I I BULLETIN DE L'INSTITUT ROYAL DES SCIENCES NATURELLES DE BELGIQUE, ENTOMOLOGIE, 59 : 13I-I 44, 1989 BULLETIN VAN HET KONINKLIJK BELGISCH INSTITUUT YOOR NATUURWETENSCHAPPEN, ENTOMOLOGIE, 59: 131-144, 1989 The Calosoma species of the Galapagos archipelago. I. Redescriptions and distribution of the species by Konjev DESENDER and Bart DE DIJN Contribution No. 438 of the Charles Darwin Research Sta­ the taxonomic literature of these beetles from Ga!apago~. tion. It is a great merrit of BASILEWSKY (1968) to have brought basic order in the formerly used nomenclature by recogni­ zing three different species and a lot of synonymies. Summary Moreover, a fourth species from Isla Santa Cruz was des­ cribed as new by that author. Recently we started investiga­ In th is paper the species of the genus Calosoma WEBER, 1801 (Coleoptera, tions on the beetles and spiders of the Galapagos islands Carabidae) from the Galapagos islands are redescribed in detail. Therefore (cfr. BAERT & MAELFAIT, 1986, BAERT et al., 1989 and more than 800 specimens collected during recent expeditions on 14 diffe­ rent is lands or volcanoes of the archipelago have been examined in detail DESENDER et at., 1988, 1989). During three expeditions and moreover measured for a large number of biometric variables. About (1982, 1986 and 1988; BAERT, MAELFAIT & DESENDER) we 1.200 additional specimens were studied but not measured. managed to sample all important islands and volcanoes of Based on single characteristics an unambiguous identification to species the archipelago, including the different volcanoes of !sa­ level is not always possible due to the very hi gh intraspecific variability bela and Fernandina, some of which had, until now, never shown by some of the species. Several characters, used in previous taxono­ mic papers moreover seem to be influenced epigeneticall y or were formerly been prospected for these invertebrates. We were also for­ unprecisely or even erroneously described. Species identification is most tunate to have access to the collections of: (1) the Charles easy by means of a combination of characters, especially those describing Darwin Research Station, (2) the Belgian entomologists N. the size and shape of male genitalia. These characters were not used in LELEUP (1964, identified and Studied by BASILEWSKY, previous taxonomic keys to these Calosoma species. 1968), S. JACQUEMART (1974 expedition) and BAERT & Key-words: Calosoma, taxonomy, distribution. MA ELFAIT (1982 expedition), deposited in the K.B.I.N. at Brussels, (3) H. and I. ScHATZ (1985 and 1987 expeditions, identified) gathered during their ecological investigations Resume of the soil invertebrates of the Galapagos islands. Detailed studies on our abundant Calosoma material show­ Dans cette publication les especes du genre Calosoma WEBER, 1801 (Co­ leoptera, Carabidae) des lies Galapagos sont redecrites en detail. Dans ce ed that a number of hitherto used characters in species but plus de 800 specimens collectionnes recemment au cours d'expeditions recognition were unprecisely or even wrongly described, dans 14 iles ou volcans differents de I'archipel ont ete examines en detail adding to the already existing problems of ambiguous iden­ et mesures pour un grand nombre de variables biometriques. De plus ou tification. We therefore thought it would be of general moins 1.200 specimens fGrent etudies sans biometric. interest to redescribe the known species based on our mate­ Une identification des especes n 'est pas toujours possible a partir de caracteres simples due a Ia variabilite intraspecifique tres large de quelques rial at hand. especes. Plusieurs caracteres, utilises dans des publications anterieures, In this paper the first part of our work is presented, namely semblent egalement etre influences d 'une fac;:on epigenetique ou etaient the detailed redescriptions of the taxa on species rank. This impn!cisement ou meme erronement decrits. L'identification des especes paper also provides a compilation of all known distributio­ est le plus facile a partir d'une combinaison de caractere , spec ialement nal data for the species mentioned. To prevent redundancy ceux qui decrivent Ia tai lle et Ia forme des genitalias males. Jadis, ces and for the matter of clarity we will only mention the caracteres ne fGrent jamais utilises dans des cles de determination pour ces especes de Calosoma. different islands and vegetation belts where species have Mots-clefs : Calosoma, taxinomie, repartition. been found and we refer to a former paper for all detailed data (DESENDER eta/., 1989). The second part of this study will deal with canonical discriminant function analyses in Introduction, material and methods order to identify these species on a multivariate basis. An identification key will be added to that part of publication The genus Calosoma WEBER , 180 I belongs to the relatively (DESENDER & DE DuN , in prep.). At the moment we are most studied beetles of the Gahipagos archipelago. Never­ analyzing in more details our infraspecific data, which theless, until recently, there has been