 |
| Dematotrichus gen. nov. Dorsal views of the male holotype and one female paratype of Dematotrichus hirtus sp. nov. (a), the male holotype of D. pubescens sp. nov. (b), the male holotype of D. capillaris sp. nov. (c), the male holotype and one female paratype of D. comatulus sp. nov. (d), and the male holotype and one female paratype of D. villosus sp. nov. (e). Gómez-Zurita. 2022 twitter.com/GomezZuritaLab |
Abstract
The monophyletic group of species around Dematochroma pilosa Jolivet, Verma & Mille is identified in this work by combining information from mitochondrial DNA data and morphological features. A series of defining traits diagnosing this species assemblage from its closest phylogenetic relatives, including the genera Thasycles Chapuis and Atrichatus Sharp, is used to argue for its taxonomic separation and propose a new genus, named Dematotrichus gen. nov. Both Dematochroma pilosa and Montrouzierella hispida Jolivet, Verma & Mille are transferred to the new genus as D. pilosus (Jolivet, Verma & Mille) comb. nov. and D. hispidus (Jolivet, Verma & Mille) comb. nov., and 11 new species are described: D. capillaris sp. nov., D. capillosus sp. nov., D. comans sp. nov., D. crinitus sp. nov., D. comatulus sp. nov., D. hirtus sp. nov., D. hirsutus sp. nov., D. horridus sp. nov., D. pubescens sp. nov., D. setosus sp. nov. and D. villosus sp. nov. The work includes an identification key for all the species in the new genus.
Key words: Dematotrichus gen. nov., Dematochroma, Eumolpinae, island radiation, New Caledonia
 |
| Dorsal views of the male holotype and one female paratype of Dematotrichus hirtus sp. nov. (a), the male holotype of D. pubescens sp. nov. (b), the male holotype of D. capillaris sp. nov. (c), the male holotype and one female paratype of D. comatulus sp. nov. (d), and the male holotype and one female paratype of D. villosus sp. nov. (e). |
Dematotrichus gen. nov.
Diagnosis. One particularly remarkable feature of this genus in the context of the diversity of New Caledonian Eumolpinae, which shall help recognizing it right away, is the relatively homogeneous dorsal pubescence, only thinner perhaps on head. Such type of vestiture is not common at all among members of the tribe Eumolpini, although a few other genera or evolutionary lineages of New Caledonian Eumolpinae exhibit some degree of dorsal pubescence. However, these groups can be told apart very easily based on the shape of their pronota. One of the closest relatives to Dematotrichus gen. nov. is the genus Thasycles Chapuis. These genera show some external similarities, including the presence of setae on pronotum and elytra, but in Thasycles they are sparser and not uniform, mostly at sides and apex of elytra, and have a distinctive pronotum, transverse, with flat anterior angles (Gómez-Zurita & Pàmies-Harder, 2022). The species of Taophila Heller have some pubescence on elytra and often on pronotum, but it is also much sparser and/or patchier, and they have an unmistakable body structure, in good part because of the shape of pronotum, as well, narrower than elytra, about as long as wide, narrowing at both ends, and without lateral suture or very finely margined laterally (Platania & Gómez-Zurita, 2022). Tricholapita Gómez-Zurita & Cardoso have more generalized pubescence on both pronotum and elytra, but once again, the pronotum is very different from Dematotrichus (or any other known related genus), showing three and most often two prominent teeth at sides (Platania et al., 2020). Samuelsonia pilosa Jolivet et al., 2007a, S. mayonae Jolivet, Verma & Mille, 2010 (in Jolivet et al., 2009) and a group of undescribed species related to them also have pubescent dorsum, but these are immediately recognizable because of their much smaller size (2–3× smaller), typically greenish or cupreous dorsal shine and pronotum not much narrower than elytra, widened posteriorly. The last known hairy representative of New Caledonian Eumolpinae, Dematochroma doiana Jolivet et al., 2007b, shows the same dense uniform pubescence on dorsum as all the species of Dematotrichus, and the penis has similar appearance, but the pronotum is very different, transverse, with anterior and posterior borders of similar length and anterior angles not compressed at sides of head.
Derivatio nominis. The generic name is composed of the same Greek root word for Dematochroma, Demato- (perhaps with the original meaning of bundle or bond; Brown, 1954), combined with a transliteration derived from the Greek word θρίξ or hair, -trichus, of intended masculine gender and in reference to the hairy dorsum of all species known to belong to this genus.
JesúS Gómez-Zurita. 2022. Integrative Systematic Revision of A New Genus of Eumolpinae (Coleoptera: Chrysomelidae) endemic to New Caledonia: Dematotrichus gen. nov. and its numerous new hairy species. Systematics and Biodiversity. 20(1); 1-28. DOI: 10.1080/14772000.2022.2084471
twitter.com/GomezZuritaLab/status/1552197512190218240