Cyclocephala dichroa Dechambre, 1992

Joly, Luis J., 2009, Review of the species in the Cyclocephala bicolor Laporte species group (Coleoptera: Scarabaeidae: Dynastinae), Zootaxa 2048, pp. 47-64: 60-62

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Cyclocephala dichroa Dechambre, 1992


Cyclocephala dichroa Dechambre, 1992 

( Figs. 2View FIGURE 2, 11–14, 22View FIGURES 3 – 23, 29–30View FIGURE 24 – 33, 39View FIGURE 34 – 48, 46–47, 53View FIGURES 49 – 57 – 54, 60View FIGURE 58 – 77, 65–66, 71 – 72)

Bibliography. Cyclocephala dichroa Dechambre 1992: 67  (description of male; compared with C. bicolor  , C. bicolorata  ), Fig. 31View FIGURE 24 – 33 (genitalia), French Guiana. Holotype male, MNHN. Type locality: French Guiana: Route du Kaw, PK 12.

Description. Short, oval, moderately shiny. Brownish red, posterior part of clypeus, frons brownish red or black, vertex black, elytra testaceous, sometimes with base and a reddish brown posteriorly narrowed sutural band; dorsal surface and pygidium glabrous, ventral pubescence sparse. Length: 10.0–13.0 mm.

MALE: Clypeus ( Fig. 11View FIGURES 3 – 23) about 2.4 times as wide across base as long; sides straight, strongly convergent to truncate and not reflexed apex, shallowly sulcate longitudinally along middle and shallowly depressed laterally before apex, in lateral view slightly convex on apical half; surface finely alutaceous, with fine, shallow and widely annulate punctures, annulation wide, not well defined posteriorly, sometimes confluent, in which case appearing as irregular and fine, more or less transverse striae. Frontoclypeal suture ( Fig. 11View FIGURES 3 – 23) thin, not well defined, feebly bisinuate, but not pointed posteriorly at middle. Frons: width about 2.4 times transverse diameter of eye, finely alutaceous; punctures stronger and more discrete than those on clypeus.

Mandibles with external border sinuate, apex projecting externally. Maxillae ( Fig. 14View FIGURES 3 – 23) with galea moderately robust, with two apical, one median and three basal teeth, the basal teeth very small and arising from a common base; stipes projected anteriorly on inner side and with a brush of fine yellowish brown setae on apex of projection; maxillary palpi ( Fig. 22View FIGURES 3 – 23) moderately robust, second palpomere widened towards apex, longer than third, fourth fusiform, more than 3.0 times as long as preceding. Labium ( Fig. 13View FIGURES 3 – 23) with sides slightly convex on basal two-thirds, not constricted at middle of apical third; apex uniformly convex on ventral side, more arcuately produced, with small emargination at middle on oral side, fimbriate with long, fine, yellowish brown setae; surface almost flat, impunctate on disc, with one longitudinal series of long bristles on each side converging towards base.

Antennae with 10 antennomeres, club almost 2.0 times the length of antennomeres 2–7 together.

Pronotum 1.5 times as wide as long, widest near base, sides more strongly convergent to apex on anterior half; anterior border widely and arcuately projected at middle; basal angles widely rounded; basal border without marginal bead, almost uniformly arcuate, slightly more projected in central third; surface finely alutaceous (40 X); punctures annulate, moderately fine and dense, the distance between most punctures on disc as long as or longer than diameter of punctures, punctures gradually larger toward sides, the diameter of a puncture about 2.0 times the diameter of those on center of disc, more dense on basal angles where the distance between most punctures is as long as or shorter than diameter of a puncture; all surface also covered with numerous minute punctures (50 X or more). Scutellum triangular, sides feebly arcuate, apex briefly rounded; punctures similar to those on pronotal disc.

Elytra 1.1 times as long as wide, arcuately widened from first quarter to middle, then rounded to apex, sutural angle well defined, but rounded; humeral and apical umbones weak; a feeble, short, elongate tumescence behind humeral umbones on external border; surface smooth, with large, shallow, annulate punctures, much smaller on sides and apex, double rows not evident, also with numerous micropunctures (50 X or more) scattered all over the surface; sutural interstria flat, a little elevated on apical half. Epipleura narrow, more so apically.

Pygidium almost 2.0 times as wide as long; in posterior view the inferior borders almost straight, converging to feebly convex-truncate apex in an angle distinctly greater than 90 °; in lateral view ( Fig. 65View FIGURE 58 – 77) convex, more strongly on apical half; surface smooth, shiny, with large annulate punctures, more dense on lateral angles; on apex more shining, the punctures somewhat smaller and less dense, the distances between most punctures 1.0–2.0 times their own diameter.

