Smicridea (Smicridea) polyacantha Desiderio, Pes & Hamada, 2021

Desiderio, Gleison Robson, Pes, Ana Maria, Andrade-Souza, Vanderly & Hamada, Neusa, 2021, The Smicridea (Smicridea) fasciatella species group (Trichoptera: Hydropsychidae) in Brazil: six new species and new distributional records, European Journal of Taxonomy 750 (1), pp. 156-196 : 179-182

publication ID 10.5852/ejt.2021.750.1371

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Smicridea (Smicridea) polyacantha Desiderio, Pes & Hamada

sp. nov.

Smicridea (Smicridea) polyacantha Desiderio, Pes & Hamada sp. nov.

Figs 3 View Fig , 4F View Fig , 13 – 14 View Fig View Fig


This new species is a distinct member of the fasciatella group due the presence of small endothecal spines on the apex of the phallic apparatus. Smicridea polyacantha sp. nov. and S. paranensis are the sole species in the group that share this character. However, the new species has 40 conical endothecal spines grouped in a V-shaped arrangement in dorsal view, while S. paranensis has numerous fine spines organized in four rows. Additionally, the apex of the apical segment of the inferior appendage is rounded in the new species and obliquely truncated in S. paranensis . The phallotremal sclerite has a proximal region that is bifid, curved downward in lateral view, and a dorsolateral projection on the distal region that is unique in S. polyacantha sp. nov.


The specific epithet is an allusion to the large number of endothecal spines present on the apex of the phallus. Derived from the Greek words, ʻ poly ʼ = ʻveryʼ or ʻmanyʼ and ʻ akantha ʼ = ʻspineʼ.

Material examined

Holotype BRAZIL • ♂; Amazonas, Manaus, BR–174, Balneário Km 18.5; 02°49′00.80″ S, 60°02′05.60″ W; 33 m a.s.l.; 27 Oct. 2009; A.M.O. Pes, J.O. Silva and R. Boldrini leg.; white sheet with an LED light; INPA-TRI 000117 . GoogleMaps

Paratypes BRAZIL • 18 ♂♂; same collection data as for holotype; INPA-TRI 000118 GoogleMaps 1 ♂; same collection data as for holotype; 7 Apr. 2009; INPA-TRI 000119 GoogleMaps 2 ♂♂; same collection data as for holotype; 22 Jan. 2009; DZRJ GoogleMaps 3 ♂♂; same collection data as for holotype; Nov. 2012; DZUP GoogleMaps 5 ♂♂; Novo Airão, Igarapé Mato Grosso; 02°49′03.8″ S, 60°55′47.1″ W; 24–26 Nov. 2014; R.L.F. Keppler and J.O. Silva leg.; Pennsylvania trap; MZUSP GoogleMaps 1 ♂; Mato Grosso, Sapezal, MT–235, Rio Papagaio , outside indigenous reserve; 13°33′39.5″ S, 58°24′24.2″ W; 473 m a.s.l.; 31 Oct.–1 Nov. 2012; N. Hamada and J.M.C. Nascimento leg.; Pennsylvania trap; INPA-TRI 000120 GoogleMaps .


Adult male ( Figs 13–14 View Fig View Fig )

FOREWING LENGTH. 3.61–4.02 mm (mean = 3.79, SD = 0.15, n = 6).

COLOR. General color dark brown (in alcohol) ( Fig. 13A View Fig ). Antennae yellowish brown ( Fig. 13A View Fig ). Head dark brown, with brown setae on dorsum ( Fig. 13B–C View Fig ); dorsally with weakly pronounced median suture; with five setal warts; anteromesal wart small, rounded; anterolateral pair undivided, weakly delimited; posterolateral pair large, ovoid ( Fig. 13C View Fig ). Maxillary palp with segments 1–4 increasing gradually about 0.8× in size toward more apical segments, segment 5 long, about 1.2× as long as all previous segments combined ( Fig. 13B View Fig ). Thorax dark brown, covered with pale-brown setae; legs brown, with mid-leg tarsi yellowish ( Fig. 13A View Fig ). Wing venation typical for subgenus ( Fig. 13D–E View Fig ). Forewings, in alcohol, brown, with white transverse band subapically on pterostigma reaching base of R4+5 and small white spot on apex of Cu2 ( Fig. 13D View Fig ). Sternum V with anterolateral glandular processes slightly shorter than sternum. Abdominal segments VI and VII with 2 pairs of internal glands, both pairs as long as their containing segments ( Fig. 13F View Fig ).

