Taxonomic review of Cratocerus Dejean, 1829 (Coleoptera, Carabidae) with the description of six new species

Abstract A diagnosis of the South and Central American genus Cratocerus Dejean (Coleoptera: Carabidae) and a key to all species is provided. Eight species are recognized including six species that are newly described: Cratocerus sinesetosus sp. n. from French Guiana and Peru; Cratocerus multisetosus sp. n. from Costa Rica and Panama; Cratocerus tanyae sp. n. from Costa Rica, Guatemala, and Mexico; Cratocerus indupalmensis sp. n. a species widely distributed throughout Central and South America; Cratocerus kavanaughi sp. n. from French Guiana and Peru; and Cratocerus culpepperi sp. n. from Peru. A lectotype for Cratocerus sulcatus Chaudoir is designated. Habitus images are provided along with illustrations and images of male genitalia, female genitalia, and diagnostic morphological characters.


Introduction
The genus Cratocerus (Coleoptera: Carabidae) was originally described by Dejean (1829) based on two specimens collected from Brazil. Dejean described these as Cratocerus monilicornis and placed the genus within his first division of the Carabidae characterized by moniliform antennae. This first division included two additional genera, Somoplatus Dejean and Daptus Fischer von Waldheim, Cratocerus was separated from these based on the oval shape of the second labial palpomere. Chaudoir (1852) described an additional species of the genus, Cratocerus sulcatus from specimens collected in Mexico. Lacordaire (1854) placed Cratocerus in his group Cratocérides, which included the genera of Dejean's, first division along with Cyclosomus Latreille, Pachytrachelus Chaudoir, Microderes Faldermann, Geopinus LeConte, Batoscelis Dejean, Agonoderus Dejean, Brachidius Chaudoir, Macracanthus Chaudoir, Euryderus LeConte (as Nothopus LeConte), Amblygnathus Dejean, and Polpolchila Solier (as Melanotus Dejean). Murray (1858) placed this grouping at the rank of family, Cratoceridae, and included the newly erected African genus Diatypus Murray (currently considered a subgenus within Notiobia Perty). Chaudoir (1872) later dismantled this grouping and kept only Cratocerus, Brachidius, and Catapiesis Solier (as Basoleia Westwood) within the Cratocérides. Though this restricted Cratocérides was ignored by Chapuis (1876), Bertkau (1873) and Horn (1881) agreed with Chaudoir's, restructuring and recognized the same grouping as Tribe XXX-VIII, the Cratocerini.
Bates (1882) separated out Catapiesis along with Homalomorpha Brulle as their own subfamily, the Catapiesinae, based on the truncate elytra of the species, which left Cratocerus and Brachidius to be grouped together as their own subfamily, the Cratocerinae. Sloane (1923) did not adopt the classification proposed by Bates, but he was not able to examine specimens of Cratocerus during his studies and instead based the tribal characters on Catapiesis exemplars. Csiki (1929) and Blackwelder (1944) kept the constitution of Bates' subfamilies the same, but regarded these as subtribes within Pterostichini-Catapiesi and Cratoceri. Reichardt (1973) removed the Catapiesi from the Pterostichini, placing Catapiesis and Homalomorpha as their own tribe, the Catapiesini. Cratocerus therefore became a monogeneric subtribe, the Cratocerina, within the Pterostichini (Whitehead and Ball 1974, Reichardt 1977, Straneo 1979. In the checklist of Lorenz (2005), the tribe Cratocerini is considered to be within the subfamily Pterostichinae and is composed of the two subtribes Catapiesina (Catapiesis and Homalomorpha) and Cratocerina s. str. (Cratocerus, Brachidius, and Oxyglychus Straneo). Bouchard et al. (2011) alternatively placed the tribes Cratocerini and Catapiesini within the subfamily Harpalinae.
Very little is known regarding the natural history of either the larval or adult stages of any Cratocerus species. Emden (1942) described a larva of Cratocerus, which was found in a rotting stump of a banana tree in Costa Rica, and allied this larva with those he had seen of the African genus Caelostomus MacLeay. Label data of adult specimens indicate that they are often collected underneath decaying tree bark.

