Smicridea (Smicridea) brevitruncata 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 : 164-168

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

urn:lsid:zoobank.org:act:47DD9364-4029-4B7C-A3EC-08B52BC03778

Figs 3 , 4B , 5 – 6

Diagnosis

Smicridea brevitruncata sp. nov. belongs to the albosignata complex of Flint (1981). It is most similar to S. riita Flint, 1981 from Venezuela based on the obliquely truncated apex of tergite X in dorsal view. However, in S. brevitruncata sp. nov. the apical segment of the inferior appendage is thick and short, and the truncated apex has numerous medium-sized, acuminate setae on the mesal margin, whereas in S. riita it is long, slender, with an acute apex, bearing numerous short, thin setae. Furthermore, the new species can be diagnosed by the basal segment of the inferior appendage having four long, stout apical spine-like setae, two dorsal and two on the mesal margin, and by the shape of the phallotremal sclerite, mainly in dorsal view. Additionally, S. brevitruncata sp. nov. differs from all other species of S. ( Smicridea ) by the absence of the internal reticulate sacs on abdominal segments VI and VII.

Etymology

The specific epithet is an allusion to the characteristics of the inferior appendages, which are short and apically truncated. Derived from the Latin words, ʻ brevi ʼ = ʻshortʼ and ʻ truncata ʼ = ʻpiece cut off, tip, endʼ.

Material examined

Holotype BRAZIL • ♂; Santa Catarina, Ponte Serrada , BR–282, Rio Irani , Parque dos Butieiros ; 26º55′49.2″ S, 51º52′29.3″ W; 1022 m a.s.l.; 5 Sep. 2009; N. Hamada, A.M.O. Pes and J.O. Silva leg.; white sheet with an LED light; INPA-TRI 000108 .

Paratypes BRAZIL • 8 ♂♂; same collection data as for holotype; INPA-TRI 000109 • 2 ♂♂; same collection data as for holotype; DZUP • 2 ♂♂; same collection data as for holotype; DZRJ • 2 ♂♂; same collection data as for holotype; MZUSP .

Description

Adult male ( Figs 5–6 )

FOREWING LENGTH. 4.52–5.49 mm (mean = 4.75 mm, SD = 0.37, n = 5).

COLOR. General color dark brown (in alcohol) ( Fig. 5A ). Antennae brown ( Fig. 5A ). Head dark, with grayish to black setae on dorsum ( Fig. 5B–C ); dorsally with slightly pronounced median suture; with five setal warts; anteromesal wart small, rounded; anterolateral pair undivided, weakly delimited; posterolateral pair large, ovoid ( Fig. 5C ). 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. 5B ). Thorax dark brown, covered with brown setae; legs brown, with mid-leg tarsi yellowish ( Fig. 5A ). Wing venation typical for subgenus ( Fig. 5D–E ). Forewings, in alcohol, uniformly fuscous, faintly marked with transverse band subapically on pterostigma reaching base of R4+5 and small spot on apex of Cu2 ( Fig. 5D ). Sternum V with anterolateral glandular processes slightly shorter than sternum. Abdominal segments VI and VII without pairs of internal reticulate sacs ( Fig. 5F ).

MALE GENITALIA ( Fig. 6 ). Segment IX in lateral view with anterolateral margin straight, strongly sclerotized ( Fig. 6A ); posterodorsal margin bearing small spicules, distributed in two subtriangular bands ( Fig. 6B ). Tergum X elongate; in lateral view, ventrolateral margin strongly sclerotized, with 10 to 12 short, stout setae on apical third; apex produced and upturned ( Fig. 6A ); in dorsal view, lateral margin slightly rounded; dorsomesal setose area bearing 10 medium-sized, thin setae; divided apicomesally by V-shaped incision about ⅓ its length; apex of tergite obliquely truncated, with about three short, thin setae ( Fig. 6B ). Inferior appendages 2-segmented; basal segment long, slightly inflated distally, covered with long, thin setae, with four long, stout apical spine-like setae, two dorsal and two on mesal margin; apical segment short, about ¼ as long as basal segment, thick, slightly curved medially, apex truncated with numerous medium-sized, acuminate setae on mesal margin ( Fig. 6B ). Phallic apparatus long and tubular; basal section, in lateral view, enlarged, 4× diameter of phallotheca at its narrowest point, forming an angle of about 113° with apical section; median section of phallotheca straight, without processes ( Fig. 6C ); apex enlarged, with pair of claw-shaped internal dorsolateral plates, longer than basal width, curved mesally and directed posterad; endothecal membranes without spines; phallotremal sclerite, in dorsal view, distinct, strongly sclerotized, proximal region with bifid base and pointed apex, distally with pair of subtriangular, toothlike structures, which are overlapped by pair of slender, curved mesad processes ( Fig. 6D–E ); in lateral view, proximal region with small middorsal lobe, distally directed downward ( Fig. 6C ). Ejaculatory duct of endophallus, in lateral view, distinct, slightly sclerotized ( Fig. 6C ).

Bionomics

This species was collected near a large fast-flowing river about 20 m wide, located at 1022 m a.s.l. in the southern part of the Brazilian Atlantic Forest ( Fig 4B ). In this region the predominant vegetation is Mixed Ombrophilous Forest composed mainly of Araucaria angustifolia (Bertol.) Kuntze (Araucariaceae) , with intense agricultural and pasture activities.

Distribution ( Fig. 3 )

Brazil: Atlantic Forest (Santa Catarina).

Figures

Fig. 3. Geographical distribution map for the new species of Smicridea McLachlan, 1871 treated in this study.

Fig. 4. Habitats of the new species of Smicridea McLachlan, 1871 treated in this study: A. First-order stream, Amazonas, Brazil, collection site of Smicridea (Smicridea) blahniki Desiderio, Pes & Hamada sp. nov. B. Rio Irani, Santa Catarina, Brazil, collection site of S. (S.) brevitruncata Desiderio, Pes & Hamada sp. nov. C. Arroio Lajeado, Rio Grande do Sul, Brazil, collection site of S. (S.) caaguara Desiderio, Pes & Hamada sp. nov. holotype. D. Cascata Raddatz, Arroio Teotônica, Rio Grande do Sul, Brazil, collection site of S. (S.) caaguara sp. nov. paratype. E. Igarapé Ipiranga, Amazonas, Brazil, collection site of S. (S.) ipiranga Desiderio, Pes & Hamada sp. nov. F. Balneário Km 18.5, Amazonas, Brazil, collection site of S. (S.) polyacantha Desiderio, Pes & Hamada sp. nov.

Fig. 5. Smicridea (Smicridea) brevitruncata Desiderio, Pes & Hamada sp. nov., holotype, ♂ (INPA-TRI 000108). A. Lateral habitus (in alcohol). B. Head, right lateral view. C. Head, dorsal view. D. Forewing, right dorsal view. E. Hind wing, right dorsal view. F. Abdomen, ventral view. Scale bars in mm: A = 2; B–C = 0.5; D–F = 1.

Fig. 6. Smicridea (Smicridea) brevitruncata Desiderio, Pes & Hamada sp. nov., male terminalia, holotype (INPA-TRI 000108). A. Terga IX, X and inferior appendages, lateral view. B. Same, dorsal view. C. Phallic apparatus, lateral view. D. Apex of phallic apparatus, dorsal view. E. Apex of phallic apparatus (photograph). Scale bars in mm: A–C = 0.1; D–E = 0.05.