Rhytiphora collaris

REVISION OF THE RHYTIPHORA COLLARIS GROUP

The species R. collaris Donovan, 1805 belongs to a distinct group of five species with broadly separated antennae, small eyes and a curved white lateral stripe on the humeri. The group consists of: R. garnetensis sp. nov., R. amicula White, 1859, R. collaris, R. delicatula McKeown, 1948 and R. piperitia Hope, 1841. Preliminary analysis of mitochondrial data for all of these species (except R. delicatula) confirms they are closely related but distinct lineages (Ashman et al. 2022a). Here, we redescribe the species of the collaris group, as well as the morphologically similar (but genetically distant) R. argentata.

Key to species

1. Clypeus short (in line with mandibular articulation), with membranous anteclypeus visible beneath (Fig. 7D); elytra with lateral white stripe usually extending from base to apex (Fig. 8E); metanepisternum usually white...... R. collaris Donovan, 1805

– Clypeus extended beyond mandibular articulation, sometimes covering membranous anteclypeus (Fig. 7E); elytra lateral white stripe never extending beyond basal third of elytron (Fig. 8A–C); metanepisternum not white.........................2.

2. Prothorax with distinct transverse grooves on pronotal disc and anterior tubercule at lateral margin (Fig. 7B).............3.

– Prothorax without distinct transverse grooves on pronotal disc or anterior tubercule at lateral margin (Fig. 6C)...........4.

3. Eyes deeply emarginate; antennal tubercules ~3.2 widths apart; antennomeres 3–7 with banded setae (Fig. 8F); elytra usually heavily mottled with dorsal dark patches (Fig. 7B; may be faded); male genitalia with parameres apically tapered, penis pointed (Fig. 9E).......................................................................... R. piperitia Hope, 1841

– Eyes fully divided; antennal tubercules ~3.9 widths apart; antennomeres 3–7 with plain setae (Fig. 8C); elytra lightly mottled without dorsal dark patches (Fig. 6F); male genitalia with parameres apically blunt, penis rounded (Fig. 9B).............................................................................................. R. amicula White, 1859

4. Eyes fully divided, lower lobes ~3.4 widths apart; clypeus flat; antennal tubercules ~3.2 widths apart; elytral base tuberculate, heavily mottled with ochre setae (Fig. 6A); metaventrite with ochre patches above metacoxae (Fig. 6B); male genitalia with parameres apically tapered (Fig. 9A).................................................... R. garnetensis sp. nov.

– Eyes deeply emarginate, lower lobes ~4.3 widths apart; clypeus arcuate; antennal tubercules ~3.8 widths apart; elytral base granulate, lightly mottled with ochre setae (Fig. 6E); metaventrite without ochre patches; male genitalia with parameres apically blunt (Fig. 9D)............................................................... R. delicatula McKeown, 1948