Materials and methods
A Leica MZ12.5 stereomicroscope was used to examine 185 adult specimens during this study. Length and ratio measurements were obtained using a calibrated ocular micrometer. When available, ten specimens were measured with at least one from each locality for each measurement to encompass the range of variability. When less than ten were available, measurements for all specimens were taken. Measurements listed include apparent body length (ABL), which was measured from the apex of the labrum to the apex of the elytra; total width (TW), which was measured across the widest point of the elytra; head width (HW) measured across the supraorbital ridges; head length (HL) measured from apex of labrum to base of the head; pronotal width (PW) taken across the widest point of the pronotum, usually anterad to center; pronotal length (PL), measured at pronotal midline from apex to base; and elytral length (EL) measured from humeri to elytral apex.
Habitus images were taken with a BK Lab Imaging system (Visionary Digital) and montaged in Helicon Focus 5.3. At least one male and one female specimen were dissected from each collection locality. Male dissections were performed by first using a hooked insect pin to extract the terminalia, which were then placed into a warm 10% KOH solution for 15-20 minutes to clear surrounding tissue. Dissections were then neutralized in 10% acetic acid and washed in water. For female specimens, the entire abdomen was removed, softened, and subsequently cleared in warm 10% KOH for 20-25 minutes. The genitalia were then removed and placed in chlorazol black for 5-10 minutes in order to stain membranous structures. Line drawings were made using a camera lucida and then digitally inked in Adobe Illustrator. Scanning electron micrographs were obtained at the California Academy of Sciences using a Leo 1450VP. Specimens were air dried and coated with gold/palladium using a Denton Vacuum Desk-II prior to imaging. Maps were created using the Cartographer package version 1.31 in Mesquite version 2.75 (build 566) (D. R. W. P. Maddison and Maddison 2011) using portions of the World, shaded relief and colored height base image from NASA (NASA/JPL/NGA 2004), which was modified for color contrast and cropped to fit.
Verbatim label data for primary type material are listed for each species. A slash (/) indicates separation of lines within one label and a double slash (//) indicates different labels for the specimen. All specimens evaluated in this study were determined to species and bear an identification label. Specimens were borrowed from and will be deposited in the following institutions: American Museum of Natural History, New York, NY (AMNH); Natural History Museum, London, UK (BMNH); Carnegie Museum of Natural History, Pittsburgh, PA (CMNH); Canadian National Collections of Insects, Ottawa, Canada (CNCI); Cornell University Insect Collection, Cornell, NY (CUIC); Museum of Comparative Zoology, Essig Museum of Entomology, Berkeley, CA (EMEC); Harvard University, Cambridge, MA (MCZC); Museo Civico di Storia Naturale, Milan, Italy (MSNM); Muséum National d'Histoire Naturelle, Paris, France (MNHN); and the National Museum of Natural History, Washington, DC (NMNH). All specimen data have been entered into the Essig Museum of Entomology Collection (EMEC) database and records can be accessed online using the EMEC numbers listed for each specimen (http://essigdb.berkeley.edu/query_specimens.html).
The Phylogenetic Species concept sensu Wheeler and Platnick (2000) is used in this study where species are the smallest aggregation of specimens diagnosable by a unique set of character states.
Distribution. The genus is distributed (Fig. 13) from southern Mexico throughout Central America, and into the South American countries of Colombia, Ecuador, Peru, French Guiana, Brazil, and Argentina.
Distribution. This species is geographically distributed in Brazil and northeastern Argentina (Fig. 13). According to Csiki 1929 andBlackwelder 1944, C. monilicornis has also been recorded from Venezuela, but specimens from this locality were not examined during this study.
Additional literature. Dejean  Diagnosis. This species is most easily confused with Cratocerus sinesetosus and Cratocerus multisetosus, but is distinguished by the one pair of pronotal apicolateral setae whereas C. sinesetosus has no setae at this location and C. multisetosus has two or three pairs of setae at this location.
Distribution. Figure 13. The lectotype specimen (here designated) for this species is from Mexico, with the type locality having no further restriction at this time. Only two additional specimens were identified as this species --one from Peru and one from Brazil. These deviate from the type in having slightly less prominent elytral intervals and in the Brazilian specimen, which was smaller, a broader ninth interval near the bases. However, no decisive differences were found and male genitalia were identical. Without additional specimens to examine from across the range, we have tentatively included all three specimens in C. sulcatus.
Diagnosis. This species is distinguished from other members of Cratocerus by the absence of setae on the apicolateral bead of the pronotum. This species most closely resembles Cratocerus sulcatus and Cratocerus multisetosus in overall body shape and coloration, but is easily separated by the absence of apicolateral pronotal setae, whereas there is one pair of apicolateral setae present in C. sulcatus and two or three pairs present on the pronota of C. multisetosus.
Etymology. The specific epithet refers to the absence of any anterior marginal setae on the pronotum of this species. The name is formed by combining the Latin sine (without) and setosus (setose); adjective.
Distribution. This species is distributed (Fig. 13) throughout French Guiana, Peru, and Ecuador.
Ecology. Specimens have been collected from underneath the bark of rotting trees during the month of February and from flight intercept traps throughout the year. Diagnosis. Distinguishable from similar looking species such as C. sulcatus and C. sinesetosus, by the additional setae on the pronotal margin (Fig. 9d) and moderately convex elytral intervals.
Etymology. The specific epithet refers to the two or three anterior marginal setae on each side of the pronotum found in this species. The name is formed by combining the Latin multi (many) and setosus (setose); adjective.
Distribution. This species is distributed (Fig. 13) throughout Costa Rica and has also been collected in Panama.   Diagnosis. This species most closely resembles Cratocerus indupalmensis and can be distinguished by the smaller size, differently shaped pronotum (Fig. 9e, f), and the differently sized and shaped median lobe of the male genitalia (Fig. 11d, e).
Etymology. This species is named in recognition of Tanya Shahjanian. As an undergraduate student at the University of California, Berkeley, Tanya participated in an insect art and culture project competition and was selected by the panel of judges as the winner with a sculpture piece called "It's an insect world". As a prize this fine species of beetle is named for her.
Distribution. This species is distributed (Fig. 13) from Mexico through the Central American countries of Guatemala and Costa Rica.

