Platyceroides Benesh, 1946

Paulsen, M. J., 2017, Correction of existing generic and species concepts in Platyceroidini (Coleoptera: Lucanidae: Lucaninae) and the description of four new species of Platyceroides Benesh, Zootaxa 4269 (3), pp. 346-378 : 350-351

Subgenus Platyceroides Benesh, 1946

Subgeneric diagnosis. Differing from other subgenera in the following characters. Head: Anterior margin subtruncate (Fig. 20). Genae not produced laterally past eyes (greatest width of head is across eyes). Wings: Males with functional wings. Abdomen: Male genitalia with internal sac (flagellum) elongate, much longer than parameres, entirely sclerotized, gradually ( P. agassii group only) or abruptly expanded at apex ( Fig. 2 ). Parameres complexly folded and emarginate ( Fig. 1 C).

Species groups. In the nominal subgenus the flagellum of the male genitalia is a snake-like, elongate, entirely sclerotized structure ending in a gradually or abruptly expanded apex ( Fig. 1 C). To facilitate correct identification, four species groups are used so that similar species can be compared directly. These groups can be defined within the nominal subgenus based on the form of the apex of the flagellum and elytral surface and punctation. In the P. agassii group (two species) the apex is much broader (gradually widening) and subcylindrical ( Fig. 2 A), with the elytral surface usually glossy.

In the P. pampinatus group (two species) the abruptly expanded apex ends with a leaf-like sclerite ( Fig. 2 B) visible in distal view and the elytral surface is shagreened ( Fig. 5 ). Females of this group have moderate to large antennae for the subgenus. The two species in the P. pampinatus group have been most confused with P. agassii by previous authors and therefore had both remained undescribed, even though this group is represented by the most specimens in collections. The species are widespread along the coast from southern Oregon to central California, also extending inland in the northern half of that range.

The remaining species in the nominal subgenus have a more similar, abruptly capitate apex of the flagellum ( Fig. 2 C–D) and form the last two species groups, depending on whether the elytra are distinctly glossy/polished and striate ( P. californicus group, four species) or dull or shagreened and more irregularly punctate ( P. opacus group, four species). Within these two groups differences in the capitate apex of the flagellum remains diagnostic to species.

Figures

FIGURE 1. Illustration of the overall morphology in male genitalia in lateral view for the subgenera of Platyceroides Benesh, with parameres indicated in black. 1 A, Platyceropsis Benesh, flagellum reduced to a short hook, paramera simple; 1 B, Praocerus, flagellum basally membranous (white) with distal sclerotized process, parameres emarginate; 1 C, Platyceroides nominal subgenus, long sclerotized flagellum, parameres complex and folded.

FIGURE 2. Form of the flagellum of the male genitalia in species groups of the nominal subgenus. 2 A, Platyceroides agassii species group, cylindrical and gradually widening to apex (basal piece and parameres shown for context); 2 B, Platyceroides pampinatus species group, flagellum abruptly widening, apex with sclerotized tip; 2 C, Platyceroides californicus species group; 2 D, Platyceroides opacus species group, apices abruptly widened.

FIGURE 5. Scanning electron microscope image of elytral surface of Platyceroides pampinatus new species, showing shagreened microsculpture between punctures.