MALE GENITALIA ( Fig. 14 View Fig ). Segment IX in lateral view with anterolateral margin nearly straight, weakly sclerotized ( Fig. 14A View Fig ); posterodorsal margin bearing small spicules, distributed in two rounded bands ( Fig. 14B View Fig ). Tergum X elongate; in lateral view, ventrolateral margin slightly sclerotized, with five long, thin setae on apical third; apex produced and upturned ( Fig. 14A View Fig ); in dorsal view, lateral margin straight; dorsomesal setose area bearing two medium-sized, thin setae; divided apicomesally by a V-shaped incision about ½ its length; apex of tergite slightly pointed, with small apicomesal lobe and about six mediumsized, thin setae ( Fig. 14B View Fig ). Inferior appendages 2-segmented; basal segment long, slightly inflated distally, covered with medium-sized, thin setae, with one long, stout subapical spine-like seta on mesal margin; apical segment short, about ⅓ as long as basal segment, thick, slightly curved medially, apex rounded with numerous short, thin setae on mesal margin ( Fig. 14B View Fig ). Phallic apparatus long and tubular; basal section, in lateral view, enlarged, 3× diameter of phallotheca at its narrowest point, forming an angle of about 116° with apical section; median section of phallotheca straight, with dorsal periphalic cap sclerotized, slender and upturned ( Fig. 14C View Fig ); apex slightly enlarged, without processes or plates; endothecal membranes with 40 small, conical spines, grouped in a V-shaped arrangement and directed posterad; phallotremal sclerite, in dorsal view, distinct, strongly sclerotized, proximal region bifid, curved downward in lateral view and directed posterad, distal region with dorsolateral projections more than half length of sclerite, broad apically, folding and touching dorsomesally, and with another pair of slender ventrolateral projections curved downward and directed anterad ( Fig. 14D–E View Fig ); in lateral view, proximal and distal regions hooked, not parallel in proximal region ( Fig. 14C View Fig ). Ejaculatory duct of endophallus, in lateral view, indistinct ( Fig. 14C View Fig ). When endothecal membranes are everted, phallotremal sclerite modified into two dorsolateral slender lobes, forked at apex, connected to a dorsomesal ring, and apical spines divided into two lateral lobes with 20 spines each, in lateral view, directed anterad ( Fig. 14F–G View Fig ).


This species was collected near medium-sized streams with slow flow in central Amazonia. The streams were strongly impacted by human activities, especially recreational use (swimming) and road building ( Fig. 4F View Fig ). These streams have sandy bottoms and are characterized by Dense Ombrophilous Forest Lowlands to Dense Ombrophilous Forest. Only one male of S. polyacantha sp. nov. was collected near a large river (Rio Papagaio) with fast-flowing water and a rocky bottom, located in the western part of the Brazilian Cerrado, where the vegetation is composed by Primary Savanna, Seasonal-Forest Savanna, and Wooded Savanna. The surroundings of this region are also strongly impacted by agricultural and pasture activities.

Distribution ( Fig. 3 View Fig )

Brazil: Amazon (Amazonas), Cerrado (Mato Grosso).


Brazil, Parana, Curitiba, Universidade Federal do Parana, Museu de Entomologia Pe. Jesus Santiago Moure


Universidade Federal do Parana, Colecao de Entomologia Pe. Jesus Santiago Moure


Museu de Zoologia da Universidade de Sao Paulo













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