Protibiae ( Fig. 29View FIGURE 24 – 33) tridentate, small basal tooth separated from the intermediate tooth by a distance 2.0 times as long as that between intermediate and anterior teeth; intermediate and anterior teeth well developed, basal tooth acute and anteriorly projected; apical spur almost straight, surpassing apex of first tarsomere. Protarsi ( Fig. 39View FIGURE 34 – 48) enlarged; tarsomere 5 shorter than 1–4 together, without ventro-internal carina, ventral side with inconspicuous longitudinal striae on inner side of apex; tarsomere 4 longitudinally striated on about apical half, tarsomere 3 usually without apical striae, sometimes (2 out of 6 males) with 1–2 striae on inner side of apex; largest claw ( Figs. 46–47View FIGURE 34 – 48) wide, flattened, moderately widely cleft at apex, the external border of small branch continuous with internal curvature of the claw. Metafemur ( Fig. 53View FIGURES 49 – 57) 2.0 times as long as its maximum width. Metatibiae ( Fig. 53View FIGURES 49 – 57) robust, widened at apex, bristles on diagonal carina and apex very strong. Metatarsi subequal in length to tibiae, with first tarsomere widened towards apex, with apical bristles similar to those of apex of tibiae.

Prosternal projection high, apex alutaceous, anterior part transversely oval, externally pointed; posterior part with posterior border fimbriate with long bristles.

Pronotal hypomera alutaceous, with sparse, erect setae. Mesopleura, metapleura, and sides of metasternum alutaceous, with large, dense, confluent, annulate punctures; disc of metasternum smooth, with small, scattered punctures; metacoxae with small, moderately dense punctures, more dense and confluent on posterior and external borders. Ventrites with moderately dense annulate punctures, some open posteriorly; second ventrite with strong, triangular carina along middle, from basal quarter to apex.

Aedeagus: Figs. 71–72View FIGURE 58 – 77.

FEMALE: differs from the male in the following characters: punctation generally stronger, that of pygidium of the same size; protarsi slender; protibiae Fig. 30View FIGURE 24 – 33; metafemora ( Fig. 54View FIGURES 49 – 57) somewhat more robust; metatibiae Fig. 54View FIGURES 49 – 57; pygidium ( Fig. 66View FIGURE 58 – 77) flattened in lateral view; epipleura ( Fig. 60View FIGURE 58 – 77) strongly narrowed before anterior border of metacoxae, then widened up to level of middle of second ventrite.

Distribution: Venezuela, French Guiana, Brazil, and Peru. Venezuela, Brazil, and Peru are new country records.

Specimens studied: VENEZUELA: Amazonas: Culebra, P. N. Duida-Marahuaca, 3 º 44 ’ N, 65 º 46 ’ W, 24-26 -I- 1992, Exped. Terramar, J. Clavijo-A. Chacón, 1 F ( MIZA). Pto. Ayacucho, 22 -IV- 1967, P. J. Salinas, 1 M ( MIZA); 4-15 -XII- 1982, G. Romero, 4 F ( MIZA). Rio Baría, 0º 55 ’ N, 66 º 10 ’ W, 140 m, L. J. Joly-A. Chacón, 1 F ( MIZA). Barinas: Reserva Forestal de Ticoporo, 230 m, 10 -IV- 1968, en la luz, F. Fernández Y.- L. J. Joly, 1 F ( MIZA). Bolívar: El Barroso, Río Matú, 7 -I- 1972, J. Salcedo, 1 F ( MIZA). Los Pijiguaos, 600 m, 3-13 -VI- 1992, Exped. MIZA, 1 M ( MIZA). Río Guaniamo, 6 º 45 ’ N, 66 º 01’ W, 8-12 -V- 1979, 1 M ( MIZA). Portuguesa: Biscucuy, 13 -IV- 1981, 1 M ( MIZA). Táchira: Nula, 9 -III- 1967, L. J. Joly-V. Obregón, 2 M, 1 F ( MHNLS). BRAZIL: Pará: Cachimbo, 400 m, 14 / 21 -IX- 1955, L. Travassos & S. Oliveira, 5 M, 1 F ( HAHC). PERU: Huánuco: Tingo María, 17 -V- 1947, 2.200 ft, J. C. Pallister Coll. Donor Frank Johnson, 1 F ( AMNH).

Other localities: FRENCH GUIANA: Route de Kau; Saül; St. Laurent ( Dechambre 1992).


Museum National d'Histoire Naturelle


Museo del Instituto de Zoologia Agricola Francisco Fernandez Yepez


Coleccion de Mastozoologia, Museo de Historia Natural de La Salle


American Museum of Natural History