Bioacoustics of Ceratochodaeus darlingi

Description. Holotype male ( Fig. 1–3 , 6–9 ). Coleoptera : Scarabaeoidea: Ochodaeidae . Length: 10.6mm (from the apex of the mandibles to the apical part of the tergite VIII). Width: 5.9 mm. Head: Transverse, sub-hexagonal, dark reddish-brown, gradually narrowed behind the eyes. Surface shiny, long pubescent, the setae obliquely directed backwards; surface microreticulate with medium setiferous granules separated from each other by a distance substantially equal to their diameter. Labrum transverse, dorsally convex, hyaline, long pubescent, strongly emarginate in the middle front. Eyes large, globose, strongly produced laterad. Anterior clypeal membrane transverse, trapezoidal, in thin tegumentary plate overhanging the labrum. Frontoclypeus elevated, obliquely sloping forward, arched rearward, surmounted by a strong sub-pyramidal horn, abruptly truncated at apex. In upper view, the truncation delineates a transverse, concave, kidney-shape area ( Fig. 6 ). Mandibles subequal, falciform, slightly concave dorsally, the apex and outer edge distinctly darkened. Mentum oblong, subquadrangular, emarginate and weakly depressed in front, the surface finely microreticulate, pubescent along the lateral margins (see Fig. 7 ). Antenna 10-segmented, 3-antennomere club, testaceous, shiny, the outer club segment distinctly brightened and pubescent at the upper edge. Pronotum transverse, strongly convex, the lateral edges and base fringed with setae, the outline entirely margined, the marge distinctly widening in the middle of the base forming a transverse bulge in an portion extending on both sides up to the level of the humeral callus. Anterior margin deeply emarginate behind the head, with a thin hyaline membrane in front. Front angles obtuse, projecting forward, the posterior ones regularly rounded. A short median longitudinal furrow at base, not reaching the middle forward. Pronotal surface densely granulate; granules shiny, setose, the setae obliquely directed anteriorly; surface shiny, bicolored, dark reddish brown with two orange-colored lateral areas and a distinct darkened fovea in the middle of each side; a longitudinal orange-colored medio-discal macule not reaching the anterior edge in front. Elytra transverse, their color coarsely similar to that of the pronotum with two rows of orange transverse patches. The first row located at the ¼ front, the second one located behind the middle ( Fig. 1, 3 ). The anterior band extending from interstria II to VII, interrupted on interstria III. The second row, arranged in staggered orange spots, extending from interstria II to VII. Surface with well impressed striae, consisting of sunken medium points, separated by 1.5 to 2 x their diameter; elytral punctuation strong and tight consisting of small setose granules on a microreticulate background, the minute setae oriented backward. Humeral callus well developed; a second callus present in the apical declivity at the level of the 5th and 6th interstriae. Scutellum in elongated triangle, the lateral edges slightly convex, the surface with few scattered setose medium punctures. Abdomen strongly convex with six visible sternites (III–VIII). Surface smooth, with few scattered minute setose granules. The anterior margin of each sternite with a line of coarse granules bearing long setae, distant from each other by at least 1× their diameter. A median process originating on the sternite IV as a convex bulge, extending backwards, ending acutely at the level of the penultimate sternite (sternite VII) (this feature is absent in females). This process, asymmetrical, is located, in ventral view, on the left side, flanked on either side by a strong longitudinal depression, this depression clearly more marked on the right side. Tergite VIII (pygidium) pubescent, the punctuation consisting of small close granules embedded on a microreticulate background. Metasternal process subplanar with a thin median darkened groove in the anterior half; mesocoxae widely separated. Stridulatory apparatus (sternite VI) present. Legs: Protibia quadridentate externally, the median tooth barely visible, the basal tooth very reduced; internal side with a strong acute pollex obliquely directed forward, darkened apically. Femurs without accessory teeth, their surface with two parallel rows of setose punctures. Upper spur of metatibia of equal length to that of the first metatarsus. Genitalia: Aedeagus with elongated phallobase, curved dorsoventrally, acuminate apically; parameres short, symmetrical, distinctly divergent at apex. Endophallus well developed with two main sclerites ( Fig. 9 ) and two barely perceptible accessory sclerites. Sexual dimorphism. As described for the genus, namely the presence, in males, of a strong frontoclypeal horn, truncated apically ( Fig. 1, 3 , 6 ) [the female with a single arched carina ( Fig. 4–5 )], the pronotum more convex dorsoventrally, and by the presence of a median abdominal apophysis acuminate posteriorly (absent in females).