The phallus in Tettigoniidae (katydids) is a structure informative relative to the systematics of the group. Despite this, it is often not considered in descriptions of taxa. The lack of adequate descriptions of phalli is not only a gap for systematic and morphological studies, but postpones works on the evolution of copula. Here we study the exoskeletal morphology of the phallus in katydids, its components, and revised the terminology for them. We carried out dissections for morphological comparisons, and complement the observational information with published data. We stained phalli of katydids with chlorazol black, to better contrast membranous versus sclerotized components. We demonstrate that phallic components vary at specific, generic and suprageneric levels, and that internal and external components vary in number, shape, size and position. Currently there is little comparative data to support hypotheses on the evolution of this structure, but possibly the possession of a titillator is an ancestral condition. We identify additional sclerotized components, the sclerites of the ventral fold of the dorsal lobe, which can modify the shape and function of the titillator, being also important for understanding the evolution of the phallus. Potential functional relationships based on hypothetical morphological correlations between the shape of titillator and cerci are proposed, categorized in three main groups: (i) phallus devoid of titillator and cerci simple, (ii) titillator with bifurcated or paired sclerites, and cerci adapted for grasping, and (iii) titillator with single process and/or sclerite and cerci simple, sometimes with a pointed tip. Two explanations for these hypothetical morphological correlations and morphological variation are proposed: first, species with similar structures at the postabdomen would share similar copulatory behaviour, and second, more than one selective pressure would have acted over the structures of the postabdomen.

Phellinocis gen. n. is described based on three species: P. romualdoi sp. n. (type species) from Brazil, P. erwini sp. n. from Panama and P. thayerae sp. n. from Costa Rica and Panama. Diagnostic characters of the genus include the oblong, highly convex, subglabrous body, strongly declined, convex to slightly concave and often fluted elytral apices, 8or 9-segmented antennae, short and concave prosternum, laminate prosternal process, and protibia with simple outer edge and two stout teeth at apex. Phellinocis romualdoi has two features not found in any other described species of Ciidae: intraspecific variation in antennal segmentation and presence of a setal patch on the first ventrite of the female. Comparisons are made with a number of other ciid genera, and the genus is placed in the tribe Ciini. A key to species of Phellinocis is provided, together with descriptions of external morphology of adults, and morphology of male genitalia.

We report the first record of the beetle tribe Xylographellini (Ciidae) from the continental Palaearctic Region, represented by five new species discovered in Yunnan and Sichuan provinces, China: Scolytocis danae sp. nov., Syncosmetus euryale sp. nov., Sync. medusa sp. nov., Sync. perseus sp. nov. and Sync. stheno sp. nov. Illustrations and identification keys are provided for these new species, and in order to facilitate further research of Ciidae we present an open-access DNA barcode library (dx.doi.org/10.5883/DS-SYNCOSM) containing 114 records (of 44 species in 14 genera), 15 of which belong to the newly described species. A phylogenetic analysis based on the barcode fragment of the cytochrome oxidase I gene did not recover much tree structure within Ciidae, however both Xylographus Mellié and Syncosmetus Sharp were recovered as clades, with a single Scolytocis Blair being the sister to the latter.