Ripidius primordialis, STEIN, 1877

Batelka, Jan, Perkovsky, Evgeny E. & Prokop, Jakub, 2020, Diversity of Eocene Ripiphoridae with descriptions of the first species of Pelecotominae and larva of Ripidiinae (Coleoptera), Zoological Journal of the Linnean Society 188, pp. 412-433 : 424

RIPIDIUS CF. PRIMORDIALIS STEIN, 1877

Specimen: Male of ‘ Ripiphorus ’ sensu Berendt (1845) and Kaupp et al. (2001), preserved in a piece of Baltic amber, ex. collection Edmund Berendt (MNHUB, Item no.: MB.I.6564). Kaupp et al. (2001, fide Hieke & Pietrzeniuk, 1984) mentions the specimen was ‘broken into pieces’. The specimen was subsequently glued together by the curator Dr Christian Neumann (Museum für Naturkunde, Leibniz- Institut für Evolutions und Biodiversitätsforschung an der Humboldt-Universität, Berlin) to allow its examination.

Diagnosis (based on photomicrographs Fig. 8A–D): Head globular; compound eyes large, expanded ventrally and dorsally, coarsely faceted; postocular ommatidia indiscernible; labial palpi and mandibles absent; maxillary palpi reduced, placed ventrally adjacent to each other, each palpus consists of one long, terminal palpomere and several times shorter basal palpomere; antennae 11-segmented, uniflabellate; antennomeres I–III simple, without projections; antennomeres IV–XI each with long, compressed ramus; elytra much shorter than abdomen, with rounded apices, widely separated from each other, longer than wide; metathorax with obvious triangular metascutellum; basal shaft of metatrochanters projects greatly beyond metathorax; metatibial spurs and spiniform setae on apex of metatibia absent.

Identification: Examined photomicrographs show that Berendt’s ‘ Ripiphorus ’ do not belong to any genus of the subfamily Ripiphorinae [see remarks in Kaupp et al. (2001)], but is a male of the subfamily Ripidiinae , tribe Ripidiini . Its set of characters [e.g. two-segmented maxillary palpi and 11-segmented antennae (formula 3 + 8)] fits the definition of the genus Ripidius Thunberg, 1806 , with the exception of the putative absence of postocular ommatidia (the presence or number of which is no longer considered a generic character in some studies, e.g. Viana, 1958; Batelka et al., 2011). Unlike in the Berendt specimen, in Ripiphorinae the eyes are always widely separated, elliptical, and finely faceted, mouthparts are fully developed, antennomeres IV–X in males are biflabellate (each respective antennomere bears two long, thread-like or flattened rami), elytra are either scale-like or triangular, and always touch each other at their base, and metatibial spurs and apical spiniform setae are present. Irrespective of the details of all the characters mentioned above, the two subfamilies are dissimilar in habitus, so their misidentification is impossible once the researcher is familiar with the systematics of this family. Males of Ripidius are abundant in Baltic amber ( Kaupp et al., 2001; Batelka et al., 2011; Batelka, unpublished data), but their specific identifications have never been investigated since the description of R. primordialis , and are in need of revision.