Cratocerus indupalmensis
Diagnosis. This species is most easily confused with Cratocerus tanyae and can generally be separated by its slightly larger overall body size and the differently shaped pronotum (Fig. 9e, f). The size and shape of the median lobe of the male genitalia distinctly diagnose these two species (Fig. 11d, e).
Etymology. The specific epithet refers to a series of specimens bearing locality labels specifying "Indupalma". This series represent the specimens that were first recognized as constituting part of this quite variable new species of Cratocerus. Indupalma is treated as an adjective.
Distribution. This widespread species (Fig. 13) has been collected in Belize, Brazil, Colombia, Costa Rica, Ecuador, El Salvador, French Guiana, Guatemala, Mexico, Panama, and Peru. Ecology. This species has been collected under the bark of rotting, fallen trees.   Diagnosis. This species is distinguished from other members of Cratocerus by the strongly curved mandibles, 45 degrees in relation to the mandibular midline and the two basal pronotal fovea. This species is most easily confused with Cratocerus culpepperi as both have the distinctively curved mandibles, a character which does not occur in any other species within Cratocerus. Cratocerus kavanaughi is easily identified by the larger overall body size and the two pronotal basal fovea as opposed to the five found with Cratocerus culpepperi specimens (Fig. 9g, h).
Etymology. The specific epithet, kavanaughi, is a Latinized version (genitive case) of the surname of Dr. David H. Kavanaugh, an entomology curator at the California Academy of Sciences. Dr. Kavanaugh provided numerous resources and support to TLG throughout the duration of this project. This species is named in gratitude of this support.
Distribution. This species is geographically distributed (Fig. 13) throughout French Guiana and Peru.
Ecology. Specimens have been collected in flight intercept traps during the months of November, December, January, February, April, and July and under tree bark in October.   ly thin and filamentous, gradually expanding approximately 1/3 below apex, ended with broad bulb (Fig. 12b).
Etymology. This species is named in recognition of Meghan Culpepper, currently a PhD student of carabid phylogenetics and biogeography who provided endless amounts of support throughout the duration of this project. Though this species is one of the smallest within the genus Cratocerus, the red hue of the integument and  morphological characters mentioned above make it one of the most distinctive. Miss Culpepper is equally unique and we name this species for her.
Distribution. This species is currently only known from Peru (Fig. 13). Ecology. Specimens examined in this study were all collected from insecticidal fogging of suspended dry leaves in the canopy and a tree during the month of June.

Discussion
No detailed study of the characteristics of Cratocerus relative to their possible placement in a tribal scheme has been done. They are clearly placed in Harpalinae based on the shared harpalidian abdominal configuration (Liebherr andWill 1998, Deuve 1993). An association with Catapiesis, Brachidius and Oxyglychus was suggested by Will et al. (2000) given similarities of tergite VIII, whereby the tergite is divided into hemitergites and those further divided into epitergites in a manner unlike lebiomorphs and orthogonines. The tergal configuration in Cratocerus, Catapiesis, Brachidius and Oxyglychus is not equivalent to "tergite turrets" of lebiomorphs and orthogonines (contra Erwin 1984, Erwin 1985, Bousquet 2012, Ober and Maddison 2008. Decyl acetate is an uncommonly produced compound in carabids that was found in the defensive chemicals of the pygidial glands in Catapiesis species  and has also been found in Brachidius (Will and Attygalle unpublished data). Pygidial gland compounds are not known for Cratocerus and Oxyglychus. Preliminary analyses of three independent molecular loci consistently group Cratocerus, Catapiesis, and Brachidius (Will, Kanda and Maddison unpublished data), but no sequence data are available for Oxyglychus. Though preliminary and incomplete, these new findings are consistent with recognition of Cratocerini sensu Lorenz (2005), and the placement of the tribe in Harpalinae remains sedis mutabilis.