Cachiporrini, a remarkable new tribe of Lamprosomatinae (Coleoptera, Chrysomelidae) from South America

Abstract A new genus and species of Lamprosomatinae, Cachiporra extremaglobosa Chamorro & Konstantinov, is described from Brazil. A new tribe, Cachiporrini, is proposed. The first phylogenetic analysis of Lamprosomatinae based on adult morphological caharacters is conducted. Comparisons are made among lamprosomatine tribes and genera. A key to tribes is provided.


Introduction
As taxonomists we can only hope to make the kind of discoveries that prompt suspended awe and prolonged excitement. Such was our reaction when we stumbled upon this new lamprosomatine genus buried within the Cryptocephalinae addenda drawers of the Coleoptera collection at the National Museum of Natural History (NMNH), Smithsonian Institution. Confi rmation of this taxon as new was facilitated by the comprehensive chrysomelid collection at NMNH, by the relatively small number of higher-level taxa in Lamprosomatinae, and by the comprehensive studies by Monrós (1956Monrós ( , 1958 on the group.
Monrós devoted much of his short life and taxonomic expertise to the study of this group of small, round, and shiny beetles. Th erefore, it was surprising and somewhat ironic that these specimens are from the Monrós collection acquired by the NMNH in 1959. It is fair to state however, that the Monrós collection is extensive and would require many consecutive lifetimes to study it all.
All lamprosomatines are highly convex and ventrally fl attened [species of Cryptocephalinae, including Chlamisini, sister taxon to lamprosomatines (Farell 1998), are cylindrical and not ventrally fl attened], they are shiny and usually iridescent (cryp- tocephalines are rarely iridescent), their abdominal ventrites are all the same width medially with sternal longitudinal muscles within ventrite 4 [constricted ventrite 4 appearing hidden between ventrites 3 and 5 and sternal longitudinal muscles lacking in cryptocephalines (Kasap and Crowson 1976)]; females lack a fovea or egg-depression on ventrite 5 (present in cryptocephalines); and antennal grooves are present on the prosternum (feature also present in Chlamisini and Ischiopachina of Clytrini).
Upon discovery, Cachiporra could not be placed into any previously recognized lamprosomatine tribe. Clavate antennae are common in many camptosomata (e.g. Chlamisini, Clytrini, Lamprosomatini, but not in Cryptocephalini) (Figs 7,8), however, Cachiporra is the fi rst known camptosomata with capitate antennae represented by completely fused antennomeres forming an abrupt terminal bulb (capitulum), which is much wider than preceding antennomeres (Figs 16, 18; autapomorphy of Cachiporrini, character 2 state 0). Th is kind of club is very uncommon in Chrysomelidae; it is known in only a few fl ea beetle (Alticini) genera commonly living in relatively dense substrate, such as leaf litter or moss cushions (e.g., Clavicornaltica Scherer, Kiskeya Konstantinov and Chamorro-Lacayo)  and a few Hispini.
A phylogenetic analysis of Lamprosomatinae was undertaken to fi nd taxonomic position for Chachiporra within the subfamily. Designation of a new tribe was considered appropriate and justifi ed to accommodate this new genus from Brazil. Current higher-level classifi cation is based on Monrós's (1956Monrós's ( , 1958 interpretation of relationships. Th e fi rst evolutionary relationship among Lamprosomatinae is here inferred based on cladistic principles.

Taxon sampling and outgroup
Th is study includes 12 of 14 lamprosomatine genera in 4 tribes (Tables 1 and 3). Exema Lacordaire and Melittochlamys Monrós (Chlamisini) were selected as outgroup to determine character polarity. All examined material is from the National Museum of Natural History (NMNH), Smithsonian Institution, Washington, DC.

Phylogenetic analysis
Th e data matrix was created using MacClade 4.08 (Maddison and Maddison 2000) and analyzed using PAUP* (beta test version) (Swoff ord 2003). Heuristic search was implemented using stepwise addition and 1000 random addition sequence replicates, 5 trees held at each step and Tree-Bisection-Reconnection (TBR) branch swapping algorithm. Nodal support for the preferred topology based on the given dataset was determined by bootstrapping (Felsenstein 1985) and Bremer support indices (Bremer 1988(Bremer , 1994. Bootstrapping was carried out with 500 replicates and random-taxon addition. Decay or Bremer support indices were calculated by executing in PAUP*a MacClade generated batch fi le of 20 replicate heuristic searches and random-taxon addition for each constraint tree.

