Hygronemobius minor Santos, Cadena-Castañeda & Tavares, 2025

Hygronemobius minor Santos, Cadena-Castañeda & Tavares sp. nov.

urn:lsid:zoobank.org:act:D3D89178-BBED-4D8F-B722-9DCCFF46E9AB

( Figs. 7–12 View FIGURE 7 View FIGURE 8 View FIGURE 9 View FIGURE 10 View FIGURE 11 View FIGURE 12 , Map 1)

Etymology: The specific epithet minor is a Latin comparative adjective meaning “smaller” or “lesser.” The name refers to the tiny size of the species.

Type material. Holotype. Male. Brasil [ Brazil], Pará, Juruti, Mutum, próx. Igarapé Mutum [next to Mutum stream]; 02°36'45.7"S, 56°11'38.2"W; 8–15.X.2006; D.F. Candiani & N.F. Lo-Man-Hung leg.; Pitfall. Repository: MPEG. GoogleMaps

Paratypes. 6 males and 4 females. Same data as the holotype, but VIII.2006 ( MPEG) GoogleMaps . 1 female. Brasil [ Brazil], Amazonas, Coari, Porto Urucu— Base de Operações Geólogo Pedro de Moura. , Área J 19; 04°52'07.6"S, 65°15'56.6"W; 01.X.2004; Bonaldo, A. & Candiani, D. leg.; Pitfall. ( MPEG) GoogleMaps .

Diagnosis. This species belongs to the species group benoisti because it has flat and large pseudepiphallic apical lobes, which are located on the dorsal face of the pseudepiphallus and are badly separate from the pseudepiphallic sclerite. In fact, the limits between the apical lobes, medial lobes, and pseudepiphallic sclerite are indistinguishable, and they are entirely sclerotized, a characteristic unique to H. minor sp. nov. ( Figs. 11A–D View FIGURE 11 ). The females have the first (except the anterior portion), second, third, and middle parts of the fifth and sixth tergites lighter ( Fig. 12B View FIGURE 12 ), more similar to H. caxiuana sp. nov. Another similar species is H. diplagion , but only the second and third tergites are lighter in this species. The ovipositor is very short and slightly upcurved ( Figs. 12D–F View FIGURE 12 ).

Description. Head, in frontal view, triangular, with eyes taller than wide; antennal orbits located close to the lower base of the eyes; genae short and spotted in brown ( Fig. 7E View FIGURE 7 ). In lateral view, vertex oblique and frons rounded; eyes taller than wide ( Fig. 7D View FIGURE 7 ). In dorsal view, occiput with a brown stripe connecting both eyes ( Fig. 7B View FIGURE 7 ). Coloration of the cephalic capsule similar in tone to the clypeus and labrum (slightly lighter), with a mixed pattern of light and dark brown ( Fig. 7E View FIGURE 7 ). Maxillary palp with first two segments equal in size, the third as long as both previous together, the fourth shorter than the third and conical in shape, and the fifth longer than any previous segments, with the apex truncated and whitish; coloration mainly ochre, with more intense tones distally, especially in the last segment, except for its lighter apex ( Fig. 7F View FIGURE 7 ).

Thorax. Pronotum, in dorsal view, rectangular, almost as long as wide, with rounded lateral margins; pronotal disc spotted with elliptical marks on the median portion of the anterior half, irregular brown marks on the dorsolateral portion and the macrochaeta insertions, and with two lighter eye spots on the median portion of the posterior half ( Figs. 8A–B View FIGURE 8 ); AS formed by three almost parallel macrochaetae; MSG formed by three macrochaetae, being two almost parallel and one obliquely positioned to the middle one; PS formed by eight or nine macrochaetae and two mesochaetae, four macrochaetae positioned behind the eye spots on the median posterior half, followed by two mesochaetae branching from the fourth macrochaeta and other four or five macrochaetae obliquely positioned from the posterior to the anterolateral portion ( Figs 8A–D View FIGURE 8 ). In lateral view, pronotum longer than tall, with a slightly convex dorsal surface ( Figs. 8C–D View FIGURE 8 ); lateral lobes with sinuous ventral margin bearing a medial concavity and a dark triangular mark narrowing towards the anterior margin ( Figs. 8C–D View FIGURE 8 ). LS formed by five macrochaetae following the oblique border of the lateral lobe mark ( Figs. 8C–D View FIGURE 8 ). Prosternum reduced; mesosternum rectangular, with rounded corners and slightly darker anterior portion; and metasternum hexagonal, with slightly darkened anterior edges. Mesosternum and metasternum setose ( Fig. 7G View FIGURE 7 ).

