Further study of Cylindridia Casey with descriptions of new species ( Coleoptera : Curculionidae : Baridinae ) With 12 figures

Further support is provided for the occurrence of Cylindridia Casey in the Neotropical realm. The South American Torcus sanguineus Hustache is transferred to Cylindridia (comb. n.). Cylindridia latisquama sp. n., a very similar species and originally included in the type series of T. sanguineus, is described from Argentina and Brazil. Cylindridia andersoni sp. n. is described from Guatemala and Mexico; the species develops inside the culm of Rhychospora sp. cf. macrochaeta (Cyperaceae). The family-group name Torcina Bondar, never satisfactorily distinguished from Limnobaridina Casey and being based on a misidentified type genus, is placed in synonymy with Zygobaridina Pierce (new synonymy).


Introduction
In an earlier paper (Prena 2006), I argued that the ostensibly Neartic genus Cylindridia Casey, 1920 is principally Neotropical but has one isolated species in North America.This conclusion was based on three new species from high elevations in Central America, considered by me as glacial relicts of a formerly more widespread ancestor, and one unidentified species from southern Brazil.Meanwhile, I have seen additional specimens which not only support this conclusion but also help to understand better the existing taxonomic confusion associated with the South American species of this genus.As already suspected in my previous study, it is now confirmed that South American Cylindridia have been described in another genus without making a connection to the Nearctic fauna.Hustache (1939) described at least one Cylindridia species in Torcus Casey, 1922 and placed it in a separate subgenus, Eutorcus, which remained nomenclaturally unavailable because he did not designate a type species for it.I have seen some but not all of his other Torcus species and those do not always belong to Torcus either.The apparently complete reliance on the keys in Casey (1922) explains why Hustache (1950) speculated about a possible synonymy of Sibariopsida Casey, Sibariops Casey, Pseudotorcus Casey, and Torcus, while at the same time disregarding the more senior name of a strikingly similar North American genus.In this paper I transfer one previously described South American species to Cylindridia, describe two new species, and provide an updated identification key for the seven currently known species.Information on C. fuscipes Prena, C. prolixa (LeConte), C. propinqua Prena, and C. rubripes Prena can be found in Prena (2006).

Material and Methods
The study is based on more than 500 specimens of Cylindridia and Torcus of authors.The following codens are used to refer to collections in the text.Hustache, 1950.The Hustache Collection has a male and a female specimen standing under this name, each collected in Tigre, Buenos Aires Province, Argentina by M. J. Viana.The type series included at least one other male with fully developed prosternal spines, probably from Luján in the same province, which was not examined by me.The USNM has matching specimens from the same region.The entire material shows that Hustache's male paratype in the MNHN is a distinct species and conspecific with Cylindridia "sp.A" in Prena (2006).

Diagnosis:
Cylindridia andersoni can be recognized by the conspicuous elytral fasciae, which occur in no other known species of Cylindridia.The color pattern is less well defined in the Oaxaca specimens but the male genitalia are identical in both populations.

Description:
Derm shiny black, appendages rufescent to various degrees, prosternal spines yellowish red; white pyriform setae present on pronotal flank, metepisternum and femur, above eye, and in two elytral fasciae (Fig. 1); rostrum slightly (males) or conspicuously longer (females) than pronotum, very slightly (female) or distinctly (male) curved throughout (Fig. 5), lamellar process ventrad of antennal insertion not angularly projected; antennal club not longer than distal four funicular segments combined; frons with erect setae above eye; pronotum slightly wider than long, sides subtly curved in basal half, roundly constricted apically and tubulate in front; sides of aedeagus gradually converging toward base, apex truncate and medially slightly produced, base of apodemes fused with, but not subsumed in, body of aedeagus; apodeme slightly longer than body of aedeagus (Fig. 9), internal sac short, basal sclerite 2-pronged and minute, tegmen with parameroidal lobes and basal apodeme of subequal length, male sternite 9 with distal appendices unequal; total length 3.0-3.9mm, standard length 2.7-3.6 mm.

Distribution:
The species is known from high elevations in Guatemala and Mexico.

Plant associations:
The specimens from Guatemala were extracted from the culm of a Rhynchospora species, possibly R. macrochaeta Steudel ex Böckeler, Cyperaceae.

Epithet:
The species is named after my Canadian friend and colleague Robert S. Anderson, who found the species inside the host plant.

Diagnosis:
Cylindridia latisquama is very similar to the equally rufous (and sympatric) C. sanguinea, and both species were represented in the type series of the latter.The simplest way to separate the two species is the dorsal vestiture, which consists of wide, pyriform setae in C. latisquama and of slender, piliform setae in C. sanguinea.Another striking though internal difference is that C. latisquama has the basal part of the apodemes subsumed into the body of the aedeagus (Fig. 10), which is not the case in C. sanguinea (Fig. 11).

Description:
Derm reddish brown to brown, head and rostrum darker, matte; whitish pyriform scales present but not locally clustered (Fig. 2); rostrum slightly (males) or conspicuously longer (females) than pronotum, very slightly (female) or distinctly (male) curved throughout (Fig. 6), lamellar process ventrad of antennal insertion not angularly projecting; antennal club slightly longer than distal four funicular segments combined; frons with appressed setae above eye; pronotum slightly wider than long, sides subparallel in basal half, roundly constricted apically and subtubulate in front; sides of aedeagus parallel, apex blunt and medially slightly produced, base of apodemes subsumed into body of aedeagus, remaining free section of apodeme shorter than body of aedeagus (Fig. 10), internal sac more than half length of apodeme and lobed, basal sclerite absent, tegmen with parameroidal lobes and basal apodeme of subequal length, male sternite 9 with distal appendices unequal; total length 3.5-5.6mm, standard length 3.2-5.3mm.

Distribution:
The species is known from southern Brazil and Argentina.

Epithet:
The name is a Latin composite noun in apposition based on squama (scale) and latus (wide).

Material examined:
Holotype male, dissected, labeled "BRASIL: Nova/ Teutonia, Santa/ Catarina, X As presently defined, Cylindridia includes seven species which, taken together, show a noticeably disjunct distribution in the New World.All lowland records in each hemisphere are from the temperate zone, and all records within the tropics are from mid and high elevations in Central America.Even though the newly added data improve our understanding of these slender, sedge-associated species, their morphological distinctness from other genera remains unclear.This problem has been mentioned previously in connection with the Nearctic genus Dirabius Casey, 1920(Prena 2006).Several morphologically similar species occur in the temperate zone of South America but differ in details which are difficult to interpret with the presently available material.This includes, for example, the other two species described by Hustache (1950) in his unavailable subgenus Eutorcus.One of them, Torcus variabilis Hustache, 1950 (Fig. 4), is well represented in collections (e.g., AMNH, CWOB, MNHN, and USNM) and was studied in greater detail.Unlike typical Cylindridia, T. variabilis has a distally tapered aedeagus (Fig. 12), which occurs regularly in other sedge-and grass-associated baridines, particularly in the Lipancylus/Parallelosomus complex.Further collections as well as biological and molecular data are needed to clarify whether Cylindridia indeed evolved through biogeographic segregation of a formerly more widespread temperate fauna or represents species with convergently elongate body shapes derived from unrelated ancestors in cooler climates.