A comprehensive guide to the Argentinian case-bearer beetle fauna (Coleoptera, Chrysomelidae, Camptosomata)

Abstract Knowledge of Argentinian Camptosomata has largely remained static for the last 60 years since the last publication by Francisco de Asis Monrós in the 1950’s. One hundred and ninety Camptosomata species (182 Cryptocephalinae and 8 Lamprosomatinae) in 31 genera are recorded herein from Argentina. Illustrated diagnostic keys to the subfamilies, tribes, subtribes and genera of Argentinian Camptosomata, plus species checklists and illustrations for all genera of camptosomatan beetles cited for each political region of Argentina are provided. General notes on the taxonomy and distribution, as well as basic statistics, are also included. This study provides basic information about the Camptosomata fauna in Argentina that will facilitate in the accurate generic-level identification of this group and aid subsequent taxonomic revisions, and phylogenetic, ecological, and biogeographic studies. This information will also facilitate faunistic comparisons between neighboring countries. Two nomenclatural acts are proposed: Temnodachrys (Temnodachrys) argentina (Guérin, 1952), comb. n., and Metallactus bivitticollis (Jacoby, 1907), comb. n. The following are new records for Argentina: Stegnocephala xanthopyga (Suffrian, 1863) and Lamprosoma azureum Germar, 1824. Currently, the most diverse camptosomate tribe in Argentina is Clytrini, with almost twice the number of species of Cryptocephalini. New records for Argentina are predicted.


Introduction
In Argentina there are 956 recorded species of Chrysomelidae (excluding Bruchinae) in 258 genera (Cabrera and Roig-Juñent 1998a). Only two subfamilies of leaf beetles are not represented in Argentina: Donaciinae Kirby and Synetinae LeConte and Horn. Most subtropical species are distributed in the Amazonian and Chacoan domain (Cabrera and Willink 1973). However, current knowledge of Argentinian Chrysomelidae is incomplete. The present paper is the first one in a planned series on the Argentine chrysomelid fauna.
The chrysomelid subfamilies Cryptocephalinae and Lamprosomatinae are collectively known as "Camptosomata" or "case-bearers," due to the peculiar habit of having their eggs, larvae, and pupae living in a fecal protective case (Brown and Funk 2005;Chaboo et al. 2008;Erber 1988, Jolivet andHawkeswood 1995). Adults of case-bearing chrysomelids feed on foliage of a variety of eudicots (Erber 1988), but their larvae often show departures from strict phytophagy. The larvae of some Clytrini and Cryptocephalini live in ant nests, where they feed on other items such as ant droppings and pellets, detritus, leaf litter and even dead insects collected by the ants , and references therein). The larvae of camptosomates can be easily recognized by the behavior of carrying a portable case and the J-shaped body morphology.
Lamprosomatinae includes four tribes (Chamorro and Konstantinov 2011): Cachiporrini (1 genus), Neochlamysini (2 genera), Sphaerocharini (1 genus), and Lamprosomatini (10 genera) (Seeno and Wilcox 1982), totalling 190 described species (Reid 2016). Reid (2016) and Chamorro (2014a), concur on a world estimate of 250 species. In Argentina, the only genus represented is Lamprosoma Kirby. Cryptocephalinae includes ~5300 species, independently calculated by Chamorro, (2014b) and Reid (2016) that are classified into three tribes: Cryptocephalini, Clytrini, and Fulcidacini (until recently treated under the name Chlamisini) as originally proposed by Reid (1995Reid ( , 2000. Members of the subfamily are distributed worldwide, but many tribes have distinct distributions (Erber 1988). Species are phytophagous in the adult stage, primarily leaf and flower feeders. All three tribes of this subfamily have representative genera in Argentina. The main goal of this contribution is to provide an updated systematic framework for Argentinian Camptosomata, treating all of its genera in order to better measure our current knowledge of these groups. This work includes the compilation of former fragmentary literature on the subject.

