Bioacoustics of Megasoma

1 Maxilla with 4 or 8 stridulatory teeth. Diameter of abdominal spiracles progressively enlarged posteriorly, mainly from segment V to segment VIII. Maximum width of cranium 11–18 mm - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 2 1 9 Maxilla with 5–7 stridulatory teeth. Diameter of abdominal spiracles progressively reduced posteriorly, mainly from segment V to segment VIII. Maximum width of cranium 7–9 mm - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 5 2 Bulla of spiracles transverse, raised, with acute apex ( Figs. 12–13 ). Last antennal segment with 10–14 dorsal sensory spots. Frons with 1 posterior frontal setae on each side. Dexiotorma narrow, elongate ( Fig. 2 ). Maximum width of head capsule 11.3 mm - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - M. pachecoi Cartwright 2 9 Bulla of spiracles vertical, slightly prominent, rounded ( Fig. 75 ). Last antennal segment with 8–11 dorsal sensory spots. Frons with 2–4 posterior frontal setae on each side. Dexiotorma wide, angular ( Fig. 68 ). Maximum width of head capsule 15–18 mm - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 3 3 Frons with 70–80 frontal setae. Dorsum of abdominal segment I without short, spine-like setae, only with long, slender setae. Campus with 4–6 long, slender setae - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - M. elephas (F.) 3 9 Frons with 4 or 8 frontal setae. Dorsum of abdominal segment I with mixture of long, slender setae and short, spine-like setae. Campus with 20–28 setae - - - - - - - - - 4 4 Each tarsungulus with 4 setae. Frons with 4 frontal setae. Maxilla with 8 stridulatory teeth. Last antennal segment with 8 dorsal sensory spots - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - M. occidentalis Bolívar y Peltain, Jiménez-Asffla, and Martínez 4 9 Each tarsungulus with 2 setae. Frons with 8 frontal setae. Maxilla with 4 stridulatory teeth. Last antennal segment with 11 dorsal sensory spots - - - - - - - - - M. actaeon (L.) 5 Lobes of respiratory plates of spiracles separated ( Figs. 39 , 62–63 ). Frons with 3–4 posterior frontal setae on each side. Acanthoparia with 10–14 setae - - - - - - - - - - - - - - - - - 6 5 9 Lobes of respiratory plates of spiracles contiguous or nearly so ( Figs. 26 , 53– 54 ). Frons with 5–7 posterior frontal setae at each side. Acanthoparia with 5–9 setae - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 7 6 Maxilla with 7 stridulatory teeth ( Fig.34 ). Last antennal segment with 7 dorsal sensory spots ( Fig. 36 ). Dorsa of abdominal segments I–II with mixture of long, slender setae and short, spine-like setae. Frons with 2 dorsoepicranial setae and 46 epicranial setae on each side; anterior frontal setae lacking - - - - - - - - - - - - - - - - - - - - - - - - - M. thersites LeConte 6 9 Maxilla with 4 stridulatory teeth ( Fig. 59 ). Last antennal segment with 4 dorsal sensory spots ( Fig. 61 ). Dorsa of abdominal segments I–II with only long, slender setae. Frons with 7–10 dorsoepicranial setae and 10–16 epicranial setae on each side, and with 10–11 anterior frontal setae - - - - - - - - - - - - - - - - - - - - - - - - - - M. cedrosa Hardy 7 Frons with 6–7 anterior frontal setae. Dexiotorma wide, truncate ( Fig. 44 ). Dorsum of abdominal segment I with mixture of long, slender setae and short, spine-like setae. Bulla of spiracles irregularly rounded, vaguely trilobed ( Figs. 53–54 ). Campus with 18 setae - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - M. vogti Cartwright 7 9 Frons without anterior frontal setae. Dexiotorma narrow, elongate ( Fig. 17 ). Dorsum of abdominal segment I with long, slender setae, without spine-like setae. Bulla of spiracles slightly convex, rounded ( Fig. 26 ). Campus with 28–30 setae - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - M. punctulatus Cartwright