Platyphysus obtusus ( Chapuis, 1865 )

Kirkendall, Lawrence R., 2017, New Synonymies in Neotropical Platypodinae (Coleoptera: Curculionidae), The Coleopterists Bulletin 71 (1), pp. 95-98 : 95-96

Platyphysus obtusus ( Chapuis, 1865)

Platypus obtusus Chapuis 1865: 251 .

Platyphysus obtusus (Chapuis) : Wood 1993: 275.

Platypus frontalis Blandford 1896: 113 . New synonymy.

Platyscapulus frontalis (Blandford) : Wood 1993: 274.

Costaroplatus frontalis (Blandford) : Alonso- Zarazaga and Lyal 2009: 11.

Platypus turgifrons Schedl 1935: 358 . New synonymy.

Platyscapus turgifrons (Schedl) : Wood 1993: 274.

Costaroplatus turgifrons (Schedl) : Alonso- Zarazaga and Lyal 2009: 11.

Platypus particeps Schedl 1976: 91 . New synonymy.

The type species of Platyphysus Wood, 1993 is Platyphysus obtusus ( Chapuis, 1865) . I have specimens of P. obtusus that I compared with the two male Chapuis syntypes in IRSNB. Careful examination of dozens of specimens of this species and of C. frontalis (holotype examined, NHMUK) has convinced me that the latter is the female of the former. All known specimens of P. obtusus , in all collections, are male; all known specimens of C. frontalis , in all collections, are female. While I have not collected males and females from the same galleries, during the course of my biodiversity research in Costa Rica I have seen many samples with both of these forms present and no other candidates for the opposite sex for either species. The two are similar in size, shape, and color and exhibit the same form of sexual dimorphism of the frons and the elytra as do other species of Platyphysus and Costaroplatus Nunberg, 1963 . The antennal scape is identical for the two forms, and the two share details of the metepisternum – metasternum impression (shape and the number and pattern of bordering small teeth). Both are collected from low elevation tropical forests of Mexico, Central America, and South America, at least as far south as Peru and Brazil. Further support for the association of P. obtusus males with C. frontalis females comes from the similar but smaller congener Platyphysus pouteriae (Wood) , known only from the type series from Venezuela, which exhibits identical sexual dimorphism. The species C. frontalis , then, must be transferred from Costaroplatus to Platyphysus , where it becomes a junior synonym of P. obtusus .

While researching these two genera, I discovered two further synonymies, P. particeps and C. turgifrons (types of both in NHMW). Platypus particeps from Brazil was overlooked in Wood ’ s (1993) treatment of Platypodinae genera, so has not been formally assigned to a Neotropical genus. The P. particeps series is particularly informative. This series includes the holotype male, allotype female, three male paratypes, and one female paratype. Male P. particeps are indistinguishable from P. obtusus , and female P. particeps are identical with C. turgifrons and C. frontalis . Schedl (1976) described P. particeps towards the end of his life, which may explain why he overlooked the similarities with previously described species. The specimens of these species are in quite close proximity in Schedl ’ s collection: the P. particeps series is directly under two male specimens of P. obtusus and is in the same drawer (six rows over) as a series of seven female C. frontalis , the series of which, in turn, is three species above the female holotype of C. turgifrons .

Females of Platyphysus and Costaroplatus share a number of derived character traits. Males of Platyphysus and Costaroplatus are also very similar, differing primarily in details of the fifth ventrite, which is swollen in Platyphysus but has a pair of conical projections in Costaroplatus ( Wood 1993) . The two genera are doubtfully distinct, and this a matter of current investigation.