Golofa minutus Sternberg, 1910

Ratcliffe, Brett C., Cave, Ronald D. & Mondaca, José, 2021, The Dynastine Scarab Beetles (Coleoptera: Scarabaeidae: Dynastinae) of Chile, The Coleopterists Bulletin 75 (2), pp. 279-309 : 298

Golofa minutus Sternberg, 1910 ( Figs. 38–44 )

Golofa minutus Sternberg 1910: 37 (original combination).

Redescription [based on original description and images in Lachaume (1985)]. Length 22.0– 30.0 mm; width 12.0– 15.3 mm. Color dark yellowish brown or reddish brown except for black head, black or piceous markings on pronotum, scutellum, elytral margins, tibiae, tarsi, pygidium, and venter ( Fig. 44 ). Head: Frons with moderately large, dense punctures. Clypeus with erect, sharply acuminate tubercle; apex strongly narrowed, emarginate. Interocular width equals 2.7 transverse eye diameters. Antenna with 10 antennomeres, club subequal in length to antennomeres 2–7. Pronotum: Surface with punctures moderately large (largest on disc), moderately dense. Base with marginal bead. Elytra: Surface punctate-striate, punctures moderately large, moderately dense. Sutural stria a series of closely spaced punctures. Pygidium: Surface finely rugulopunctate. Propygidium with long, dense setae projecting over base of pygidium. Legs: Protibia tridentate (with additional small swelling suggestive of a 4th tooth), basal tooth removed from other teeth. Parameres: As in Fig. 40 .

Distribution. Golofa minutus occurs in the bor- der area of Chile and Peru.

Locality Records ( Fig. 43 ). 35 specimens from BCRC, FSCA, JMEC, MAHC, MNNC, SLTC , and UTAC.

REGIÓN DE ARICA Y PARINACOTA (33): ARICA (31): Arica, Azapa Grande, Camarones , San Miguel de Azapa , Valle de Azapa. PARINACOTA (2): Putre, Parinacota . REGIÓN DE TARAPACÁ (2): TAMARUGAL (2): No data .

Temporal Distribution. January (3), March (1), August (1), September (2), October (5), November (11), December (12).

Diagnosis. The pronotum of G. minutus has dark areas or is nearly completely dark reddish brown, while the lateral and sutural elytral margins are black ( Figs. 38–39, 41–42 , 44 ); the sutural stria consists of closely spaced punctures; and the propygidium has long, dense setae. Conversely, the pronotum and elytra of G. inermis are monochromatic yellowish brown or reddish brown (except for the black elytral suture); the elytral suture is a completely impressed line; and the propygidium lacks long, dense setae. The parameres of the two species differ, with those of G. minutus more slender (compare Figs. 40 and 36 ).

Nomenclature. In spite of Endrödi (1985), Lachaume (1985), and most catalogs that list two species in Chile, there has long been doubt about the validity of G. minutus since it shares most characters with G. inermis . The line drawing of the parameres of both species in Endrödi (1985) appear different, while the line drawings of the parameres in Lachaume (1985) are nearly identical. Endrödi (1985) characterized G. inermis as being “normally” setose on the venter and propygidium, while G. minutus is densely setose on the venter and propygidium. Our study of the types of G. inermis and specimens of G. minutus confirm that there are two distinct species of Golofa in Chile.

Natural History. Adults are attracted to lights in rural sectors near the city of Arica (border with Peru) and are also common in a sector called Valle de Azapa that has a path with abundant public light- ing. Larvae feed on decomposing organic matter and are easy to breed in a substrate prepared with peat, milled wood, and rice husks (JME, personal observation).

GENERAL REMARKS

Chile has the lowest dynastine species richness among all South American countries. Ecology and geography are the two factors that explain why only eight species inhabitat the country. The tropical and subtropical northern zones are dominated by the xeric, poorly vegetated rain shadows created by the high Andes. Soil that is dry and low in organic content is not favorable habitat for dynastine larvae. The few forested habitats and the species that live in them are restricted in this harsh habitat to widely separated riverine areas. The southern temperate zone of Chile is cold and windy most of the year. This type of weather is not propitious for dynastines as a whole as shown by the low species richness at the same northern latitudes of the USA and Canada (Ratcliffe and Cave 2017).

ERRONEOUS RECORDS

The following species have been cited in the literature or found in a collection and labeled as being from Chile. We believe these records are erroneous because singletons residing in collections are either likely mislabeled, misidentified, or represent inadvertent transport to the study area (by ship, trucks, buses, cars, or import of merchandise into Chile) and have no established population. Nevertheless, catalogers (e.g., Blackwelder 1944; Krajcik 2005), simply repeating the literature without vetting, continued to list them from Chile, thus promulgating incorrect distributions. The only exception is 11 km W of Lumaco in Malleco Province in central Chile. The specimen might have been transported to Chile from Peru via international trade. Ancognatha castanea does not occur in Chile.

Figures

Figs. 38–42. Golofa minutus. 38) Male, dorsal view; 39) Male, lateral view; 40) Parameres; 41) Female, dorsal view; 42) Female, lateral view. Photographs by Marcelo Guerrero (Santiago, Chile).

Fig. 43. Golofa minutus, distribution. Red dot indi- cates provincial record with no specific locality data.

Fig. 44. Golofa minutus at Valle de Azapa, Arica, Región Arica y Parinacota, Chile. Photograph by Marcelo Guerrero (Santiago, Chile).

Figs. 34–37. Golofa inermis. 34) Lectotype, MNHN-EC-2378; 35) Lectotype labels; 36) Parameres; 37) Distribution. Images in Figs. 34–35 courtesy of Antoine Mantilleri (Muséum National d’Histoire Naturelle, Paris, France).