Phileurus didymus (Linnaeus, 1758)

Ratcliffe, Brett C., 2011, A Review of the Species ofPhileurusLatreille (Coleoptera: Scarabaeidae: Dynastinae: Phileurini) with Quadridentate Protibiae and Description of a New Species from Panama, The Coleopterists Bulletin 65 (2), pp. 125-129 : 126

Phileurus didymus (L., 1758)

( Fig. 1 )

Scarabaeus didymus Linnaeus 1758: 347 (original combination).

Phileurus affinis Reiche 1859: 12 (synonym).

1′. Metatibia at apex with 2 large teeth.............2

2. Elytral disc with alternate intervals convex, distinctly higher than even intervals. Parameres as in Fig. 3............................. P . valgus (Olivier)

2′. Elytral disc with all intervals subequal in height..........................................................................3

3. Pronotum densely punctate, punctures confluent or nearly so; elytral intervals with small, extremely dense punctures, punctures confluent or nearly so. Parameres as in Fig. 2 .................................. P. toulgoeti Dechambre

3′. Pronotum moderately to incompletely, densely punctate but punctures not all contiguous; elytral intervals with small, sparse punctures, punctures not confluent or nearly so.............4

4. Pronotal disc either side of median furrow with punctures sparse to moderate in density. Occipital fovea in male rugose inside. Parameres with medially projecting lobes short ( Fig. 4 ) ................ P. voirinae Endrödi

Phileurus didymus is a relatively abundant species that is broadly distributed from Mexico to Paraguay (Endrödi 1978, 1985a) and the West Indies ( Chalumeau 1983). This species and Phileurus truncatus (Palisot de Beauvois) are the largest species in the genus. An occasional specimen of P. didymus will have a nearly obsolete basal tooth on the protibia, but even under these circumstances the single, stout tooth on the apex of the metatibia and the form of the parameres ( Fig. 1 ) will distinguish this species.

Ritcher (1966) described the larval stage. Both larvae and adults have been found in rotting wood ( Ritcher 1966; personal observation), and adults are frequently encountered at lights, especially in lowland areas. Little else is known of their life history. They have been collected from many types of forest including tropical dry broadleaf forests, montane broadleaf and pine-oak forests, and lowland broadleaf forests. They occur from sea level to 1,800 m in elevation. Adults have been captured during all months of the year (Ratcliffe 2003; Ratcliffe and Cave 2006).

Figures

Figs. 1–7. Parameres of 1) Phileurus didymus; 2) Phileurus toulgoeti; 3) Phileurus valgus; 4) Phileurus voirinae; 5–7) Phileurus zonianis.