A review of the trunk‐boring cycad weevils in Australia, with description of a second species ofDemyrsusPascoe, 1872 (Coleoptera: Curculionidae)

Abstract

The Australian trunk‐boring cycad weevils of the genera Demyrsus Pascoe, 1872 and Siraton Hustache, 1934 (Molytinae) are sometimes considered as cycad pests when they infest planted cycads and can be transported to other countries. In the present study, the taxonomy of Demyrsus and Siraton is reviewed, and four species are recognised: D. meleoides Pascoe, 1872, D. digmon sp. nov., S. internatus (Pascoe, 1870) and S. roei (Boheman, 1843). The discovery of a second species of Demyrsus illustrates a larger diversity of cycad‐associated weevils in Australia than currently known and identifies a further species with the potential to damage and kill cultivated cycads. The species descriptions and diagnoses are supplemented with illustrations of the habitus and salient structures, a distribution map and an identification key to all species of trunk‐boring cycad weevils in Australia. Their potential hosts are identified from a spatial analysis of their distributions and the distributions of the cycad taxa occurring in this range.

A review of Paratranes Zimmerman, 1994, Xanthorrhoea-associated weevils of the Tranes group (Coleoptera, Curculionidae, Molytinae), with description of a new species

“…The relationships of Paratranes to the other genera of the Tranes group also remain uncertain for the moment. It agrees with Tranes, Miltotranes Zimmerman, 1994 andHoweotranes Zimmerman, 1994 in lacking sclerolepidia along its metanepisternal sutures, which are present in Demyrsus Pascoe, 1872and Siraton Hustache, 1934(Oberprieler & Caldara 2012Lyal 2014;Hsiao & Oberprieler 2020), but how closely related it may be to the cycad-associated genera, Tranes and Miltotranes, is as yet unknown. The similarity of the anchor-shaped sclerite of the endophallus in Paratranes and Tranes lyterioides (Pascoe, 1875) suggests a close relationship between these taxa and that Tranes in its current concept may be nonmonophyletic.…”

“…nov. are quite conspicuous, both in external and in genital characters, and, interestingly, they include the female terminalia, which are usually similar in the same genus in weevils. Especially noteworthy is the difference in the ovipositor, which is much more pronounced than in the other genera of the Tranes group, e.g., Demyrsus and Siraton (Hsiao & Oberprieler 2020), and suggests different modes of oviposition and hence of sites of larval development between the species, such that P. monopticus may lay its eggs into deeper-lying tissues and that its larvae develop in different plant parts than those of P. zimmermani sp. nov..…”

“…Paratranes is here classified in the tribe Orthorhinini, following Anderson et al (2018), who included the Tranes group in this tribe based on the strongly supported relationship between Tranes Schoenherr, 1843 and the orthorhinine genus Vanapa Pouillaude, 1915 found by Shin et al (2017) in a robust phylogenetic analysis of 522 protein-coding genes. Without considering these results, Legalov (2018) recently proposed a separate tribe for the Tranes group, Tranini (incorrectly formed as 'Tranesini'; see Hsiao & Oberprieler (2020)), but his diagnosis of Tranini did not distinguish the group from Orthorhinini, and it further contained characters not present in all the included genera. Pending further and more detailed analysis of the phylogenetic relationships of the Tranes group, it is premature to afford it tribal status in Molytinae.…”

“…Paratranes Zimmerman, 1994 is a weevil genus endemic to Australia, belonging to the Tranes group of Orthorhinini Jekel, 1865 (Anderson et al 2018) or placed in its own tribe, Tranini (Legalov 2018; corrected from 'Tranesini' by Hsiao & Oberprieler (2020)). Unlike the other genera of the Tranes group, which are mostly associated with cycads, Paratranes weevils are associated with grasstrees (Zimmerman 1994;Oberprieler 1995Oberprieler , 2004Oberprieler & Caldara 2012;Anderson et al 2018), having been taken at the base of flower stalks and amongst young leaves (Froggatt 1896(Froggatt , 1907Lea 1898;Mulder 1964;Hawkeswood 1985).…”

Taxonomic Revision of the Genus Miltotranes Zimmerman, 1994 (Coleoptera: Curculionidae: Molytinae), the Bowenia-Pollinating Cycad Weevils in Australia, with Description of a New Species and Implications for the Systematics of Bowenia

“…The method of specimen preparation and measurements follow Hsiao and Oberprieler [ 12 ]. Photographs were mainly taken using a Leica DFC500 camera mounted on a Leica M205C stereomicroscope, except that photographs of the dorsal habitus of M. prosternalis were taken using a Dun Inc. BK Lab Plus system.…”