Rhamphus oxyacanthae (Marsham, 1802)

Diotti, Luciano, Caldara, Roberto & Toševski, Ivo, 2021, Description of two new species of Rhamphus related to R. oxyacanthae (Curculionidae, Curculioninae, Rhamphini) from Italy based on a morphological study supported by molecular data, Zootaxa 4995 (1), pp. 111-128 : 121

Remarks on Rhamphus oxyacanthae and R. monzinii

We studied specimens of R. oxyacanthae from across continental Italy and sequenced specimens from Lombardia (Fino Mornasco), Piedmont (Giaglione), Emilia (Passo Cirrone) and Basilicata (Accettura, monte Paratiello). According to the morphology and mtCOI, all of them belong to the same species from the type locality ( England) and were collected on Crataegus (data not shown).

Rhamphus monzinii was previously only known from seven specimens from the type series collected at Giaglione (Piedmont, northern Italy) on Salix sp. and Betula sp. We found a large series of specimens of this species at Montoggio (Piani di Creto, Liguria, northern Italy) on two different occasions (23.VI.2018 and 19.VI.2019), only on Prunus spinosa , growing near plants of Crataegus monogyna , on which on the contrary we collected specimens of R. oxyacanthae and R. subaeneus . Therefore, it is likely that R. monzinii was collected on Salicaceae and Betulaceae in the type locality only occasionally, as also suggested by Pesarini & Diotti (2012), when they rightly reported that their new species is morphologically more related to R. oxyacanthae living on Rosaceae than to R. pulicarius living on Betulaceae and Salicaceae . This relationship seems also confirmed by preliminary molecular studies (I. Toševski, pers. obs.).

No differences in mtCOI were found between a paratype of R. monzinii and specimens from Liguria. Although this species is similar to the other three taxa here treated, it is possible to separate it from them by more numerous characters, such as the shorter rostrum, the scape of the antennae reddish as are the other segments of the funicle, the first funicular segment being more globose than in the other species (arrows in figs. 14 and 15). Moreover, the shape of the elytra is different (fig. 6): they are elliptical, with less prominent humeri, only slightly wider than the pronotum, widest more towards the base and more globose. Finally, the uncus of pro- and metatibiae is smaller (arrow in fig. 12). With regard to this last character, we confirmed its taxonomic relevance as argued by Germann & Colonnelli (2018), who noticed the presence of a very long uncus in R. loebli . We found that R. oxyacanthae and the two new species have a larger uncus than R. monzinii , but smaller than R. pulicarius (arrows in figs. 11-13).

...Continued on the next page