Type material of Argentinian Camptosomata
Most of the type specimens of Argentinian Camptosomata are deposited in European institutions: The Natural History Museum, London, United Kingdom (BMNH), Hun-garian Natural History Museum, Budapest, Hungary (HNHM), Institut Royal des Sciences Naturelles de Belgique, Brussels, Belgium (KBIN), Museo Regionale di Scienze Naturali di Torino (MRSN), Museum für Naturkunde der Humbolt Universitat, Berlin, Germany (ZMHB), and National Museum, Prague, Czech Republic (NMPC). There are also type specimens in institutions in the United States: Museum of Comparative Zoology Collection, Harvard University, Boston, USA (MCZ), and the National Museum of Natural History, Smithsonian Institution, Washington D.C., USA (USNM). Yet, some type specimens are deposited in Museo de La Plata, La Plata, Argentina (MLPA) (see Cabrera and Roig-Juñent 1998b), Instituto y Fundación Miguel Lillo, Tucumán, Argentina (IMLA) (Aranda et al. 2016), and Museo Argentino de Ciencias Naturales 'Bernardino Rivadavia', Buenos Aires, Argentina (MACN) (Bachmann and Cabrera 2010). Two of the most prominent workers on Argentinian Camptosomata were Francisco de Asis Monrós, whose collection was donated to the Smithsonian Institution (USNM) (Staines 1995), and Manuel Viana, whose collection is now housed in Tucumán and Salta Provinces in Argentina and in Chile. More recently, a few type specimens have been deposited in in the Instituto Argentino de Investigaciones de las Zonas Áridas, Mendoza, Argentina (IADIZA) by Agrain (2013Agrain ( , 2014.

Methods
We studied all catalogs and specialized literature dealing with the genera treated in this contribution. Nomenclature follows previous authors, especially those who made extensive revisions of this group, such as Andrew Moldenke, Francisco Monrós, Jacintho Guérin, and Martin Jacoby. Characters used for identification keys are those used by: Agrain and Roig-Juñent (2011), Chamorro-Lacayo and Konstantinov (2009), Guérin (1943), Karren (1972), Lacordaire and Chapuis (1854), Moldenke (1970Moldenke ( , 1981, Monrós (1949aMonrós ( , 1953a, and Riley et al. (2002). An identification key to the subfamilies, tribes, subtribes, genera, and subgenera of Argentinian Camptosomata was made by compiling and modifying previous publications as indicated in Table 1. Some couplets in our key, derived from keys provided by earlier authors, are based on extreme representatives of a rather continuous spectrum. The latter is due to the fact that many genera, and especially subgenera, require modern revision. Our key is built for the identification of taxa on the territory of Argentina but is useful for the South American continent. The characters given for some widely distributed genera (e.g., Cryptocephalus Geoffroy, Pachybrachis Chevrolat) may not apply to species outside Argentina. Images of dorsal and lateral habiti were taken by different authors as indicated in superscript values: ( 1 ) F. Agrain, ( 2 ) L. Chamorro, ( 3 ) C. Gorretta, N. Cabrera, and ( 4 ) D. Sassi, and edited by F. Agrain. We conducted an exhaustive search of all publications citing Argentinian camptosomates. Here we present a checklist of all currently known camptosomate species from Argentina, their distribution, host plant preferences, juvenile data where available, and known predators. Junior synonyms are provided for each species when applicable. The 24 provinces in Argentina (Fig. 1A) are abbreviated as follows: Buenos Aires (BAS), Antennae short (not surpassing the length of pronotum), serrate; procoxae contiguous ( Fig. 2F)  Head not completely retracted into the prothorax; mandibles in males larger than in females; intercoxal prosternal process strongly and abruptly constricted behind anterior margin; prosternal process more than 3/4 as long as intercoxal prosternal process (Fig. 2H) …Pseudochlamys Lacordaire (Fig. 33)

