Strategus aloeus ( Linnaeus 1758 )

Alvarez, Héctor Jaime Gasca, da, Claudio Ruy Vasconcelos, Fonseca & Ratcliffe, Brett C., 2008, Synopsis of the Oryctini (Coleoptera: Scarabaeidae: Dynastinae) from the Brazilian Amazon, Insecta Mundi 2008 (61), pp. 1-62 : 43-46

Strategus aloeus ( Linnaeus 1758)

( Fig. 80-89 )

Scarabaeus aloeus Linnaeus 1758: 345

Geotrupes semiramis Fabricius 1801:12 (synonym)

Scarabaeus aesalus Laporte 1840: 112 (synonym)

Srategus julianus Burmeister 1847: 133 (synonym)

Strategus piosomus Kolbe 1906: 24 (synonym)

Strategus arizonicus Schaeffer 1915: 51 (synonym)

Strategus roosevelti Casey 1915: 241 (synonym)

Strategus frontalis Casey 1915: 243 (synonym)

Strategus tarsalis Casey 1915: 243 (synonym)

Strategus gaillardi Casey 1915: 244 (synonym)

DESCRIPTION. Length: 41.6-53.4 mm (males); 41.2-48.7 mm (females). Width: 21.1-27.6 mm (males); 19.7-24.5 mm (females). Color: Reddish brown to black.

Males. Head: Frons densely punctate to rugose, with 2 low to moderate conical tubercles. Eye canthus with apex strongly rounded, surface punctate. Clypeus with surface punctate and rugose, apex subtruncate, broadly emarginate, reflexed, usually with small notch at center ( Fig. 81 ). Antenna with 10 segments, club subequal in length to segments 2-7. Mandibles with 3 lobes; basal lobe small, rounded; middle lobe large, subtriangular, with apex broadly rounded; apical lobe small, with apex rounded to subtriangular. Pronotum: Surface of posterior half punctate, punctures small; surface of sides densely punctate, punctures small to large. Fovea deep, surface strongly punctate, divided longitudinally down middle by a broad, low, rounded carina extending posteriorly from base of anterior horn. Majors ( Fig. 82 ) with anterior horn moderate in length, stout, curving forward and upward, apex subtruncate to emarginate. Posterior horns short to moderately long, strongly laterally compressed, apex rounded and obliquely truncate with 1-3 lobes. Horns subparallel in lateral view. Minors ( Fig. 83 ) with anterior horn short, apex truncate; posterior horns reduced to short, rounded, laterally compressed projections. Base with a wide to very wide rugose band, band reduced at middle almost to basal bead. Elytra: Surface shiny. Sutural stria strongly impressed, crenulate. Surface with small punctures. Incomplete striae on lateral half of disc. Sides with small to moderate punctures, surface wrinkled to smooth behind humerus ( Fig. 84 ). Pygidium: Surface sparsely micropunctate; with band of long setae at posterior margin. Convex in lateral view. Legs: Protibia quadridentate, teeth projecting obliquely ( Fig. 85 ). Apex of posterior tibia with 3 teeth, median tooth smaller. Metatarsus with apex of first tarsomere slightly attenuated into acute angle ( Fig 86 ). Venter: Prosternal process long, apex rounded, densely setose. Parameres: Oval, stout, base broad, strongly contracted toward apex ( Fig. 87-88 ).

Females. As males except in the following respects: Head: Frons punctate, punctures small. Clypeus with apex narrow to subtruncate or rounded. Mandibles smaller, lobes with rounded apex. Pronotum: Surface of anterior half rugose, sides punctate to rugose. Fovea small, moderately deep. Conical tubercles, moderate to large, apex usually rounded. Elytra: Surface on sides occasionally with ocellate punctures. Pygidium: Surface moderately punctate, punctures small. Band of setae in posterior margin smaller, apex with 2 bands of small setae. In lateral view, basal half convex, apical half concave.

DIAGNOSIS. Strategus aloeus is the most abundant and morphologically variable species in the genus. The males could be confused with other Strategus species where external characters are used only in the identification. However, they can be separated from all other species by the shape of the parameres. The characters listed in the key will serve to separate S. aloeus from other species that occur in Brazilian Amazonia. Ratcliffe (2003) observed that S. aloeus populations in South America are usually larger in size, darker, with a deep clypeal excision and with stouter genitalia in the males, while the populations in North America and Central America are usually smaller and lighter in color.

