El estudio de la fauna carroñera desde una perspectiva forense permite conocer el proceso de descomposición de los vertebrados (aún en una sucesión cadavérica antigua) y contribuye con los estudios fafonómicos. En esta investigación, fueron examinados los insectos asociados a restos de lobos marinos de 1290 ± 100 años AP hallados en Puerto Madryn (Argentina). Las especies registradas fueron: Cochliomyia macellaria y Fannia sp. (Diptera), Dermestes maculatus y Necrobia rufipes (Coleoptera) y Tineola cf. biselliella (Lepidoptera). Fue determinado que la sucesión se desarrolló a fines de la primavera o comienzos del verano y los restos estuvieron expuestos al aire abierto por aproximadamente 50 días, cuando la descomposición aparentemente fue interrumpida por fenómenos de remoción en masa que enterraron los restos.The study of a carrion fauna from a forensic perspective provides insight into cadaveric succession during vertebrate decomposition and contributes to documentation of taphonomic processes. The insects associated with sea lion bones of 1290 ± 100 years BP found in Puerto Madryn (Argentina) were examined. The recorded species were: Cochliomyia macellaria and Fannia sp. (Diptera), Dermestes maculatus and Necrobia rufipes (Coleoptera), and Tineola cf. biselliella (Lepidoptera). The succession of insect species occurred at the end of spring or the beginning of summer, on carrion exposed to the open air for approximately 50 days. Decomposition was apparently interrupted by mass wasting that buried the carcasses.Fil: Centeno, Néstor Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Quilmes. Centro de Estudios e Investigación; ArgentinaFil: Serran, Martin Emmanuel. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Quilmes. Centro de Estudios e Investigación; ArgentinaFil: Gomez Otero, Julieta. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico; ArgentinaFil: Weiler, Nilda Ester. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico; Argentin