Cryptocephalinae Gyllenhal, 1813
Adults: Body cylindrical, or rarely as long as wide; in dorsal view parallel-sided with prothorax mostly as wide as combined elytral bases; rarely body rounded; multicolored and patterned, particularly Cryptocephalini, black with red humeri commonly in Clytrini, brown, black, straw-yellow and some with velvet spots in Fulcidacini, glabrous to pubescent, particularly Clytrini. Head retracted into prothorax up to frons or almost completely, with compound eyes completely to barely visible from above. Compound eyes entire, level to strongly protuberant; canthus weak to deep. Antennae 11-segmented, longer than pronotum and filiform in Cryptocephalini (sometimes antennomeres distally dilated and flattened), shorter than pronotum and dentate in Clytrini, clavate in Fulcidacini. Pronotum about 0.75-1.0 times as long as wide, widest basally; sides slightly rounded or sinuate; base slightly narrower or as wide as combined elytral bases. Prosternum in front of coxae usually narrow and shorter than shortest diameter of a single coxal cavity, flat to moderately convex, sometimes produced to conceal mouthparts. Prosternal process complete, usually parallel-sided; notosternal sutures distinct. Procoxae not projecting below prosternum, without concealed lateral extensions; trochantins exposed within coxal cavity. Stridulatory device present on concealed part of mesoscutellum. Tarsi 5-5-5 in both sexes; penultimate tarsomere reduced and antepenultimate bilobed, all usually wider in males; tarsomere III densely clothed beneath with adhesive microtrichia; pretarsal claws simple to deeply bifid. Abdomen with five free ventrites and six tergites. Ventrite I more than twice as long as II, usually longer than ventrites II-IV combined, without postcoxal lines; intercoxal process narrowly rounded to almost truncate. Functional spiracles present on tergites I-VI. Tergite VI forming strongly pigmented pygidium, always exposed; anterior edge of sternite VIII in male without median strut. Ventrite V (=sternite VII) in females with variably-sized apical fovea. Males with segment IX membranous and spiculum gastrale Y-shaped. Aedeagus of cucujiform type; tegmen Y-shaped; struts (remnants of tergite IX) either present or absent; penis flattened to rounded, slightly to strongly curved apically; apically and/or laterally usually with tufts of setae. Sternite VIII in female lacking spiculum ventrale. Ovipositor short, rigid and oval with distinct proctigeral, paraproctal, and coxital baculi; paraprocts deltoid, slightly shorter than undivided coxites, sclerotized or less pigmented proximally, flattened, digitate lobes of variable form, apically setose; styli absent. Spermatheca strongly to moderately sclerotized, variably shaped, usually J-, C-, or S-shaped. Rectal sclerites (rectal apparatus) present in female. Larvae: J-shaped, generally protected by a case. According to Reid (1990Reid ( , 1995, Agrain and Marvaldi (2009) and Chamorro (2014b), the following features characterize the subfamily Cryptocephalinae in the broad sense (i.e., including Clytrini, Cryptocephalini and Fulcidacini), and are probably synapomorphies of cryptocephalines, by outgroup comparison with other chrysomeloids and weevils (Reid 1995(Reid , 2000: body J-shaped; frons, clypeus, and labrum fused; six stemmata, clustered 4 + 2; spiracles uniforous with reticulate peritreme; egg bursters on TII and TIII and associated with a long and a short seta. Lamprosomatinae show a number of larval features in common with the cryptocephalines, being the body J-shaped among the most obvious (and related with their habit of carrying a case), as well as the fusion of frons, clypeus and labrum. Yet, unlike the cryptocephaline larvae, those of Lamprosomatinae have bicameral spiracles with peritreme simple, and five stemmata grouped 2 + 3. The maxillary palp 3-segmented plus the palpiger, as present in both groups, is likely a plesiomorphy, and although both subfamilies have egg-bursters confined to the meso-and metathorax, those in Lamprosomatinae lack the short ventral seta (Agrain and Marvaldi 2009, and references therein). Diagnosis. This genus is easily recognized by the presence of strong parallel carinae on the elytra; other diagnostic characters include: frons very narrow; scutellum slanting posterodorsally, distinctly protruding from the plane of elytra; intercoxal prosternal process nearly absent between fore coxae; epipleural margin broadly angled, tip rounded; elytra without pubescence; frons with medial pit, densely and coarsely punctate throughout; and pygidium strongly convex. Distribution. Only two species from Brazil, one present in Argentina, likely to also occur in Paraguay.
Remarks. Agrain and Roig-Juñent (2011), found eight autapomorphies for the genus, among them elytra with strongly marked longitudinal striae constitutes an exclusive synapomorphy to the genus.
Argentinian species checklist. Note. Moldenke (1981), divided Babia into six subgenera based on morphological features, such as the general shape of the body, pronotal margin, frons and antennomere morphology: Babia ( Type species. Babia elongata Guérin, 1945. By monotypy. Diagnosis. This subgenus can be reliably diagnosed by the shape of anterior margin of pronotum, which is arcuate, and covers the entire head in dorsal view. Also, body shape is elongate (length 3x width), cylindrical and flat; frons is flat; lateral margin of prothorax not widely explanate.
Distribution. Brazil and Argentina. Remarks. Moldenke (1981), mentioned the size of this species to be greater than 10 mm, but average size is smaller than 10 mm.
Distribution. This monotypic genus is limited to Paraguay and north and central Argentina.
Remarks. According to Monrós (1944) this species has always been collected in extremely xeric places.