Results
Five equally parsimonious trees resulted from this analysis (Figs 23-27) of length 55 (CI: 0.80; RI: 0.82; RC: 0.65). A strict consensus tree is shown on Fig. 28. All topological results support the designation of a new tribe, Cachiporrini. Both Bremer and bootstrap values (respectively, separated by comma) strongly support the monophyly of Lamprosomatinae and Lamprosomatini. Th e placement of Sphaerocharis and the monophyly of Neochlamysini remains uncorroborated in the strict consensus. Majority-rule consensus tree retains a monophyletic Neochlamysini with Sphaerocharini as the sister taxon to Lamprosomantini (Figs 29-31). A majority-rule consensus cladogram is shown with distribution of unambiguous characters in Fig. 29 and ambiguous characters under slow (Fig. 30) and fast (Fig. 31) optimization.  With stridulatory fi le (device) on distal border of last ventrite (Fig. 5); last ventrite not excised in shape of arc. Pygidium completely covered by elytra. Scutellum acutely triangular, small to very small (Fig. 3) (Figs 16, 18).
Pronotum basally sinuate (Fig. 15), medially extending posterad beyond elytral base. Side swollen and bent ventrally so that lateral border not visible from above (Figs 17, 18). Lateral border of pronotum situated close to posterior margin of prosternum leaving hypomera extremely thin and limiting prosternum to small triangle.
Scutellum triangular, equilateral, small (Fig. 15). Side of elytron with long lobe directed ventrally covering signifi cant part of metepisternite. Epipleura vertical, evenly narrow throughout (Fig. 11). Elytral punctation confused with weak tendency to form rows (Fig. 15). Each puncture of pronotum and elytra with light-colored seta. Tibial apices without long setae and without excavation. Tarsal claws simple and free. Last abdominal ventrite without stridulatory fi le on distal border. Pygidium exposed (Fig. 18). Color. Body entirely black with bluish or bronzish tint, antennal capitulum and mouth parts deep reddish brown.

