Nehrodistus Reitter, 1912

Christoph Germann, Sofia Wyler & Marco Valerio Bernasconi, 2017, DNA barcoding of selected alpine beetles with focus on Curculionoidea (Coleoptera), Revue suisse de Zoologie 124 (1), pp. 15-38 : 27

Subgenera Nehrodistus Reitter, 1912 , Misenatus Reitter, 1912 , Melasemnus Reitter, 1912

From subgenus Nehrodistus the four species O. armatus Boheman, 1842, O. turca Boheman, 1842, O. obesus Stierlin, 1861 , and O. pesarinii Diotti, 2008 are included. These species did not form a monophyletic clade, and species of other subgenera e.g. Otiolehus cluster within ( Fig. 1 , Supp. 1). This may show that a natural group of relatives including species of Nehrodistus – mainly characterised by the teethed femora, the rugose pronotum, the spotty distributed scales on elytra, these deprived of hairs and the slender antennae with second article almost twice as long as first – may include species of other subgenera as well. However, the detailed relationships among these species are not supported by sufficient bootstrap values and remain therefore questionable with our COI sequence data.

In the case of O. armatus the sample from the Ligurian coast differed substantially (K2 distance: 0.077) from the one taken on Ischia island. Just recently Diotti (2008) revised the species close to O. armatus and described with O. pesarinii a new species from Basilicata. The subsequent comparison with a paratype specimen provided by the author, the con-specificity of the sample specimen from Ischia Island with O. pesarinii could be confirmed.

Interesting and surprising from the morphological point of view are Otiorhynchus lugens (Germar, 1817) and O. ovalipennis Boheman, 1842 as highly supported sister taxa (ML and NJ both 99). Where a species with a single tooth on the femora, a slender rostrum, eyes laterally standing, elytra dull and deprived of hairs, and robust legs (subgenus Misenatus ) is sister to O. ovalipennis ( Melasemnus ) with several additional small rasp like teeth on fore femora, a short rostrum, dorsally oriented eyes, shiny elytra with hairs, and gracile slender legs may represent unreliable characters for morphological estimates on phylogenetic relationships. The differences regarding teeth on femora is also present in the – although in both our analyses moderately supported – clade of O. magnicollis Stierlin, 1888 + O. thaliarchus Reitter, 1914 ( Choilisanus Reitter, 1912 with unarmed femora, versus Melasemnus with teeth, often even several on fore femora). Another example for the absence and/or presence of teeth is the clade Metopiorrhynchus (teeth present) + Aranihus (teeth absent, or minute and often overlooked as in O. ligneus!) + pars Phalantorrhynchus (teeth absent) + Nihus (teeth absent), however with lower support (ML: 58; NJ: 61).

Figures

Fig. 1. Best Maximum Likelihood tree as selected by MEGA) based on COI sequences of 142 samples of Curculionoidea (Chrysomelidae obtained by using MEGA 6. Values (over 50 %) of bootstrap support from 100 nodes.