Argentinian species checklist.
Dachrys succincta (Erichson, 1834)   Type species. Dinophthalma ophthalmica Lacordaire, 1848 designated by Monrós (1953a: 143). Diagnosis. Small body size (less than 7 mm). This genus is very similar to Temnodachrys, from which it can be easily separated by the extraordinary development of the eyes, which are protruding and reaching the lateral margins of the head. Also, antennae with antennomere III large, conical; pronotum transverse; elytra without callus.
Pnesthes Lacordaire, 1848 Type species. Pnesthes ligata Lacordaire designated by Monrós (1953a: 150). Diagnosis. The most particular character to diagnose this genus is the shape of the head, which is anteriorly prolonged, strongly tapering and triangular. Other diagnostic characters are: elongate body, shiny and glabrous; eyes moderately salient; pronotal base lobate; scutellum long and,triangular. Distribution. Two species from Brazil, one of these with a subspecies in Northeastern Argentina which was separated from the typical form by Monrós (1953a) on the basis of its smaller size and distinct punctuation.
Pnesthes instabilis minuta Monrós, 1953a (MNS, SFE). Type species. Stereoma clitellata Lacordaire, designated by Monrós (1953a): 215. Diagnosis. Sexually dimorphic, with males having enlarged forelegs; head completely concealed within prothorax; mesosternum broad; tarsal segments very transverse, tarsomere III cleft 1 / 2 length to receive IV; tarsomere IV notoriously short and thick; frons with prominent transverse sulcation; lateral margin of pronotum broadly explanate, hind angles broadly rounded. This genus is closely related to Urodera, from which it can be separated by the conspicuous development of the legs, since the latter is much larger in males and females compared to Urodera.
Distribution. Seven species and four subspecies are known from Argentina, another 10 species are known from Meridional America (southern part of South America).
Note. Monrós (1953b) divided this diverse genus (more than 60 species) into two subgenera based on the presence of a deep transverse sulcus in the interocular region.     (Monrós, 1953a).
Remarks. Moldenke (1981) subdivided this subgenus into two groups. Argentinian species belong to type II group, which are characterized by having protibiae twice carinate on posterolateral surface; and antennomere IV 1 / 3 -3 / 4 times width of V.
Diagnosis. Scutellum length 1.5x or more than length of posterior lobe of pronotum; frons of male with deep medial depression; dorsal region of aedeagus with very prominent row of setae, no cleft, ventral lobe absent, apex of aedeagus extraordinarily truncate.  (Olivier, 1791), designated by Monrós (1953b: 46). Diagnosis. This genus has several diagnostic characters that clearly separate it from all other Neotropical Clytrini: scutellum inclined posterodorsally, distinctly protruding from the plane of elytra; intercoxal prosternal process nearly absent between fore coxae; epipleural margin broadly angled, tip rounded; elytra without pubescence; frons with medial pit, densely and coarsely punctate throughout; pygidium strongly convex; pronotum with lateral margins sulcate to receive antennae in repose; dorsum brilliant metallic.

