Dipnotyphlus, Colonnelli, 2014

Colonnelli, Enzo, 2014, Apionidae, Nanophyidae, Brachyceridae and Curculionidae except Scolytinae (Coleoptera) from Socotra Island, Acta Entomologica Musei Nationalis Pragae 54, pp. 295-422 : 329-330

Dipnotyphlus gen. nov.

Type species. Dipnotyphlus laminiscapus sp. nov., by present designation.

Description. Body small, rather elongate, strongly punctured. Vestiture of sparse setae intermingled with translucent earthy scales at base of rostrum and on legs. Head globose, eyeless. Rostrum rather thick, elongate, dilated at base and in profile tapering towards apex, its level at base higher than that basal one of head. Antennae short, scape very strongly and abruptly widening apicad of middle and with laminar setose expansion situated above insertion of pentamerous funicle; antennomere I of which is only slightly transverse, club large and with numerous erect stiff setae. Pronotum elongate, its base finely marginate. Scutellum invisible. Elytra navicular, very finely carinate at base, shoulders absent. Striae formed by very large deep subrectangularly elongate punctures, intervals narrower than striae. Femora clubbed, edentate, quite compressed, profemora larger than meso- and metafemora. Tibiae short and thick, apical uncus strong. Tarsi slender, tarsomere III not bilobed, claws minute, free. Procoxae almost contiguous and closer to posterior than to anterior margin of prosternum, mesocoxae separated by an interval almost equal to their diameter, metacoxae widely separated by a distance about the same length as the anteriorly truncate metaventrite. Abdominal ventrites I and II elongate, III and IV very short, their combined length about half that of ventrite II, ventrite V rather elongate and crescent-shaped.

Differential diagnosis. It is somewhat difficult to place this peculiar new genus into one of the tribes in which Cossoninae are divided at the moment, taking into account also that the boundaries between cossonines and molytines are quite unclear ( HOWDEN 1992, COLONNELLI 2010, BELLÒ et al. 2011). Dipnotyphlus gen. nov. is considered to belong to the Onycholipini Wollaston, 1873 , a cossonine tribe composed of fairly different genera with which the Socotran one shares some of the main characteristics. Among the Cossoninae , the new genus is rather isolated, in addition to being eyeless which is rather uncommon in members of this subfamily, due to the unusual shape of the scape, pentamerous funicle, antennal club with long setae, rostrum dilated at base, navicular elytra with regular rows of punctures, and profemora obviously larger that the remaining ones ( Figs 36–38 ). Similar laminar antennal dilatation is found in some myrmecophilous Nitidulidae ( AUDISIO 1993) , e.g. the genus Amphotis Erichson, 1843 , the function of which is supposedly to protect the insect from a possible attack by ants. Perhaps the expanded scape of Dipnotyphlus gen. nov. has the same function.

Etymology. The name of the new genus, is composed of the ancient Greek ‘δειπνέω’ meaning ‘to eat’ and ‘τυφλός’ meaning ‘blind’, and refers to the probable root-feeding behaviour of its single eyeless member. Gender is masculine.

Figures

Figs 36–39.Dipnotyphlus laminiscapus sp. nov., holotype.36 – habitus; 37 – habitus in side view; 38 – head and front tibiae; 39 – spermatheca.