Bioacoustics of Bothynus stenelus

Redescription . Male . Body length : 22.0–28.0 mm. Body width : 10.0–14.0 mm. Color : From dark brown to reddish brown, with red or reddish-brown spotted areas when viewed with bright light ( Fig. 2 A–C). Head : Clypeus subpentagonal, 2.5 times wider than long, strongly rugopunctate, usually glabrous. Frontoclypeal suture with 2 strong, transverse, oval shaped tubercles. Interocular width equals 3.0 transverse eye diameters, frontal surface strongly rugopunctate. Eye canthus rectangular. Mouthparts : Mandibles tridentate; apical and medial teeth triangular, basal tooth small, lobed. Maxilla with tridentate galea; apical and medial teeth strong, basal tooth weak. Mentum with weakly punctate discal area, basal area sometimes with 2 longitudinal sulci. Pronotum : Strongly convex posteriorly in lateral view ( Fig. 2B ); apical tubercle conic, moderate in size, rounded at apex; concavity broad, deep, occupying nearly 1/2 of pronotal area in major and median males ( Fig. 2A ), and 1/ 3 in minor males ( Fig. 2C ); edge around the concavity with 2 weakly marked, dorsal contractions; lateral borders barely visible in dorsal view; posterior angles backward projected; surface of tubercle basis with dense, coalescent, C-shaped punctures; concavity densely rugopunctate, rarely completely rugose in major males. Legs : Protarsomere IV with ventral apex prolonged, nearly reaching the apex of ventro-basal tooth of tarsomere V ( Fig. 2E ); inner claw with rounded outer edge. Metatrochanter with rounded apex ( Fig. 2F ). Metatibiae usually with an incomplete basal carina; inner spur spatulate. Abdomen : Ventrite I completely setose, II setose only on sides, III–V with an incomplete row of setose punctures, disc glabrous, VI bordered with setae on apex. Tergite VII with stridulatory apparatus formed by two bands of barely marked carinae, interrupted by a mid-line near to basal margin. Tergite VIII usually glabrous, occasionally with few setae on sides, rugopunctures confined on sides, disc smooth. Aedeagus : Parameres in caudal view ( Fig. 8B ), outer sides nearly subparallel, apical half with lateral “flaps” less expanded than basal half. In lateral view, apex shortened, downcurved ( Fig. 9B ). Female ( Fig. 2D ). Body length : 22.0–28.0 mm. Body width : 12.0–15.0 mm. Female differs from male in in the following aspects: Head : Frontoclypeal tubercles usually barely marked. Pronotum : Weakly convex, apical tubercle and concavity obsoletes, surface densely punctate on sides, becoming weak on disc ( Fig. 10B ). Legs : Inner protarsal claw simple, similar to outer claw. Abdomen : Ventrite VI triangular. Tergite VIII with rounded apical invagination, 3.2 times wider than long ( Fig. 11B ). Geographic distribution . Brazil : Minas Gerais , Rio de Janeiro , São Paulo , Paraná , Santa Catarina ( Fig. 12B ). Bothynus stenelus is endemic to the Brazilian Atlantic coastal rainforest of the southeastern and southern regions.