Subtribe Megalostomina Chapuis, 1874
Major classification changes in Megalostomina were implemented based on the development of sexual dimorphic characters, especially as they relate to head modifications in males (Agrain and Roig-Juñent 2011). The monophyly of the subtribe is well supported by a set of synapomorphies, including external morphology and genitalia (Agrain and Roig-Juñent 2011). Type species. Coscinoptera desmiphora Lacordaire, 1848, designated by Monrós (1953a: 114). Diagnosis. This genus can be separated from Euryscopa by the lack of bilobed lacinia and the elytra with confused punctation, in some cases exceedingly coarsely and deeply punctate. Other useful diagnostic characters are: head moderately prominent, covered with dense fine punctation and silky pubescence; male head as long as wide; eyes round and salient; prothorax transverse, pronotal disc as high as long; scutellum often coarsely punctate and always with dense white pubescent; elytra either metallic unicolored and glabrous or black; ventrites usually covered with exceedingly dense white pubescence; female anal pit normally small and only moderately depressed.
Distribution. USA to Argentina. Remarks. As for other groups within Clytrini, it is in need of modern taxonomic revision. Several species groups have been proposed, but their monophyly has not yet been tested. Monrós (1953a), split this genus into two informal species groups, mainly based on sexual dimorphism evident in male heads. Moldenke (1970) proposed six informal species groups. Subsequently, Moldenke (1981) preserved only three of his earlier groups and transferred some species to two new genera (Coleorozena and Coleothorpa). More recently, Agrain and Roig-Juñent (2011), recovered a monophyletic clade (sister to Megalostomis), containing the type species of Coscinoptera, Coleorozena, and Coleothorpa. This clade is supported by two synapomorphies: male head as long as wide, and pronotal disc as high as long. Consequently, the latter two genera were synonymized with Coscinoptera. Some North American species are found in the nests of ant genera Camponotus Mayr and Formica Linnaeus. Moldenke (1981)   Diagnosis. Among the species of Megalostomis, several morphological differences exist and the head and thorax are highly variable, therefore, the most useful morphological characters are: presence of a carina in the inter-ocular area, development of anterior teeth on the mandibles, clypeus sculpture, and the degree of retraction of the head inside the prothorax. The thorax may have strong constrictions, which are often present in those species showing great development of the head and mouthparts. The elytra are also variable; the most distinctive characters are the coloration pattern and the ordering of the elytral punctation. Although also variable, the abdomen and legs are not especially useful for the recognition of species groups. The pygidium may possess distinct sculpture patterns, which are useful to diagnose among species.
Distribution. Megalostomis distribution includes North, Central and South America, especially diverse in xeric temperate or subtropical zones.

Tribe Cryptocephalini Gyllenhal, 1813
The most common characters to differentiate this tribe are the procoxae globose, distinctly separated by intercoxal prosternal process. In males of many species of Cryptocephalus (Cryptocephalina) and Griburius (Pachybrachina) the dorsal lobes of the eyes are strongly converging towards the median line and may come into contact with each other. Phylogenetic significance (if any) of this trait is unclear. The antennae are long and filiform in most genera, often reaching the humeral callus or further, although there are exceptions (eg. clavate in Fulcidacini).

Subtribe Cryptocephalina Gyllenhal, 1813
The most distinctive character is the crenulate, not margined, base of pronotum. Some characters present variation, such as the tarsal claws which may be simple or appendiculate, or antennae, which may be short and clavate to subserrate. Diagnosis. Anteriorly flat head, deeply inserted into the prothorax; eyes reniform; leading edge of prothorax laterally straight; denticles present on posterior margin of pronotum; thorax closely fitted to base of elytra (thus sometimes concealing denticles); anterior margin of intercoxal prosternal process uniformly concave or with medial flange; intercoxal width equal to or greater than width of coxal cavity; ventrite I of male without spines. Rectal apparatus bearing one ventral and two dorsal sclerites.
Distribution. Worldwide, with over 1700 species (Chamorro 2014b), with nine species cited for Argentina.
Remarks. Although a complex subgeneric classification does exist for Palearctic species (Schöller 2002), new world species including Argentinian, have not yet been assigned to subgenera.

Subtribe Monachulina Leng, 1920
The members of this subtribe have the intercoxal prosternal process noticeably wider than long; tarsal claws appendiculate; antennae are usually short (rarely longer than base of pronotum) and antennomeres expanded laterally.  (Fabricius)], designated by Balsbaugh (1966: 660). Diagnosis. Lexiphanes may be most commonly confused with Stegnocephala and less so with Cryptocephalus. Both genera in Monachulina have shorter antennae (rarely surpassing half of entire body length) with antennomeres anteriorly expanded (less so in Lexiphanes). Also, the intercoxal prosternal process is wide and bilobed with small lateral projections and the anterior margin of intercoxal prosternal process uniformly concave (Chamorro-Lacayo and Konstantinov 2004). Lexiphanes can be distinguished from Stegnocephala by the more uniform rounded shape of the pronotum, which lacks basolateral depressions. The prothoracic anterior opening in Lexiphanes has a circumference, best viewed anteriorly, with the dorsal and ventral margins on the similar vertical plane (in lateral view). In general, Stegnocephala is larger, more robust, and colorful than Lexiphanes.
Distribution. This genus is restricted to the New World, from México to Argentina with over 100 species. 11 of which are present in Argentina.
Remarks. Balsbaugh (1966) revised the North American species of this genus. The limits of the subtribe, genera, and species need revision. Information is lacking for Central and South American species that are known only from their original descriptions in the 19 th century. The presence of denticles on the posterior margin of pronotum is shared with Cryptocephalina, therefore Monachulina may not be a natural group, and may be a synonym of Cryptocephalina. This hypothesis remains to be tested.
Distribution. From Costa Rica to Argentina, mainly in tropical regions. Remarks. Weise (1921) disagreed with the separation of this genus from Cryptocephalus. White (1968), interpreted Weise's comment as the synonymyzation of Stegnocephala with Cryptocephalus. Since Weise (1921) only provided morphological differences of Cryptocephalus perplexus Suffrian, which is not the type species of the genus, we still consider Stegnocephala as a valid genus. Chamorro is currently revising the genus.

