Strategus surinamensis hirtus Sternberg 1910

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 : 46-49

Strategus surinamensis hirtus Sternberg 1910

( Fig. 90-94 )

Strategus hirtus Sternberg 1910: 100

Strategus kolbeanus Prell 1934: 164 (synonym)

DESCRIPTION. Length: 18.1-40.3 mm (males); 33.2-37.8 mm (females). Width: 13.0- 19.7 mm (males); 16.6-18.5 mm (females). Color: Castaneous to piceous.

Males. Head: Frons with surface strongly punctate, with 2 strong, conical, transverse and widely separated tubercles. Eye canthus with surface punctate to rugose, apex rounded. Clypeus with narrow, weakly acuminate apex; surface rugose, slightly punctate. Antenna with 10 segments, club subequal in length to segments 2-7. Mandibles with 3 lobes; basal lobe small, apex rounded; middle lobe large, subtriangular, apex rounded; apical lobe small, triangular, apex rounded. Pronotum: Base with rugopunctate band, band reduced to basal bead at middle. Surface finely punctate, punctures small. Sides with punctures larger in size or with a rugose band at lateral margin. Fovea deep, usually with a longitudinal carina extending posteriorly from base of anterior horn. Majors ( Fig. 91 ) with anterior horn long, slender, curving forward, apex rounded. Posterior horns long, stout, laterally compressed, apex rounded. Minors not seen, presumably with a typical reduction of anterior and posterior horns. Elytra: Sutural stria strongly impressed, distinctly crenulate. Surface granulate, sparsely punctate, punctures small; occasionally with 1-3 feebly impressed striae. Sides with 2-3 short rows of moderately deep, ocellate punctures behind humerus. Pygidium: Surface finely granulate, moderately punctate, punctures small. Occasionally with a band of setigerous punctures in apical half. Lateral angles rugose. Legs: Protibia quadridentate. Apex of posterior tibia with 2-3 teeth, median tooth reduced, with rounded apex. First tarsomere of posterior tarsus elongated, quadrangular. Venter: Prosternal process densely setose, long, apex rounded. Parameres: Oval, slightly variable in degree of curvature, apex setose ( Fig. 92-93 ).

Females. As males except in the following respects: Head: Frons rugose. Mandibles similar in size, middle lobe smaller. Pronotum: Sides in basal half with lateral margin rugose to punctate. Anterior half rugose. Fovea reduced, moderately deep, surface strongly rugose to punctate. Tubercles conical, transverse. Pygidium: Surface completely rugose to punctate, densely setose, setae long. Apex with 2 small bands of setae. In lateral view, basal half convex, apical half moderately concave.

DIAGNOSIS. Strategus surinamensis hirtus can be separated from S. surinamensis surinamensis by the granulate to moderately punctate surface of the pygidium, the small punctures on pronotum and elytra, and by its geographic distribution south of the Amazon River.

DISTRIBUTION. Strategus surinamensis hirtus is distributed from the Amazon River south to Argentina, with records in Perú, Bolivia and Paraguay ( Ratcliffe 1976).

LOCALITY RECORDS. ( Fig. 94 ) 35 specimens examined (11 males, 24 females). Specimens were seen from the following collections : INPA, MZSP, MPEG.

ACRE (9): Feijó, Rio Branco . AMAZONAS (3): Benjamin Constant , BR 319 km 335, BR 319 Km 350 . MATO GROSSO (7): Chapada dos Guimarães (Fazenda Buriti), Barra dos Bugres (Reserva Ecológica

Serra das Araras), Barra do Tapirapé. PARÁ (16): Belém, Itaituba (Rio Tapajós), Santarém, Serra Norte (igarapé Fofoca).

TEMPORAL DISTRIBUTION. January (1), February (1), September (1), October (3), November (14), December (12)

BIOLOGY. Adults are attracted to lights. In Brazil, they have been taken in coconut nurseries ( Vayssiere 1965). According to Lourenção et al. (1999), S. surinamensis hirtus is a pest of 13 species of Arecaceae in several places in São Paulo state, causing great damage and death to palm trees.

In Peruvian Amazonia, adults attacks the young leaves and stem bases of the palm, Bactris gasipaes Kunth , where they form galleries of 30 cm in depth. The larvae grow in rotten trunks feeding on organic matter ( Couturier et al. 1996).

In the Brazilian Amazon, adults have been collected from secondary vegetation areas, areas of seasonal whitewater inundation forest (várzea), and ombrophilous forests at elevations ranging from sea level to 200 meters.

Figures

Figure 94. Distribution of Strategus surinamensis hirtus in Brazilian Amazonia.

Figure 90-93. Strategus surinamensis hirtus. 90) Habitus. 91) Male head and pronotum (scale line: 5 mm). 92) Parameres frontal view. 93) Parameres lateral view (scale line: 1 mm).