Review of the genera of Conoderinae (Coleoptera, Curculionidae) from North America, Central America, and the Caribbean
Author
Anzaldo, Salvatore S.
School of Life Sciences, PO Box 874501, Arizona State University, Tempe, AZ, 85287 - 4501, USA
sanzaldo@asu.edu
text
ZooKeys
2017
2017-07-07
683
51
138
http://dx.doi.org/10.3897/zookeys.683.12080
journal article
http://dx.doi.org/10.3897/zookeys.683.12080
1313-2970-683-51
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Piazurini Lacordaire, 1865: 144
Classificatory history and current circumscription.
This tribe was originally characterized by
Lacordaire (1865
: 144) for the genera
Cratosomus
,
Pinarus
, and
Piazurus
in recognition of the strongly canaliculate prosternum, the
"gutter-like"
modification to the mesoventrite and the clavate, non-carinate hind femora that do not or only slightly exceed the abdominal apex.
Heller (1906
: 31) produced a key to
Piazurini
that includes 8 of the 12 currently recognized genera - not included are
Lobops
,
Latychellus
Hustache, 1938,
Hedycera
, and the Old World
Guiomatus
- based largely on the relative size of abdominal ventrites and the amount that they ascend, relative lengths of funicular articles, and the construction of the mesoventrite.
The monotypic South American genus
Hedycera
is moved to the
Piazurini
despite the occurrence of the genus outside the geographic focus of this paper. The exposed pygidium that is not completely visible in dorsal view, the large triangular tooth on the hind femur, the transverse posteromedial depression on the metaventrite (discussed further below), and the unarmed femoral apices place the genus not only in the
Piazurini
but in a hypothesized clade containing
Piazurus
,
Pseudopiazurus
Heller, 1906,
Pseudopinarus
Heller, 1906 and the South American
Piazolechriops
Heller, 1906.
Hedycera megamera
Pascoe, 1870 would key out to couplet 7 of
Heller's
1906
key (containing
Pseudopinarus
and
Piazolechriops
), for having abdominal segments only slightly ascending, abdominal segment 2 not being longer than 3 and 4 combined, and the presence of "
superciliarleisten
", referring to the arcuate carina at the vertex of the head found in most members of these genera (though not in a few species of
Pseudopinarus
), a greatly elongate antennal funicular article 2, and a slender rostrum.
Hedycera
can be differentiated from these by the shape of the pronotum in dorsal view, which is widest in the anterior half just before the subapical constriction, and in having elongate setae on the antennal funicular articles. When originally describing the monotypic genus,
Pascoe (1870)
stated that it was most closely related to
Piazurus
, which was later agreed with by Champion (1906: 713).
Hedycera
is the first genus separated in
Heller's
key (1895) for having similar-sized abdominal ventrites 2, 3, and 4, but is not treated further in that publication. In the catalogs of
Hustache (1934
: 45) and
Blackwelder (1947
: 884)
Hedycera
is listed under the otherwise entirely Old World-distributed conoderine tribe
Mecopini
Lacordaire, 1865 and was moved to
Lechriopini
in
Wibmer and
O'Brien
(1986
: 19), without a justification provided in either placement.
Variation in key character systems.
The modification to the mesoventrite in the genera treated here in the
Piazurini
varies from being a cup-shaped receptacle (as in
Lobops
; Fig.
2
) to structured similarly to a cup-shaped receptacle but with the posterior margin flattened and depressed at least slightly below the level of the lateral margins of the channel (Figs
3
,
4
) allowing the rostrum to pass through to the metaventrite if long enough. The eyes are often smaller and more separated and are not or not as sharply acuminate ventrally or laterally inflexed (Figs
38
,
39
) as in many
Lechriopini
and
Zygopini
, but can be quite large and contiguous or subcontiguous (Figs
40-41
), taking up most of the surface of the head as well as be slightly ventrally acuminate to slightly laterally inflexed. The pygidium is exposed but not entirely visible in dorsal view (somewhat
concealed
from above by the elytral apex; e.g. Fig.
68
), usually only visible completely in posterior or ventral view. Abdominal ventrites are flat to slightly, evenly ascending. The vestiture consists of thick setae to small scales, usually not covering most of the body surface except in
Lobops
, which has large, flat and round scales. The femora are at least slightly clavate, the hind femur is without a lateral carina and lacks teeth at the mesal and lateral apical faces (Fig.
60
; in most lechriopines and zygopines, a tooth is usually present at the mesal and/or lateral face of the femoral apex on the middle and/or hind legs as in Figs
61-63
), and several genera have a large, laterally compressed, triangular ventral tooth. This large triangular tooth is also found in other conoderine tribes (e.g.
Menemachini
Lacordaire, 1865;
Campyloscelini
Schoenherr, 1845) as well as other groups of weevils (e.g.
Hylobiini
Kirby, 1837). Despite this homoplasious distribution in
Curculionidae
it likely represents a single origin within the
Piazurini
, with the genera having it also sharing additional characters; it is also not found in other New World
Conoderinae
, making it useful for diagnosing the group of Piazurines that bear it.
Additional characters of potential phylogenetic significance.
The metaventrite posteromedially has a transverse depression, not with a narrow longitudinal sulcus extending variably anteriorly as in most
Lechriopini
and
Zygopini
(but many species of
Cratosomus
have a broad longitudinal depression). The antennal club is typically more spherical to ovoid, with the suture between at least articles 2 and 3 sinuate (but also found in a few lechriopines and zygopines). A mesal process of the procoxae is absent in most piazurines and found in many lechriopines and zygopines (though present, among the Central American species observed, in
Pseudopinarus
,
Lobops bonvouloiri
(Hustache, 1932), and in the species
Piazurus alternans
Kirsch, 1875). Sclerolepidia are absent in
Piazurini
(
Lyal et al. 2006
: 237). Additionally, piazurines are quite different behaviorally from the remainder of the New World
Conoderinae
, typically being less active in the daytime and no species are known to be part of the several widespread mimicry complexes found in the tribes
Lechriopini
and
Zygopini
(
Hespenheide 1995
).
Diversity and distribution.
Fifty-two species are currently known from north of South America in five genera. Six additional genera are known only from South America, and one genus,
Guiomatus
, occurs in Papua New Guinea.