Subtribe Pachybrachina Chapuis, 1874
The following characters (when combined) can help with the identification of its members (Chamorro 2013): Presence of tibial spurs (absent in Mylassa, Ambrotodes, and Griburius s. str.); lack of denticles on the posterior margin of the pronotum (i.e. not crenulate); base of pronotum margined and bilobed sinuate (except in Mylassa and less or differently margined in Ambrotodes); coarsely punctate dorsally and ventrally including hypomeron (except Sternoglossus, and Mylassa); confused elytral punctures (except Mylassa; less orderly in Griburius, Metallactus); intercoxal prosternal process lobed (bilobed in other groups) and posterior margin produced caudad (less so in Pachybrachis; eyes visible from above (not visible from above in Mylassa and Ambrotodes; bulging, particularly in Ambrotodes, and Mylassa, in all other genera the dorsal section of the eye is generally larger than the ventral part as separated by the well developed canthus (canthus weak in Ambrotodes, and Mylassa. This subtribe is currently being revised by Davide Sassi.

Argentinian species checklist.
Griburius bilineolatus (Suffrian, 1866)  Diagnosis. Metallactus includes species that lack a deeply excised lateral edge of the elytra, additionally, the following characters may be useful to segregate species into this genus: posterior margin of intercoxal prosternal process gradually narrowing, pointed; abdomen not exposed; elytral length greater than 2× length of pronotum (Chamorro 2013).
Remarks. This genus has not been revised since its original description by Suffrian (1866) and its relationship with related genera is presently unclear (Schöller 2003, Sassi 2015. Furthermore, Jacoby (1907) indicated Metallactus and Griburius to be very problematic to define, and a lot of species can not fit well in either genera. However, a study with a new diagnosis of the genus Metallactus, based on a new set of effective morphological characters is in progress (Sassi, in prep.).
Argentinian species checklist. Diagnosis. This genus can be easily distinguished from all others in the area by the presence of pubescence on its body and by the presence of a basal thoracic lobe with raised, thickened apex. Furthermore, it has nearly entire eyes and the rectal apparatus bears two ventral and three dorsal sclerites, with the shape of the dorsal central plate band-like (very narrow) (Reid 1990;Schöller 2008).
Distribution. This genus has eight species described form Southern Chile and Argentina, and some new species awaiting description. Species are found between 30°S and 42°S and are associated with sclerophyllous shrubs (Jerez and Briones 2010). Remarks. This genus was considered a synonym of Cryptocephalus by several authors, however several studies support its validity and it is hypothesized to be included in Pachybrachina (Baly 1877b;Jakobson 1924;Monrós 1949a, Schöller 2008Jerez and Briones 2010) or in its own subtribe (Reid 1990;Chamorro and Konstantinov, unpublished data).

