Colacus Ohaus, 1910

Sobral, Rafael, De Morais, José W. & Grossi, Paschoal C., 2019, A new species of Colacus Ohaus, 1910 (Coleoptera: Scarabaeidae: Dynastinae) from the Mata Seca biotope of Brazil, and notes on Colacus morio Ohaus, 1910, Zootaxa 4695 (2), pp. 159-167 : 167

Key to species of Colacus Ohaus, 1910

(modified from Neita-Moreno 2015)

1. Head, pronotum, and elytra black. Pronotum with a pair of tubercles and a small, anterior fovea. Elytra rugopunctate, punctures strongly impressed.................................................................................... 2

- Head and pronotum black, elytra yellow or red. Pronotum lacking tubercles. Elytra punctate, punctures shallow.......... 3

2. Cephalic tubercle entire, sharp, conical ( Fig. 7D ). Femora ventrally black ( Fig. 6B ). External margin of mandibles slightly concave ( Fig. 7B ).............................................................. Colacus morio Ohaus, 1910

- Cephalic tubercle apically emarginate, compressed, transverse ( Fig. 2A ). Femora ventrally dark red ( Fig. 1B ). External margin of mandibles convex ( Fig. 3E )....................... Colacus rubrofemoratus Sobral, Morais , & Grossi, new species

3. Clypeal apex sharp, bristles absent. Labium, in lateral view, slightly convex. Lateral edges of paraglossae as long as labial palpomere I (see Fig. 10a in Neita-Moreno 2015: 193)................................ Colacus bicolor Ohaus, 1910

- Clypeal apex truncate, slender bristles present. Labium, in lateral view, strongly convex. Lateral edges of paraglossae shorter than labial palpomere I (see Fig. 29a in Neita-Moreno 2015: 197)................ Colacus moroni Neita-Moreno, 2015

Figures

FIGURE 1. Male of Colacus rubrofemoratus. A, Habitus in dorsal view, black arrow indicating the fourth protibial tooth; B, habitus in ventral view; C, living specimen on a log. Scale bars: 3 mm.

FIGURE 2. Head and pronotum of Colacus rubrofemoratus. A, Head in frontal view, white arrow indicating the apex of cephalic tubercle; B, head and anterior portion of pronotum in dorsal view, white arrow indicating the pronotal fovea; C, canthus in dorsal view; D, head and pronotum in lateral view, black arrow indicating pronotal tubercles. Scale bars: A–C, 1 mm; D, 3 mm.

FIGURE 3. Mouthparts of Colacus rubrofemoratus. A, Left mandible in dorsal view; B, left mandible in ventral view, white arrows indicating shallow punctures on mandible; C, left maxilla in ventral view, black arrow indicating maxillary palpifer; D, labrum in dorsal view; E, head in ventral view, black arrow indicating outer edge of right mandible, white arrow indicating punctures on mentum. Scale bars: A–D, 1 mm; E, 2 mm.

FIGURE 6. Female of Colacus morio. A, Habitus in dorsal view; B, habitus in ventral view. Scale bars: 3 mm.

FIGURE 7. Female of Colacus morio. A, Head and anterior portion of pronotum in dorsal view; B, head in ventral view, black arrow indicating outer side of right mandible, white arrows indicating apical projections of mentum; C, canthus in dorsal view; D, head and pronotum in lateral view, black arrows indicating cephalic tubercle and pronotal tubercle. Scale bars: A–C, 1 mm; D, 3 mm.