Bioacoustics of Hygronemobius caxiuana

Description. Head , in frontal view, triangular, with well-developed eyes, taller than wide, as tall as half the height of the head, and the antennal orbit close to the lower margin of the eyes ( Fig. 1E ). 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. 1E ). Reticulated spots formed by dark brown punctuations, weakly interconnected, extending laterally from the lower area of the eyes across the gena to the proximal portion of the mandible ( Figs. 1D–E ). In lateral view, a shaded dark brown reticulated spot surrounds the eyes, extending from the gena to the vertex ( Fig. 1D ). Post-gena uniformly yellowish ( Fig. 1D ). Maxillary palp with the first two segments subequal, cylindrical, yellowish in color, and whitish distally; third segment longer than the two previous ones combined, subcylindrical, narrower, and whiter than the preceding and succeeding segments; fourth conical, smaller, and slightly darker than the third; fifth conical, distally rounded, longer than any previous segment, and yellowish ( Fig. 1F ). Thorax. Pronotum, in dorsal view, rectangular, with anterior and posterior margins nearly straight. Coloration light brown with irregular eye spots on the median posterior half ( Figs. 1B ; 2A ). 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 seven macrochaetae arranged in a curved line from the posterior portion of the pronotal disc eye spots to the anterolateral portion and two mesochaetae branching from the fourth macrochaeta ( Figs. 2A–B ); In lateral view, lateral lobe longer than tall, with sinuous ventral margin bearing a medial concavity and a dark triangular patch narrowing towards the anterior margin ( Figs. 1A, D ; 2A, C ). LS formed by four macrochaetae and one mesochaeta following the oblique border of the lateral lobe mark ( Figs. 2C–D ). Prosternum reduced, with concave dark brown spots; mesosternum rectangular, with rounded corners and slightly darker anterior portion; and metasternum hexagonal, with slightly darkened anterior edges. Mesosternum and metasternum setose ( Fig. 1G ). Wings. Tegmina light brown with whitish spots in the anal, postcubital, and harp regions and at the distal apex of the wing, radiating from the cubital-anal region and extending along the entire length of the medial + cubital-anal vein. Aa+PCup veins faintly visible. Tegmina oval, longer than wide ( Fig. 3A ). In lateral view, narrow and elongated, with an evident curvature in the first C+Sc vein ( Fig. 3B , white circle ). Stridulatory file with 45 teeth (N = 1, Fig. 3C ). Legs ochre, with brownish spots, conspicuous setae (macrosetae), and pubescent surface covered with small setae ( Figs. 4A–F ). All tibia and tarsi with brown spots intercalated with lither rings ( Figs. 4A–F ). First pair of legs with two spurs and with tympanum only on the outer side ( Figs. 4A–B ). Middle legs similar to the anterior ones ( Figs. 4C–D ). Hind legs robust, with three dorsal spurs on each margin, two apical on the inner margin, and three on the outer margin ( Figs. 4E–F ). Abdomen , in dorsal view, brownish with a continuous and irregular ochre macule ranging from the sixth segment to the supra-anal plate, forming a whitish triangle ( Figs. 1B ; 4G ). In ventral view, sternites dark brown, with whitish and circular spots, laterally located on the medio-distal portions of the segments ( Fig. 1C ). Supra-anal plate with widely convex posterior border ( Fig. 4G ). Subgenital plate, in ventral view, darkened, with two whitish spots on the posterolateral margin, longer than wide, with a slightly incised posterior border ( Fig. 4H ). In lateral view, longer than high, with a slightly curved ventral surface ( Fig. 4I ). Phallic complex. Pseudepiphallic apical lobes truncated and laterally covered by the median lobes ( Figs. 5A, D ); membranous distally, slightly longer than wide, hyaline, with apex bearing small setae and a brief sinus between the lobes ( Fig. 5A ); laterally barely visible, covered by the median lobe ( Fig. 5D ). Pseudepiphallic median lobes well-sclerotized and anteriorly curved, with three distal lobes ( Fig. 5A–C ). Ectophallic apodemes thin. Endophallic sclerite central part connected to lateral appendages only distally and medio-proximally clearly separated; lateral appendages heart-shaped ( Figs. 5A–B ). Endophallic apodeme reduced ( Fig. 5B ). Rami straight and thin ( Fig. 5A– B ). Ectophallic fold reduced, hyaline, and poorly sclerotized ( Fig. 5D ). Female. Wings reduced ( Fig. 6A ). Base of the pronotal disc larger than males ( Fig. 6B ). Abdominal tergites spotted in dark brown, with the lateral portion of the first tergite, the second and third, almost all the fifth, the middle part of the seven to ninth tergites, and supra-anal plat ochre, the remaining tergites spotted in brown ( Fig. 6B ). Ovipositor slightly upcurved ( Fig. 6D ), light brown ventrally, and darkening dorsally and toward the apex, which bears very small denticulations ( Figs. 6E–F ). Tenth tergite setose, very small, with rounded posterior margin and a slightly whitish spot giving the impression of a division in the tergite ( Fig. 6G ). Subgenital plate whitish, almost yellowish, and with a slightly darkened brown oval spot ( Fig. 6I ); in ventral view, wider than long and emarginated ( Fig. 6H ); in lateral view, longer than tall, with rounded posterior margin ( Fig. 6H ). Measurements (mm). Males. TL: 6.6–7.1; PL: 1.1–1.9; PW: 1.1–1.9; Tg: 2.7–3.3; HF: 3.7–4.3; HT : 2.1–3.5. Females. TL: 6.7–8.4; PL: 1.1–2.0; PW: 1.2–2.0; Tg: 0.6–1.2; HF: 3.4–4.1; HT : 3.0–3.7; Ov: 2.9–3.3.