Megasoma Kirby 1825
Creators: name: Ratcliffe, Brett C.
name: Morón, Miguel-Angel
Publisher: name: Zenodo
Year: 2005
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Dynastidae
Megasoma

description: Key to the Third Instar Larvae of Megasoma in North and Central America   
 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
description: Published as part of Ratcliffe, Brett C. & Morón, Miguel-Angel, 2005, Larval Descriptions Of Eight Species Of Megasoma Kirby (Coleoptera: Scarabaeidae: Dynastinae) With A Key For Identification And Notes On Biology, pp. 91-126 in The Coleopterists Bulletin 59 (1) on page 124, DOI: 10.1649/0010-065X(2005)059[0091:LDOESO]2.0.CO;2, http://zenodo.org/record/10104898