Theognete

Anderson, Robert S., 2010, A taxonomic monograph of the Middle American leaf-litter inhabiting weevil genus Theognete Champion (Coleoptera: Curculionidae; Molytinae; Lymantini) 2458, Zootaxa 2458 (1), pp. 1-127 : 6-7

Classification of Theognete

The genus Theognete is placed in the tribe Lymantini of the subfamily Molytinae ( Alonso-Zarazaga & Lyal 1999) . Lymanini are best characterized by the placement of the eyes, which are located beyond the constriction that demarcates the division between the head and the rostrum, thus appearing as if situated on the rostrum. The eyes vary in extent of development throughout the tribe, from absent or composed of a few very small facets to well-developed, large and distinct. The female genitalia lack styli on the coxites, and eyeless members of the group can thus be distinguished from superficially very similar eyeless Anchonini and Cossoninae , which possess such styli ( Howden 1992). Also, in Anchonini and most Cossoninae the eyes, if present, are located distinctly posteriorly of the head-rostrum constriction and thus are situated on the globular head. Theognete species have a more rounded and globose habitus than nearly all other lymantines, with the exception of an undescribed genus from Guatemala and Honduras that is distinguishable from Theognete by the contiguous middle coxae and the structure of the female genitalia, and the elytra of most species lack welldefined striae and are impunctate. The eyes are well-developed and distinct, and all species have at least some dorsal vestiture, although the density, form, length and aspect of the scales can vary extensively from recumbent and simple to erect and plumose. The form of the thoracic sterna is distinctive in many species and also allows for the division of Theognete into what are considered to be natural species groups. Many species, particularly in the T. tzotzil species group, are very similar in external structure, differing very slightly only in subtle aspects of pronotal and elytal punctation or vestiture, but differences in the structure of the aedeagus suitably differentiate such species. The sexes are differentiated in Theognete as they are in other Curculionidae , males being distinguishable by flat to concave abdominal ventrites 1 and 2 and by a shorter, more robust apical portion of the rostrum, beyond the point of antennal insertion, whereas females have more uniformly convex ventrites 1 and 2 and a longer and more slender, often shiny, apical portion of the rostrum beyond the point of antennal insertion. A few species have secondary sexual characters of the legs and abdomen, and occasionally the genitalia are extruded sexing preserved specimens.

Species of Theognete are highly localized in their geographic distributions, and there is little basis for analysis of geographic variation. Most species are known from only one or a few proximal localities. Structurally different sympatric forms are usually very distinct and clearly represent different species.