) yellow with row of longitudinal dark spots and with many setae on anterior margin. Metanotum divided into 5 sclerites: Anteromesal pair of sclerites (sa 1) brown with setae on anterior margin; lateral pair of sclerites (sa 3) brown with setae on anterior and lateral margins; posteromesal sclerite (fused sa 2 sclerites) brown, transversely elongate, straight, with few setae laterally (Fig 28g). Legs yellow.
Abdomen: Abdominal gill formula as in Fig 5. Tergite IX subtriangular. Anal prolegs without teeth on external margins of claws.
Pupa: Body length 8.0– 8.33 mm (n = 2). Body brown in alcohol.
Head: Mandibles long, more than three times longer than wide, distal portion narrow, serrate on entire internal margin. Labrum subquadrate, with lateral angles rounded (Fig 28h).
Thorax: Mesotarsi each with fringe of long setae.
Abdomen: Segments III–VII with small oval anterior hook plates, each with one hook oriented posterad; segment V with 2 triangular posterior hook plates, each with one anterior and 2 posterior hooks oriented anterad (Fig 28i). Terminal processes long, slender, and divergent from base (Fig 28j).
Case: Length 5.0 mm (n = 1), composed of various small fine and coarse sand grains, slightly curved, broadening from posterior to anterior (Fig 28k).
Bionomics: This species is found in the warm, calm, and acidic waters of Rio Negro from 3,000 to 11,000 m in width, on the sandy bottom and submerged tree roots. The type locality of this species is in this same river basin. The adult behavior is not known, since the specimens collected in this work were larvae reared in the lab. The holotype described by Marlier (1964) was collected in a tributary stream (Igarapé Mentai) of the Rio Tapajós sub-basin, in clear and less acidic waters.
Distribution: BRAZIL: Amazonas, Pará, Rondônia (Fig 29).
Material examined: BRAZIL, Amazonas, Manaus: Praia da Lua, Rio Negro, 03°01’53.8”S 06°008’15.9”W, 40 m alt, raízes submersas, 28.ix.2003, A.M.O. Pes leg., 3 larvae [alcohol] (INPA-TRI 000091); 20.viii.2010, L.M. de Camargos, C. R. Santos Neto, E.A. Reis, A. Somavilla leg., 1 male, 2 larvae and their pupal exuviae (INPA-TRI 000092). Pará, Belterra: Floresta Nacional do Tapajós, Igarapé do Xibé, 03°07’04.30” S 05°503’49.50” W, 90 m alt., 21.ix.2016, A.M. Pes, J. da Silva, G. Amora, G.D. Gomes leg. Malaise trap, 1 male [alcohol] (INPA-TRI 000093). Rondônia, Guajará-Mirim: Rio Pacas Novas, Rio Novo, 11°13’38 S 64°55’15 W, 07.ix.1999, N. Hamada, R. L. Menezes leg., Malaise trap, 2 males [pinned] (INPA-TRI 000094-95).
Comments: From Marlier’s original description: C40. 12.XI.1952 Igarapé Mentai; embouchure; eau stagnate, parmi les plates submergées d’ Utricularia. (Marlier 1964) the type locality of Marilia siolii is Igarapé Mentai (The mouth of this stream is located on Lake Ateria of the Tapajós River), [Brazil, Pará, Santarém, Igarapé Mentai, mouth, approximate coordinates 02°39’58.33”S, 55°36’36.06”W].
description: Published as part of Camargos, Lucas M., Pes, Ana Maria & Hamada, Neusa, 2020, New Neotropical species of Marilia Müller (Trichoptera: Odontoceridae), pp. 1-41 in Zootaxa 4853 (1) on pages 34-39, DOI: 10.11646/zootaxa.4853.1.1, http://zenodo.org/record/4410232