Description of the pupa and redescription of the third instar of Phileurus valgus (Olivier) (Coleoptera: Scarabaeidae: Dynastinae: Phileurini)

Abstract

Phileurus valgus (Olivier) (Coleoptera: Scarabaeidae: Dynastinae: Phileurini) is a common species widely distributed from the southern United States to Argentina and the West Indies. In this work the immature stages are described and illustrated based on specimens from Argentina. A key to the known third-stage larvae of New World Phileurini species is provided and updated. Notes on the life cycle and natural history are also included.

Description of the larva and pupa of Phileurus truncatus (Palisot de Beauvois, 1806) (Coleoptera: Scarabaeidae: Dynastinae: Phileurini) with a key to described third instars of New World Phileurini

“…Phileurus valgus also occurs in Florida, although this species is generally much smaller (18-29 mm adult length) than P. truncatus (29-38 mm adult length) (Ratcliffe et al 2013). Characters of the antennae serve to diagnose third instars of these species in Florida, with P. valgus having 2-4 dorsal sensory spots on the terminal antennomere (Ritcher 1966;Ibarra-Polesel et al 2017), and P. truncatus having five. (Fig.…”

“…Larvae are described for three Phileurus species: P. affinis, P. didymus, and P. valgus (Ritcher 1966;Morelli 1990;Ibarra-Polesel et al 2017). Among Phileurus species, the pupal stage is described for the South American P. affinis and the widely distributed P. valgus (Morelli 1990;Ibarra-Polesel et al 2017).…”

“…Among Phileurus species, the pupal stage is described for the South American P. affinis and the widely distributed P. valgus (Morelli 1990;Ibarra-Polesel et al 2017). Synapomorphic larval characters have not been hypothesized for Phileurus nor is there a proposed set of unambiguous characters that would serve to diagnose the genus.…”

“…Synapomorphic larval characters have not been hypothesized for Phileurus nor is there a proposed set of unambiguous characters that would serve to diagnose the genus. However, the known larvae of Phileurus share the presence of anterior frontal setae and similar sized tarsal claws on all legs (Ibarra-Polesel et al 2017). Ratcliffe & Skelley (2011) provided a synthetic key to species for the third instars of New World phileurines that serves as the standard identification tool for the group, which has been built upon by subsequent authors (Ibarra-Polesel et al 2017).…”

“…However, the known larvae of Phileurus share the presence of anterior frontal setae and similar sized tarsal claws on all legs (Ibarra-Polesel et al 2017). Ratcliffe & Skelley (2011) provided a synthetic key to species for the third instars of New World phileurines that serves as the standard identification tool for the group, which has been built upon by subsequent authors (Ibarra-Polesel et al 2017). Herein, we describe the third instar and pupa of P. truncatus (Palisot de Beauvis, 1806) based on specimens from Florida, United States of America.…”