Galapagonotus cuneiformis, Waterhouse. Subsequent

ANDERSON, ROBERT S. & LANTERI, ANALIA A., 2000, New Genera and Species of Weevils from the Galapagos Islands, Ecuador, and Cocos Island, Costa Rica (Coleoptera; Curculionidae; Entiminae; Entimini), American Museum Novitates 3299, pp. 1-16 : 1-3

as O. cuneiformis Waterhouse. Subsequent publications continued to consider this species a member of Otiorhynchus (Waterhouse,

1 Research Associate, Canadian Museum of Nature, P.O. Box 3443, Station D, Ottawa, ON. K1P 6P4, Canada. Email: [e-mail]

2 Departamento Cientifico de Entomologia, Museo de La Plata, Paseo del Bosque, s/n 1900, La Plata, Argentina. E-mail: [e-mail]

1877; Linell, 1898) until Van Dyke (1953), in his review of the beetles of the Galapagos, questioned this placement and assigned the species to Amphideritus Schoenherr , a South American genus of Naupactini . Franz (1985), citing information passed on to him by Kuschel, suggested that Amphideritus sensu Van Dyke from the Galapagos actually belonged in Barynotini . Subsequently, Kuschel (1986: 67) placed the species name cuneiformis as incertae sedis within Barynotini and noted that it was not assignable to any described genus and that a new genus needed to be described to accommodate it.

We agree with the conclusions of Kuschel and here describe a new genus, Galapagonotus Anderson and Lanteri , to accommodate this species. In addition, in attempting to establish the phylogenetic relationships of Galapagonotus , we examined specimens of three undescribed species of an undescribed genus from Cocos Island, off the southwestern coast of Costa Rica. We here describe a second new genus, Coconotus Anderson and Lanteri , to accommodate them.

In addition to the description of the new taxa, we review what is known of their distribution and natural history and attempt to ascertain their phylogenetic relationships. Both Galapagonotus and Coconotus appear to be endemic to the Galapagos Islands and Cocos Island, respectively; however, despite their close proximity, they do not appear to be very closely related. That said however, the precise phylogenetic relationships of each genus are unclear.

CLASSIFICATION OF CURCULIONIDAE

As is well known, the higher classification of the Curculionoidea is in continuing flux (Kuschel, 1995; Marvaldi, 1997; Morrone, 1997; Thompson, 1992; Zimmerman, 1993, 1994a, 1994b). Unfortunately, most of these works emphasize classification and relationships at the subfamily and family-group levels and, as far as we are concerned, do not adequately address the tribal levels, particularly within the subfamilies of Curculionidae . Regardless, we here follow the consensus classification proposed by Morrone (1997), which with respect to broad-nosed weevils follows Marvaldi (1997, 1998) in recognizing the Entiminae as a large (1150 genera; 12,200 species) monophyletic subfamily of the Curculionidae accommodating the majority of taxa of the traditional Adelognatha. Marvaldi (1997) justified the monophyly of Entiminae by the presence of two character states in the larvae: (1) maxillary mala with four ventral setae, and, (2) antennal sensorium wider than long and cushionlike. Also based on characters of larvae, she further proposed a natural division of Entiminae into five tribes: Pachyrhynchini , Ectemnorhinini , Alophini , Sitonini , and Entimini (Marvaldi, 1997) . In a second paper, she attempted to group taxa within the diverse Entimini into three informal, but possibly natural, subsets, which she called A, B, and C (Marvaldi, 1998). Unfortunately, the division of Entimini into these groups was based only on characters of the larvae and examination of only a very limited diversity of taxa. Clearly, as Marvaldi indicated, additional work needs to be done, especially using characters of the adult stage and incorporating a broader diversity of taxa, to see how well (or even if) these groupings hold. Nevertheless, this is the only recent study attempting to resolve relationships within Entimini , which otherwise is based on the artificial and outdated system of Lacordaire (1863, 1866). While it is beyond the scope of this paper to examine relationships among all Entimini , some comments can be made concerning characters of apparent use in the classification of this large and difficult group within the New World.

We examined a variety of taxa of New World Entimini in attempting to place the two new genera described herein. Unfortunately, despite the number of recent publications on the classification of Curculionidae (e.g., Kuschel, 1995; Morrone, 1997), none have attempted to place the New World genera within higher categories. Only the checklists of O’Brien and Wibmer (1982), Wibmer and O’Brien ( 1986), and supplements (O’Brien and Wibmer, 1984; Wibmer and O’Brien, 1989), which in general follow Lacordaire (1863, 1866), explicitly and comprehensively assign New World genera (and their included species) to higher categories. This lack of naturally defined subtribes (oth- er than those of Lacordaire), and the lack of clear relationships with other genera means that more detailed placements of both Galapagonotus and Coconotus remain tentative.

We know of no Entimini that appear similar to, or closely related to, Galapagonotus . Galapagonotus may prove related to the Eustylus group of genera based on similarities in the mandibular structure (multisetose, with a large prominent scar and a poorly developed interior cutting edge); similarly emarginate epistoma; metatibia with glabrous apical bevel; and similar female genitalia. Despite the fact that most other Galapagos weevils appear to have relationships directly with the South American mainland, we cannot establish such a relationship for Galapagonotus at present.

Relationships of Coconotus also are unclear. Coconotus may be related to Lachnopus Schoenherr from the West Indies (based on comparison of Lachnopus floridanus Horn ) or Exophthalmus Schoenherr , both of which have similar mandibular structure (multisetose, small scar, well-developed interior cutting edge), lack of scales on the antennal scape, similar glabrous metatibial bevel, and similar form of the apex of the metatibia. However, other features, such as the presence of styli on the hemisternites, and the distinct form of most other species of Lachnopus , may suggest otherwise. On the other hand, a very different relationship with the genus Rhyncogonus Sharp from the islands of Polynesia is suggested by some features, particularly the somewhat flattened habitus of C. williamsi . Both sexes of Rhyncogonus , and Coconotus females, share a carinate or keeled lateral elytral margin (although in Coconotus this is restricted to the humeral region only). Other features, such as mandibular form, form of the apex of the metatibia, and lack of scales on the antennal scape, support a relationship with Rhyncogonus ; however, Coconotus differs in the structure of the antennal scrobe (open posteriorly in Rhyncogonus but directed below the eye in Coconotus ), lack of a stylus on the hemisternites (present in Rhyncogonus ), and the metatibia with a broad glabrous apical bevel (absent in Rhyncogonus ). We feel that these features shared with Rhyncogonus are likely the result of convergence and that the affinities of Coconotus lie somewhere within