a lot of confusion in pose, as usual with island fauna's, a number of methodo- I I 132 Konjev DESENDER and Bart DE DIJN logical problems in subspecific designations. Moreover, we SYNONYMS AND REFERENCES have not yet obtained type material from one subspecies, which needs to be checked. The results of these analyses Calosoma granatense GEJ-IIN, 1885, p. 59. will be presented in a future paper (DESENDER, in prep.). Calosoma galapagoum HoWARD, 1889, p. 191 (non HoPE). We will only use the genusname Calosoma WEBER, 1801 Calosoma howardi LI NELL, 1898, p. 25 1. in this paper. We have indeed observed that important Ca/osoma galapageium RoESCHKE, 1900, p. 59 (non HoPE). characters in subgeneric (or according to some authors Calosoma howardi : MuTCHLER (1925), p. 223. generic rank) identification in many cases even show Ca/osoma (Ca./listriga) galapageium : BREUNING (1927), p. 200 intraspecific variability not accounted for. Moreover the (non HoPE). extreme splitting of the "family" Carabidae in many diffe­ Ca/osoma howardi: BLAIR (1933), p. 472. rent families and the higher levelling of subgenera to Ca/osoma howardi: MuTCHLER (1938), p. 3. Cas11·ida (Microcalosoma) galapageium : JEANNEL (1940), pp. 93, genera as proposed by JEA NNEL (1940) is not any longer 98, fig. 2 (non HoPE). followed by many Carabid taxonomists. Therefore, at the Ca/osoma howardi: VAN D YKE (1953), pp. 7-9, pl. I, fig. I. time being, we propose only to use the genusname Colo­ Ca/osoma darwinia VAN DYKE, 1953, pp. 10-11 , pl. I, figs. 3, 5. soma WEBER, 1801. As already mentioned there are also Calosoma (Castrida) galapageium: GIDASPOW (1936), pp. 286, a number of problems with subspecific nomenclature of 289, figs. 2, 14-19, 25, 62-74 (non HoPE). the Calosoma species of Galapagos, which will be dealt Calosoma darwinia: LI NSLEY & UsiNGER (1966), p. 141. with in another paper. Calosoma howardi : LI NSLEY & UsiNGER (1966), p. 141. All measurements were made with a stereomicroscope Casll·ida grana tense : BASILEWSKY ( 1968), pp. 189-200. WILD M5 with a calibrated ocular. Standard total length Cas11·ida granatensis : LINSLEY ( I 977), pp. I 9-20. Castrida granatense : FRANZ (1985), pp. 75-76. was defined from the frontal margin of the clypeus until Cas11·ida granatense : MoRET ( 1986), pp. 92-93. the apical margin of the elytra; in addition to biometric size variables, a number of meristic variables (chaetotaxy on different body parts), as well as other discontinuously MATERIAL EXAMINED varying characteristics were also noted. The male genitalia as well as female external reproductive structures (gonapo­ Detailed data and biometrics were gathered from 376 males physe) were prepared in each individual and also measured. and 367 females collected on different altitudes on the Finally dispersal power characteristics were also investiga­ islands Espanola, Floreana, lsabela, Marchena, Pinta, ted : these include a standardized measure of flight wing Pinzon, San Cristobal, Santa Cruz, Santa Fe, Santiago, development (% max allometry, cfr. DESENDER et al., Seymour; in addition about 1.160 other specimens were 1986), which is based on wing length x wing width and identified without detailed biometrics and dissections. corrects for absolute body size differences, furthermore a measure of the functional state of indirect flight muscula­ ture and finally characteristics describing the size and pun­ DIAGNOSIS tuation of the metepisternum. We will now describe the different species : in each case Extremely variable species, only identified with certainty we will (1 °) compile all known synonymies and references, by means of a combination of characters, especially male (2°) treat the material examined, (3°) diagnose the species genitalia which are slender and rather narrow at the orifi­ as far as possible, (4°) redescribe them (general size and cium and possess a moderately long penistip (figs. 2-3); shape, head, prothorax, abdomen and elytra, flight wings, externally (fig. 1) distinguished from C. leleuporum by the indirect flight musculature and metapisternum, male geni­ relatively narrower head and apical part of pronotum, from talia, female external reproductive structures, color of inte­ C. linelli by the larger size and relatively longer abdomen gument) and finally (5°) summarize our data on distribu­ and elytra; externally only distinguishable from C. galapa­ tion, habitat choice and zoogeographic affinities. Biometric geium by means of a combination of several characters values in these redescriptions always show mean value (discriminant function analyses, DESENDER & DE DuN, in (minimum - maximum), expressed in mm, unless mentio­ prep.). ned otherwise. DESCRIPTION Results (a) General size and shape : Standard total length : Calosoma granatense GEHIN, 1885 males : 19.20 (13.67-22.67) (n = 376) (Plate I) females: 19.85 (15.84-22.84) (n = 367) Maximal width (elytra) : TYPE males : 8.61 (5.66-10.16) females : 9.03 (7 .00- 11.00) Colombia (1885?, 1 ind., holotype): exact locality un­ Body shape : cfr. fig. 1; abdomen with elytra in the mean known; Museum Hist. Nat.