Aulacochlamys Monrós, 1951c
Diagnosis. The most salient feature of this genus is the presence medially on the pronotum of six elevated distinct, small, sharp, longitudinal carinae, which converge medially near the posterior margin, reminiscent of a fan. These are small beetles (less than 3 mm length), cylindrical; with antennae serrated beyond antennomere V. antennomeres III-V slightly widened, but not dilated distally; pronotal base opposite mesoscutellum (posterior pronotal lobe) with or without notch; intercoxal prosternal process gradually narrowing posteriorly, broadening before apex; metascutellum concealed by elytra; elytral suture completely serrate, although serration may be weak near scutellum, elytral tubercles well developed. Tibiae slightly curved, cylindrical. Aulacochlamys can easily be distinguished from Chlamisus Rafinesque by the presence of the six longitudinal carinae on its pronotum.
Remarks. Gressitt and Kimoto (1961) synonymized this genus with Chlamisus, yet, this decision has been ignored and is considered to be a valid genus (Karren 1966, 1972; Seeno and Wilcox 1982; Riley et al., 2003). The relationship among Fulcidacini genera remains to be studied.
Argentinian species checklist.  Diagnosis. This genus includes some of the larger and more charismatic species in the group (6.5-7.2 mm length). Body subquadrate and metallic, antenna serrate beyond antennomere III; the head with a longitudinally impressed vertex; elytral tubercles pronounced; posterior pronotal lobe with an acute notch; sutural serration of elytra well-developed beyond the middle of suture towards apex; ventrite I with lateral tubercles; fore-and midtibial apices with spine; tarsal claws simple. According to Chamorro-Lacayo and Konstantinov (2009), Fulcidax can be distinguished from all other genera of the tribe by the longitudinally impressed vertex of the head, simple tarsal claws, large body size, and usually bright metallic coloration.
Distribution. From Mexico to Argentina, with seven species.
Remarks. This is a small genus with only seven described species (Monrós 1951c (Bokermann 1963). Fig. 32 Melittochlamys Monrós, 1948a: 192;Fiebrig 1910 Diagnosis. Melittochlamys can be separated from all other genera by the nearly rectangular prosternal process; since the process is more or less triangular in all other genera of warty leaf beetles. Intermediate size (length 3.60-5.20 mm); body shape subglobular; antenna serrate beyond antennomere III, antennomere III slightly dilated distally; pronotum without median elevation, relatively smooth; sutural serration of elytra absent or weakly developed; elytra without well developed tubercles; appendiculate tarsal claws.

Melittochlamys Monrós, 1948a
Distribution. The genus include 13 Neotropical species (Chamorro-Lacayo and Konstantinov 2009 Diagnosis. Pseudochlamys can be distinguished from all other genera in the tribe by: head not completely retracted into prothorax; mandibles enlarged in males (sexual dimorphism); intercoxal prosternal process strongly and abruptly constricted beyond anterior margin; and prosternal process more than ¾ as long as intercoxal prosternal process. These beetles are small sized (length 3.45-4.72 mm), cylindrical; body usually yellowish; canthus of eye as yellow as rest of frons; pronotum and elytra glabrous; head not completely retracted into prothorax; mandibles enlarged in males; antenna serrate beyond antennomere III, antennomere II slightly widened, globose, antennomere V as large as VI; posterior pronotal lobe with well differentiated notch; intercoxal prosternal process strongly and abruptly constricted beyond anterior margin; sutural serration of elytra complete; elytral tubercles poorly developed; tarsal claws bifid or appendiculate. Distribution. This genus contains only five species, distributed in North, Central, and South America (Chamorro-Lacayo and Konstantinov 2009;Karren 1972).

LAMPROSOMATINAE LACORDAIRE, 1848
Adults: Body compact, strongly convex; head inserted into prothorax (not visible from above). Pronotum convex tightly appressed to elytral base; antennal groove present on each side of prosternal process. Elytra covering pygidium. Larva differs from Cryptocephalinae as pointed out in previous section.

Tribe Lamprosomatini Lacordaire, 1848
This tribe is composed of 10 genera (Seeno and Wilcox 1982) and 250 species (Chamorro 2014a). Four genera occur in the Neotropical region (Chamorro 2014a): Lychnophaes Lacordaire, Dorisina Monrós, Lamprosoma Kirby, and Lamprosomoides Monrós. It is the only Lamprosomatine tribe represented in Argentina where the fauna comprises 1 genus, Lamprosoma, and 8 species. Lamprosoma is characterized by the presence of a file on distal margin of last ventrite; last ventrite not excised in shape of arc; pygidium completely covered by elytra; scutellum acutely triangular (small to very small); elytral punctuation arranged in regular rows or with a tendency to form such rows. Diagnosis. body length about 4.5 mm; tarsal claws appendiculate with broad tooth; antenna short, antennomere VIII nearly as wide as VII or IX. Metallic coloration (some species multicolored), head not visible from above, clypeus excavate. According to Monrós (1956b) it can be differentiated from other Neotropical genera by having appendiculate claws at 180º angle, while Dorisina and Lychnophaes have simple claws at a more obtuse angle.

