Oecetis amplicauda Quinteiro & Saldanha, 2025

Oecetis amplicauda Quinteiro & Saldanha sp. nov.

Figs 1 View Figure 1 , 2 View Figure 2 , 3 View Figure 3

Type locality.

Brazil, Pará: Bragança, Jiquiri, ramal Arauá, Sítio Cururutuia, 01°04'42.22"S, 46°44'14.58"W, alt 19 m.

Type material.

Holotype: Brazil • ♂; Pará, Bragança, Jiquiri, ramal Arauá, Sítio Cururutuia ; 01°04'42.22"S, 46°44'14.58"W; alt 19 m; 16 Apr. 2021; light trap; F. B. Quinteiro & A. M. Costa leg.; MNRJ -ENT 10-362 GoogleMaps . Paratypes: # 1 ♂; same data as for holotype; UFBA T 1859 GoogleMaps • 1 ♂; same as for holotype MPEG.HEX 05040018 GoogleMaps • 1 ♂; same as for holotype, except 15 May 2021; MPEG.HEX 05040019 GoogleMaps • 1 ♂; same as for holotype, except 11 Apr. 2022; MPEG.HEX 05040020 GoogleMaps .

Diagnosis.

Due to the honeycomb microstructure covering terga V – VIII, this species belongs to the O. testacea species group as defined by Quinteiro and Holzenthal (2017). It can be distinguished from other species in this group by having the dorsal portion of tergum X longer than the preanal appendage, cylindrical, and with an acute apex in dorsal view. Also, the inferior appendage has an enlarged basis and a rounded dorsal lobe which bears short, thick setae, and with an inward-directed apex.

Description.

Male. General color yellowish brown in alcohol (Fig. 1 A View Figure 1 ). Forewing length 5.0– 5.9 mm, ( n = 4), holotype 5.2 mm. Hindwing length 4.0– 4.9 mm ( n = 4), holotype 4.8 mm.

Head yellowish brown (Fig. 1 A View Figure 1 ). Antennae three times length of forewing; scape stout; pedicel short. Anteromesal setal wart small, rounded; posterior setal wart rounded; posterolateral setal wart thin. Maxillary palps yellowish brown, 5 - segmented (Fig. 1 A View Figure 1 ); labial palps yellowish brown, 3 - segmented (Fig. 1 A View Figure 1 ).

Thorax. Pterothorax brown. Forewings yellowish brown (Fig. 1 A, B View Figure 1 ); dark bands present on forewing over chord ( s, r-m, m-cu); dark spots present on forks, junctions, and vein tips; colored setae absent; forks I and V present, both rooted; sectoral crossvein ( s) distal of r-m; m-cu crossvein basal of r-m (Figs 1 B View Figure 1 , 2 A View Figure 2 ). Hindwings yellowish brown; forks I and V present (Figs 1 C View Figure 1 , 2 B View Figure 2 ). Legs yellowish brown. Tibial spur formula 1, 2, 2; foreleg tibial spur ½ length of mid- and hindleg spurs.

Abdomen. Reticular patches (honeycomb texture, Fig. 1 D, E View Figure 1 ) on terga V – VIII. Acrotergite present between segments VIII and IX (Figs 1 D, E View Figure 1 , 2 C, D View Figure 2 ). Segment IX short, medially enlarged and posterolateral process absent in lateral view (Figs 1 D View Figure 1 , 2 C View Figure 2 ); wider than inferior appendages in ventral view, with anterior margin concave (Figs 1 F View Figure 1 , 2 E View Figure 2 ). Preanal appendages short, apex rounded, basally broadened in lateral view, with apical setae (Figs 1 D View Figure 1 , 2 C View Figure 2 ), ovate, with round base and acuminate apex in dorsal view (Figs 1 E View Figure 1 , 2 D View Figure 2 ). Tergum X longer than preanal appendage, dorsoventrally divided in lateral view (Figs 1 D View Figure 1 , 2 C View Figure 2 ); dorsal portion slightly longer than ventral, tapering apically, with apex acuminate, ventral portion mesally divided, basally broadened, apex rounded in dorsal view (Figs 1 E View Figure 1 , 2 D View Figure 2 ). Inferior appendage 1 - segmented, setose, basally enlarged; dorsal lobe enlarged, apex rounded, projecting dorsad, with stout, short setae in lateral view (Figs 1 D View Figure 1 , 2 C View Figure 2 ); ventral lobe absent (Figs 1 D – F View Figure 1 , 2 C – E View Figure 2 ); distal lobe concave, smoothly apically tapering, apex acuminate, slightly curved inward, obtuse angle formed by dorsal and distal lobes (Figs 1 D – F View Figure 1 , 2 C – E View Figure 2 ). Phallic apparatus symmetrical, elongate, cylindrical, ventrally bent; phallobase basally large, sclerotized, slightly constricted subasally (Figs 1 D View Figure 1 , 2 F, G View Figure 2 ); endotheca twice as long as phallobase and 1 - lobed in lateral view (Figs 1 D View Figure 1 , 2 F View Figure 2 ), same length in ventral view (Fig. 2 G View Figure 2 ); phallic spines absent; phallotremal sclerite absent (Figs 1 D View Figure 1 , 2 F, G View Figure 2 ).

Female and immatures. Unknown.

Etymology.

amplio (Latin) = enlarged; cauda (Latin) = tail, appendage. The species name is a reference to the enlarged inferior appendages, with a prominent dorsal lobe.

Distribution.

Known only from the type locality in Pará state, Brazil (Fig. 3 View Figure 3 ).

Taxonomic remarks.

Oecetis amplicauda sp. nov. belongs to the O. testacea group of Quinteiro and Holzenthal (2017) due to the honeycomb-like texture on the abdominal terga. It is the fourth species described, along with O. iara Henriques-Oliveira, Dumas & Nessimian, 2014 , O. plenuspinosa Quinteiro & Holzenthal, 2017 , O. meronai Gibon, 2019 , and O. ancorospina Moura & Quinteiro, 2023 . Among the O. testacea - group species, it is most similar to O. ancorospina Moura & Quinteiro, 2023 . These two species share a rounded preanal appendage, a long, cylindrical dorsal portion of tergum X, and an elongate phallic apparatus. However, the new species has segment IX slightly medially enlarged in lateral view, with no anterior or posterolateral projections. In O. ancorospina , segment IX has a distinct projected anterolateral margin and presents a posterolateral projection. The inferior appendages in O. amplicauda sp. nov. are basally enlarged and with a distinct dorsal lobe, while in O. ancorospina , the inferior appendages are basally constricted. Also, the distal lobe of the inferior appendages in O. ancorospina is large, with a truncate apex, while in O. amplicauda sp. nov., they taper distally, with an acuminate apex, which is bent inwards. Additionally, O. amplicauda sp. nov. is the only known species in the O. testacea - group that has no phallotremal sclerite or phallic spine.