Wings. Tegmina oval, longer than wide, reaching up to the fourth tergite, light brown, with whitish spots in the anal, postcubital, and harp regions and at the distal portion, starting from the cubito-anal region and radiating along the entire extension of the medial + cubito-anal vein. An+PCup veins well visible ( Fig. 9A View FIGURE 9 ). First branch of C+Sc proximally curved. In lateral view, with third and fourth branches of C+Sc connected proximally ( Fig. 9B View FIGURE 9 , white circles). Stridulatory file with 36 teeth (N=1, Fig. 9C View FIGURE 9 ).

Legs ochre with brownish spots, conspicuous setae (macrosetae), and pubescent surface covered with small setae ( Figs. 10A–F View FIGURE 10 ). All tibia and tarsi with brown spots intercalated with lither rings ( Figs. 10A–F View FIGURE 10 ). First pair of legs with two spurs and a tympanum only on the outer surface ( Figs. 10A–B View FIGURE 10 ). Middle legs similar to the anterior ones ( Figs. 10C–D View FIGURE 10 ). Hind legs robust, with three dorsal spurs on each margin, two apical on the inner margin, and three on the outer margin ( Figs. 10E–F View FIGURE 10 ).

Abdomen, in dorsal view, dark brown with reticulated spots ( Fig. 7B View FIGURE 7 ). In ventral view, sternites dark brown, with whitish and circular spots, located on the distolateral edges of the segments ( Fig. 7C View FIGURE 7 ). Supra-anal plate very small, almost squared, with irregular posterior border ( Fig. 10G View FIGURE 10 ). Subgenital plate, in ventral view, dark brown, longer than wide, and slightly incised medially ( Fig. 10H View FIGURE 10 ); in lateral view, longer than high, with a slightly curved ventral surface ( Fig. 10I View FIGURE 10 ).

Phallic complex. Apical lobe completely sclerotized, with apices curved inward and posterior border oblique, bearing denticulations ( Figs. 11A–B View FIGURE 11 ). Pseudepiphallic sclerite with at least six conspicuous setae ( Fig. 11A View FIGURE 11 ). Pseudepiphallic sclerite, apical lobe, and median lobe completely sclerotized, with limits inconspicuous ( Figs. 11A–D View FIGURE 11 ). Pseudepiphallic parameres, in ventral view, as well-sclerotized inward lobes ( Fig. 11B View FIGURE 11 ). Ectophallic fold very reduced and almost inconspicuous ( Figs. 11B–D View FIGURE 11 ). Ectophallic apodeme thin, and endophallic cavity reduced ( Figs. 11A–B View FIGURE 11 ). Endophallic sclerite asymmetrical, with central part connected to lateral appendages only distally and medio-proximally clearly separated; lateral appendages heart-shaped ( Figs. 11A–B View FIGURE 11 ). Endophallic apodeme well-sclerotized and oval-shaped ( Figs. 11A–B View FIGURE 11 ). Rami almost straight, well-sclerotized, and not fused to the pseudepiphallic sclerite ( Figs. 11A–B, C View FIGURE 11 ). In axial view, apical lobe curved downward, almost imperceptible ( Fig. 11C View FIGURE 11 ). Pseudepiphallic medial lobe hyaline and with rounded apices ( Fig. 11C View FIGURE 11 ). Pseudepiphallic parameres with convex inner margin and rounded apex ( Fig. 11C View FIGURE 11 ). In lateral view ( Fig. 11C View FIGURE 11 ), pseudepiphallic apical lobe slightly downcurved. Pseudepiphallic medial lobe sclerotized.

Female. Tegmina reduced, with ventral half brown ( Fig. 12A, B View FIGURE 12 ). Abdominal tergites spotted in dark brown, with the posterior portion of the first tergite, the second and third, and the middle portion of the fifth and sixth lighter, mainly ochre ( Fig. 12B View FIGURE 12 ). Ovipositor very small, slightly upcurved ( Fig. 12D View FIGURE 12 ), with apex bearing very small denticulations ( Figs. 2E–F View FIGURE 2 ). Supra-anal plate setose, small, and widely rounded ( Fig. 12G View FIGURE 12 ). Subgenital plate whitish, almost yellowish, hyaline, with a slightly darkened brown oval spot ( Fig. 12I View FIGURE 12 ); in ventral view, wider than long and emarginated ( Figs. 12H View FIGURE 12 ); in lateral view, almost as long as tall, with rounded convex posterior margin ( Fig. 12H, I View FIGURE 12 ).

Measurements (mm).

Males. TL: 5.9–6.8; PL: 1.2–2.0; PW: 1.5–2.5; Tg: 2.4–3.4; HF: 3.4–4.6; HT: 2.5–3.6.

Females. TL: 5.6–6.6; PL: 1.0–1.5; PW: 1.4–1.8; Tg: 0.7–1.2; HF: 3.4–4.1; HT: 2.6–3.1; Ov: 2.3–2.9.

Distribution. This species is recorded in two localities: Juruti, Pará State (type locality) and Coari, Amazonas State (Map 1).