DISTRIBUTION. Strategus aloeus is the most widely distributed species in the genus, occurring from the southern United States through Central America to central Brazil and Bolivia ( Ratcliffe 1976). This species is found commonly throughout the Brazilian Amazon.

LOCALITY RECORDS. ( Fig. 89 ) 413 specimens examined (142 males, 268 females). Specimens were seen from the following collections : INPA, CZPB, MZSP, MPEG.

ACRE (1): Rio Branco. AMAPÁ (4): Calçoene. AMAZONAS (294): Autazes, Benjamin Constant (Rio Javarí), Canutama (Nova Vista, Igarapé Gyssua), Coari, Codajas, Itacoatiara (Ponte Mamoud Amed Am 10, Fazenda Aruanã Am 10 km 215, Fazenda Saracá), Lábrea (Ramal Aperal km 9 Sitio São Raimundo), Manaus (BR 174 km 153, Coroado, INPA, Cidade Nova, Fazenda Esteio, Reserva Ducke), Manicoré, Maraã (lago Amaná, Rio Japurá), Médio Purús, Novo Airão (Rio Jaú, Ramal do Olimpo), Novo Aripuanã, Parintins, Parque Nacional do Jaú, Presidente Figueredo (UHE Balbina, Rio Urubu), São Gabriel da Cachoeira, Silves, Taracuá (Rio Uaupés), Tefé, Uarini. PARÁ (100): Ananindeua (Curuçamba), Belém, Bragança (Santa Maria), Breves (Corcovado), Capitão Poço, Gurupá, Itaituba (Santaremsinho, Rio Tapajos), Juriti, Marajó (Ponta Pedras), Melgaço (Estação Científica Ferreira Penna), Mocambo, Moju (Fazenda Latomiz), Monte Dourado, Óbidos, Oriximiná, Peixe Boi, São Francisco, São João de Pirabas (Japerica, ilha Concepção), São José, Santarém, Tucurui (Rio Tocantins). RONDÔNIA (5): Porto Velho, Surumú. RORAIMA (3): Amajari (Ilha Maracá, Rio Uraricoera).

TEMPORAL DISTRIBUTION. January (7), February (25), March (28), April (18), May (66), June (47), July (33), August (45), September (50), October (21), November (53), December (5).

BIOLOGY. In general the biology of S. aloeus is well known. Information related to the natural history of this species was presented by Ratcliffe (1976, 2003) and Ratcliffe and Cave (2006). The larvae and pupae were described by Dugès (1886) and Ritcher (1966). Hurpin and Mariau (1966), conducted experiments to observe the life cycle. Deloya (1988) found adults in nests of Atta mexicana (Smith) . Bodkin (1919) remarked on natural enemies.

In Brazil, S. aloeus has been found feeding of the roots of the “carnauba”, Copernicia cerifera Martius (Arecaceae) ( Gonçalves 1946; Bondar 1941), sugarcane Saccharum officinarum L. ( Silva et al. 1968), and the roots and lower part of the stems of coconut palms ( Costa Lima 1953; Lever 1969, Bondar 1939, 1940a,b; Carvalho 1940). The larvae of S. aloeus are important as intermediate hosts for Macracanthorhynchus hirudinaceus (Pallas) (Archiaacanthocephala: Oligacanthorhynchidae ) ( Costa Lima 1953).

Sefer (1961) classified S. aloeus as one of the species that attack coconut trees (roots and stems) in the Amazon region. In Amapá state, S. aloeus is known as “broca-do-bulbo” or bulb drill, and it is an important pest of Bactris gasipaes Kunth (“pupunheira”) ( Gazel Filho 2000). In Roraima, S. aloeus is known as “broca-da-raiz” or root drill; adults attack the young plants of the coconut palm, Copernicia cerifera , producing high mortality in large infestations ( Pereira et al. 2004).

Adults are nocturnal and are attracted to lights In Brazilian Amazonia adults have been collected from agricultural areas, semi-humid ombrophilous forests, savannah fields, and areas of seasonal whitewater inundation forest (várzea) at elevations ranging from sea level to 250 meters.

Figures

Figure 89. Distribution of Strategus aloeus in Brazilian Amazonia.

Figure 80-88. Strategus aloeus. 80) Habitus. 81) Male head (dorsal view). 82) Male major. 83) Male minor (scale line: 5 mm). 84) Elytra (lateral view). 85) Male major. 86) Male minor (scale line: 5 mm). 87) Parameres frontal view. 88) Parameres lateral view (scale line: 1 mm).