Discussion and conclusions
This is the first comprehensive synthesis of Argentinian Camptosomata. This study may prove useful also for countries bordering Argentina. Similar contributions indicated the diversity of Camptosomata in other Neotropical countries as follows: Maes (1998) recorded 19 genera and 46 species for Nicaragua, Chaboo and Schöller (2016) accounted for 14 genera and 43 species for Peru; and in Brazil, 723 species, 26 subspecies in 37 genera of Cryptocephalinae (Sekerka et al. 2015) and 62 species in 5 genera of Lamprosomatinae (Sekerka 2017) were recorded.

Species richness and distribution patterns
Historically, Argentina has been divided in two main regions: Andean and Neotropical (Morrone, 2014). As depicted in the distribution pattern of Camptosomata tribes and subtribes by province ( Fig. 35A-D), tribes are mostly distributed in the Neotropical region, while few species reach the Andean region or are found below 40º S latitude. Based on the map of species richness by province (Fig. 36) higher richness (up to 80 species) roughly coincides with the line dividing the Neotropical and Andean regions (Figs 1, 37). Poor data notwithstanding, this pattern fits at the latidudinal diversity gra-    dients hypothesis with greater species richness at tropical latitudes (Hillebrand 2004). Most of the central and northern provinces (e.g. CHA, COR, CTS, FOR, MNS, SAL, SEO, TUC) are presented on the left side of Figure 37, while most of southern provinces (CHT, CHU, NQN, SCZ, STZ, and TFO) appear on the right side, with few exception, for example the lack of information for SJN, ERS, or SLS.
Within Clytrini (Fig. 35A), Arateina is present in the northeastern provinces (FOR, MNS, SEO), while Ischiopachina is distributed throughout most of northeastern Argentina. Megalostomina is present from northern Argentina to the central region (as far as MZA, LPA, and BAS). Babiina covers this same region, yet it reaches the southern provinces (NQN, and RNO). Clytrini has not been reported for the southern provinces beyond Rio Negro.
Cryptocephalini, on the other hand, is putatively mostly absent from the Northwestern provinces of Argentina. The presence of this tribe in Tucumán might indicate a more widespread distribution. Sampling bias and poor inventory may explain the absence of Fulcidacini in central and western regions of Argentina. The subtribes of Cryptocephalini (Fig. 35B) show a more widespread distribution for Cryptocephalina and Pachybrachina, while Monachulina are mostly recorded from Northeastern Argentina. Finally, Lamprosomatinae seems restricted to the Northern provinces, its absence in Formosa seems artificial, so presence of this subfamily surely will expand with more collecting in this region. According to current information, most species are distributed in the Neotropical provinces, especially: Araucaria forest, Chacoan, Monte, Pampean, Parana Forest, and Prepuna.

Current taxonomic knowledge, basic statistics and future research
A total of 190 species (182 Cryptocephalinae + 8 Lamprosomatinae) of Camptosomata are currently known from Argentina. The most diverse group of Camptosomata in Argentina is Clytrini (Fig. 38). However, Clytrini is also, by far, the most studied group in Argentina due to the efforts of Monrós in the 1950's. The patchy distribution at administrative division levels clearly indicates the need for specimen identification and incorporation of museum specimens into databases, as well as collection of new specimens. The latter will permit the application of ecological modelling and biogeographic studies of the group that will provide a more complete picture of the biogeographic history and ecological tolerance ranges, as well as help guide conservation policies for the group. The current estimate of endemic species in Argentina is uncertain, and its calculation based on extant information would be inaccurate, especially without a complete species checklist of bordering countries (i.e. Bolivia, Brazil, Chile, Paraguay, and Uruguay). When comparing the timelines in Fig. 39 with the graphic indicating species richness by genus (Fig. 40), it becomes clear that (except for Megalostomis, recently revised by Agrain (2013), several of the most diverse genera have not been revised in over 100 years. Many species are only known from their original descriptions in the mid 19th or mid 20 th century (Fig. 39). In many cases, the type specimens were not illustrated. This has resulted in long series of unidentified specimens housed in public and private collections awaiting the study of name bearing types.
Our synthesis here is a necessary step towards further comprehensive study of Argentinian Camptosomata that will facilitate field work, assist in determination of unidentified material housed in South American collections, creation of illustrated of keys to the species level, and with identified specimens in hand achieve databasing of museum specimens. These elementary tasks are prerequisite to modern taxonomic revisions and evolutionary studies.