Cyclocephala compacta Ratcliffe, 2008

Ratcliffe, Brett C., 1821, More New Species ofCyclocephalaDejean, 1821 from South America (Scarabaeidae: Dynastinae: Cyclocephalini), The Coleopterists Bulletin 62 (2), pp. 221-241 : 221-241

Cyclocephala compacta Ratcliffe , new species

( Figs. 17–20 )

Type Material. Holotype male, labeled ‘‘ BRASIL: Rondonia, 62 km S. Ariquemes, Fazenda Rancho Grande , 10 ° 32 9 S, 62 ° 49 9, X-5-15-1993, C. & K. Messenger. ’’ Allotype and 3 paratypes with same data. Five additional paratypes labeled ‘‘ BRASIL: Rondonia, 62 km S Ariquemes, 165 m, Fazenda Rancho Grande , 10 ° 32 9 S, 62 ° 49 9, 19–31 Sept. 1994, coll. A. Reifschneider. ’’

Holotype, allotype, and two paratypes deposited at the University of Nebraska State Museum, Lincoln, NE. Two paratypes deposited in the Alex Reifschneider Collection and four paratypes deposited in the B. C. Ratcliffe Collection (both Lincoln, NE) .

Holotype. Male. Length 12.2 mm; width across humeri 7.2 mm. Color testaceous except for black frons; dark testaceous clypeus with black bead on apex; 6 small, black spots on pronotum (4 in transverse row and 1 each behind median spots in transverse row); elytra with curved, black macula behind humerus, short black line near middle, and small black spot mesad of black line; pygidium black either side of middle; protibial teeth black; femora and tarsi dark testaceous; meso- and metathorax and abdominal sternites piceous. Head: Frons with dense, moderately large punctures. Frontoclypeal suture biarcuate, distinct. Clypeus with surface vaguely, transversely rugopunctate; apex semicircular with thin, marginal bead. Interocular width equals 3.0 transverse eye diameters. 230 (caudal and lateral views); 20) pronotum showing variation in spots.

Antenna 10-segmented, club slightly longer than segments 2–7. Pronotum: Surface weakly shagreened, moderately punctate at center; punctures moderately large, becoming denser on sides. Base with complete marginal bead. Posterior angles broadly rounded. Elytra: Surface weakly shagreened, punctate; punctures large, dense, double rows of punctate striae indistinct. Apical angles with sparse, minute setae. Pygidium: Surface opaque, vaguely shagreened, vaguely punctate; punctures dense, moderately large, shallow, setigerous; setae short, tawny. In lateral view, surface regularly convex. Legs: Protibia tridentate, basal tooth small and strongly removed from apical teeth; median tooth with anterior edge perpendicular to shaft of tibia ( Fig. 17 ). Protarsus strongly enlarged; tarsomeres 2–4 each slightly larger than preceding; 4th with subtriangular, ventral lobe, 5th subequal in length to tarsomeres 1–4; median claw enlarged, strongly bent, apex narrowly split into large and small rami. Metatarsus a little longer than metatibia. Venter: Prosternal process long, columnar, apex transversely oval and flat with a raised, transverse ‘‘button’’ on anterior half. Parameres: Figs. 18–19 .

Allotype. Female. Length 11.6 mm; width across humeri 6.8 mm. As holotype except in the following respects: Color and pattern similar except pronotum with only 1 small, black spot behind each anterior angle, elytra with transverse band on disc reduced a spot, and swelling of elytral margin darkened. Elytra: Surface with minute setae absent from near apex. Epipleuron (in ventral view) gradually tapering towards apex, abruptly narrowed at level of sternite 1. Lateral margin slightly swollen at level of sternites 1–2. Pygidium: Surface shiny, punctate; punctures minute and moderately large mixed, moderate in density on disc, dense on sides, setigerous; setae sparse on sides, minute, tawny, absent elsewhere. In lateral view, surface weakly convex. Legs: Protarsus simple, not enlarged. Metatarsus subequal in length to metatibia.

Variation. Males (4 paratypes). Length 12.3–14.0 mm; width across humeri 7.1–7.4 mm. The paratypes do not differ significantly from the holotype except for variation in the number of spots on the pronotum: 1 as holotype, 1 lacking posterior 2 spots, and 2 with 6 spots in anterior row ( Fig. 20a–c ). All of the male paratypes have a black, subtriangular mark on the base of the clypeus.

Females (4 paratypes). Length 11.0–13.0 mm; width across humeri 6.6– 7.4 mm. The female paratypes do not differ significantly from the allotype except for variation in the number of spots on the pronotum and elytra: 2 specimens with 4 spots in transverse row on pronotum and 2 specimens with 4 spots in transverse row on pronotum followed by 2 additional spots in second row. Two specimens with 2 discal spots instead of 1.

Etymology. The name is derived from the Latin compactus, meaning thick or compact, in reference to the relatively compact and stout body form of this species.

Distribution. Cyclocephala compacta is known from the Schmidt farm south of Ariquemes, Rondônia, Brazil. This area has been largely cut over for agriculture except for the Schmidt farm, which is now a relict island of biodiversity. Emmel and Austin (1990) reported this area had the highest species diversity of butterflies in the world, and a number of new species of scarabs ( Ratcliffe 1992) have also been described from this single, rich locale.

Diagnosis. Males of C. compacta with six spots on the pronotum will key to couplet 130 in Endrödi (1985), which is C. quatuordecempunctata Mannerheim. Cyclocephala quatuordecempunctata , however, has elytral setae, no pygidial spots, and parameres different from those of C. compacta . Specimens with only two or four spots on the pronotum do not go through the key. This kind of variation illustrates the difficulty in constructing a key that relies on the numbers of spots on the pronotum or elytra; specimens will not properly key if only one character state is mentioned. On the other hand, Mannerheim probably did not have a series that showed this variation nor possibly did Endrödi when he created the key. The parameres of C. compacta are somewhat similar to those of C. howdenannae Endrödi , but that species has an emarginate clypeus, no basal bead on the pronotum, and is larger (18 mm).

Figures

Figs. 17–20. Cyclocephala compacta: 17) dorsal view of holotype; 18–19) parameres