Cachiporra
Head fl at in lateral view, 1.42 times wider than long in frontal view, completely lacking hairs (except on labrum). Midcranial and frontal sutures absent. Top of frons and bottom of vertex with oval impression. Orbital area swollen and situated above eye level. Internal margin of eye entire, not notched. Distance between eyes 2.64 times as large as transverse diameter of eye. Labrum with three setae on each side placed symmetrically on anterior margin. Antennae extremely capitate with last 4 antennomeres tightly fused to form sphere (Figs 16, 18), inserted slightly above lower eye level with side of antennal socket adjacent to eye margin. Antennomere 1 wide with triangular lobe directed dorsolaterally. Antennomere 2 cylindrical, shorter than wide. Antennomers 3 to 7 dorsoventrally fl at, about as long as antennomere 2, but narrower.
Prothorax. Pronotum apically shallowly sinusoidal, basally sinuate, medially extending posterad beyond elytral base. Each pronotal puncture with short seta. Sides swollen and bent ventrally so that lateral border not visible from above. Lateral border situated close to posterior margin of prosternum leaving hypomera extremely thin and limiting prosternum to small triangle. Intercoxal prosternal process in ventral view slightly longer than wide (length to width ratio 1.26), sides constricted above middle, anterior margin evenly concave with obtuse denticle in middle, posterior margin straight. Intercoxal prosternal process in lateral view nearly straight in middle, abruptly bending posterodorsally. Procoxal cavity open posteriorly.
Wing fully developed (Fig. 19). Radial (RA) sinusoidal, wide, and strongly sclerotized laterally, bending posteriorly. RP connected to posterior arm of radial cell, Abdomen. First visible abdominal ventrite as long (medially) as rest of abdomen. Second visible ventrite narrowest, half as narrow medially as either third and fourth. Th ird and fourth of equal length (Fig. 12). Last abdominal ventrite three times longer than preceding, without stridularoty fi le (device) on distal border. Pygidium exposed.
Kotpresse without dorsal or ventral sclerites with chitinpolster dorsally and ventrally; long lateral fold sclerotized and bent upward and with small denticles (Fig. 22).
Legs. Femora dorsoventrally fl at with anterior and posterior sides nearly parallel to each other. Tibiae slightly curved in ventral view gradually widening apically. All tibial apices with small spur, but without long setae and excavation. Tarsal claws relatively small, simple, and free.
Female genitalia (Figs 20, 21). Paraproct (pleurite of segment IX) narrow. Proctiger (upper layer of tergite IX) widely triangular, with setae on their apical margins, moderately sclerotized and narrow membranous stripe between them. Stylus parallel-sided, at base much narrower than long, separated by distinct border from coxite (apical part of appendage of segment IX). Spermatheca without border between pump and receptacle. Base of spermatheca constricted forming short canal branching into gland and duct. Gland and duct relatively short making no loops. Tignum absent.
Distribution. Brazil, Rio Grande do Norte, Natal.  Pronotum strongly shagreened, evenly covered with sharply impressed small punctures, each bearing a single, small seta. Diameter of punctures four to ten times smaller than distance between them.
Elytral surface strongly shagreened, with numerous wrinkles, some of which short and placed diagonally, some exceptionally long and stretched from base of elytron to and beyond middle. Punctures with tendency to form rows.
Female genitalia. Median side of the lateral sclerotization of tergite IX strongly oblique. Stylus attached slightly anteriorly from apex. Receptacle of spermatheca slightly longer than pump, slightly S-shaped with small bump near base and apically. Apex of spermathecal pump bulbous, wider than receptacle and base of pump.
Material examined. Etymology. Named for the extremely globular antennal club (capitulum). Th e epithet is treated as a noun in apposition.
Among various lamprosomatine genera, Cachiporra is superfi cially most similar in color, size, wing venation, and overall body shape to Oomorphus. Th e pronotum of Cachiporra is considerably diff erent from that of Oomorphus and all other lamprosomatines in having the sides swollen and bent ventrally so that the lateral border is not visible from above. Th e lateral border is therefore located very close to the posterior margin of the prosternum, leaving hypomera extremely thin and limiting the intercoxal prosternal process to the shape of a small triangle. In Oomorphus the sides of the pronotum are not bent ventrally and the hypomera and the prosternum itself occupy most of the ventral side of the lateral part of prothorax. Furthermore, dorsally the pronotum in Cachiporra is basally sinuate and medially extending posterad beyond elytral base (Fig. 15) and side of elytron have an extended lobe directed ventrad nearly concealing all of metepisternite (Fig. 11).
Cachiporra has a number of pleisiomorphies also present in African Neochlamysini. Th ese are absence of a stridulatory device (also absent in Sphaerocharini), entire eyes, completely exposed pygidium, and free and simple claws.
Synapomorphies of Lamprosomatinae (Fig. 29) include the loss of canthus of the eye, character 1 state 1 (1:1); antennomeres 6-8 strongly transverse, more than twice as wide as long, 3:0; triangular scutellum, 8:1; smooth elytra, 12:1; tarsal claws simple and free, 16:1; and have CuA 3+4 and spurt RP distant from each other, 19:1. Of the four tribes, Lamprosomatini has the greatest support with at least four synapomorphies and a number of homoplasious character states (Figs 29-31). Sides of elytra extended in wide relatively short lobe, not concealing much of metepisternite (character 11:1) (Fig. 12) supports the monophyly of Neochlamysini under slow optimization (Fig. 30). Th e transformation of the sides of elytra into a narrow lobe concealing nearly all posterior part of metepisternite (character 11:2) (Fig. 13) is a shared derived feature of Sphaerocharini + Lamprosomatini (Fig. 30) under slow optimization. In Cachiporrini this lobe is wide and long concealing most of middle to posterior part of metepisternite (character 11:0) (Fig. 11); a unique feature of this tribe.
Agricultural University, Kerala, India) for reviewing earlier versions of this manuscript and providing valuable suggestions. We thank Dr. X. Mengual for his generosity and help with software. MLC thanks T. Erwin and the Encyclopedia of Life, Rubenstein fellowship program (National Museum of Natural History, Smithsonian Institution, Washington DC) for funding and support.