Centeno, Néstor Daniel

Gomez Otero, Julieta

Serran, Martin Emmanuel

Weiler, Nilda Ester

Entomologica Americana

English

CONICET Digital

AN ANCIENT ASSEMBLAGE OF SCAVENGER INSECTS INPATAGONIA (ARGENTINA)N. CENTENO1, M. SERRÁN1, J. GOMEZ OTERO2 AND N. WEILER21Centro de Estudios e Investigaciones, Universidad Nacional de Quilmes, Sáenz Peña 352, Bernal(B1876BXD), Provincia de Buenos Aires, Argentina. e-mail: ncenteno@unq.edu.ar;cdxtremere@yahoo.com.ar2CENPAT, Boulevard Brown S/Nro (9120), Puerto Madryn (Provincia de Chubut), Argentina.e-mail: julieta@cenpat.edu.ar; weiler@cenpat.edu.arAbstract.—The study of a carrion fauna from a forensic perspective provides insight into cadaveric successionduring vertebrate decomposition and contributes to documentation of taphonomic processes. The insects associatedwith sea lion bones of 1290 6 100 years BP found in Puerto Madryn (Argentina) were examined. The recordedspecies were: Cochliomyia macellaria and Fannia sp. (Diptera), Dermestes maculatus and Necrobia rufipes(Coleoptera), and Tineola cf. biselliella (Lepidoptera). The succession of insect species occurred at the end of springor the beginning of summer, on carrion exposed to the open air for approximately 50 days. Decomposition wasapparently interrupted by mass wasting that buried the carcasses.Key words: carrion fauna, taphonomy, forensic entomology, cadaveric succession, Argentina.Resúmen.—El estudio de la fauna carroñera desde una perspectiva forense permite conocer el proceso dedescomposición de los vertebrados (aún en una sucesión cadavérica antigua) y contribuye con los estudiosfafonómicos. En esta investigación, fueron examinados los insectos asociados a restos de lobos marinos de 1290 6100 14C años AP hallados en Puerto Madryn (Argentina). Las especies registradas fueron: Cochliomyia macellaria yFannia sp. (Diptera), Dermestes maculatus y Necrobia rufipes (Coleoptera) y Tineola cf. biselliella (Lepidoptera). Fuedeterminado que la sucesión se desarrolló a fines de la primavera o comienzos del verano y los restos estuvieronexpuestos al aire abierto por aproximadamente 50 dı́as, cuando la descomposición aparentemente fue interrumpidapor fenómenos de remoción en masa que enterraron los restos.Key words: fauna cadavérica, tafonomı́a, entomologı́a forense, sucesión cadavérica, Argentina.Vertebrate carcass decomposition implies aheterotrophic succession where, throughout rela-tively discrete diverse stages, various arthropodgroups colonize the carrion as a resource forfeeding and breeding (Goff, 1993; Centeno et al.2002). From the succession of the carrion fauna itis possible to obtain information about circum-stances associated with and following the death ofthe animal(s), which is helpful in forensic inves-tigations (Goff 1993; Benecke, 2001).Different body parts of insects and otherarthropods can be preserved unaltered for thou-sands of years [e.g., 24,550 6 600 years BP (Coope,1986; Petrulevicius, 2001)] or can become fossilized.For example, fossilized Diptera of the familyCalliphoridae have been found in association withPleistocene mammals from Argentina, and repre-sent an example of an ancient cadaveric decayassemblage (Petrulevicius, 2001). No fossilizedscavenger insects were found associated withEgyptian or Peruvian mummies dating to severalthousands years B.P. (Panagiotakopulu 2001). Thestudy of assemblages of insects found in arche-ological sites from the Middle Ages providesknowledge about environment utilization, displace-ments, and behavior of ancient populations (Hellq-vist & Lemdahl, 1996; Carrott & Kenward, 2001).The knowledge of cadaver fauna from a specifictime can be helpful in the study of circumstancesassociated with past events such as animal deathand decay, graves, mummies, or other sites ofarchaeological interest. The study of this faunafrom a forensic perspective can contribute informa-tion valuable to reconstructing past events (Pana-giotakopulu, 2004). Our study of carrion insectswas carried out in conjunction with an archaeolog-ical investigation in Patagonia, Argentina.MATERIALS AND METHODSInsect remains were collected from the site of ataphonomic event at the site called ‘‘Sitio Lobos’’,located at Punta Dorado, on the Golfo Nuevocoast, 12 km northeast of Puerto Madryn (SerránEntomologica Americana 115(1):77–80, 2009et al. 2007). This site was found by members ofthe archaeology laboratory of the Centro Nacio-nal Patagónico (Patagonia, Argentina), whodiscovered bones arising within the walls of agully aligned perpendicular to the coast. The boneremains were buried at depths ranging from 40–70 cm, in a continuous layer that extended 13 m,located 44 m inland from the high tide line and1.85 m above present sea level. The bones wereidentified as those of at least 22 individual sealions (Otaria flavescens (Shaw)) of both sexes andvarying ages (i. e., pups, juveniles, subadults andadults). A radiocarbonic age of 1290 6 100 C-14B.P. was reported (Serrán et al 2007). Tapho-nomic analyses indicated a mass mortality eventof the sea lions. No evidence of human activity orcatastrophic event was recognized in the site; thusan acute illness was proposed as the cause ofdeath (Serrán et al., 2007).Remains of several arthropods, some of themwell preserved, were collected in association withthe sea lion bones. Taxonomic analysis of theinsects and their context within the site allowedestablishment of the cadaver-inhabiting nature ofthe fauna. We analyzed the insects from a forensicperspective, trying to determine the incidence ofdifferent processes at the site.The insect remains and the associated sedimentwere transferred to the laboratory where theywere cleaned, using minutens, brushes and otherinstruments in order to prepare them for taxo-nomic determination. Insect remains were storedin the Laboratory of the Centro de Estudios eInvestigaciones at the Universidad Nacional deQuilmes. Table 1 lists the identified species andincludes some details about the life stagesrepresented in the fauna.RESULTS AND DISCUSSIONThe discovery of several puparia of Calliphor-idae containing other calliphorid puparia inside isevidence of more than a single generationalcohort. The larvae of the second generationentered empty puparia from the first generationin order to pupate. Something similar would havehappened with pupae of Fannia sp. which werefound inside Cochliomyia macellaria F. puparia,indicating that at least some of the Fannia arrivedafter the Calliphoridae. This observation isconsistent with results obtained from SantaCatalina (Buenos Aires province, Argentina)where Calliphoridae arrived relatively early, fol-lowed by Fannia sp. during the more advancedstages of decay (Centeno et al., 2002).The Cleridae are represented by Necrobiarufipes De Geer, an omnivorous species that, oncethe succession started, likely came to the carrionin order to feed on dipterous eggs or larvae. It isalso conjectured that this clerid might feed on fatfrom the corpses (Payne & King, 1970). The restof the coleopterous larval exuviae are fromDermestes maculatus De Geer, indicating that thissuccession proceeded to an advanced decay stage,close to skeletonization and/or mummification,where only bony tissue, dried skin and hair arepreserved. This interpretation is reinforced by thepresence of a Lepidopteran cocoon, probably arepresentative of the family Tineidae, and verysimilar to Tineola biselliella Hummel. Larvae ofthis species are known to feed on hair and otherdried tissues (Payne & King, 1969; Oliva, 1997).With respect to the estimation of event season-ality, palaeoclimatic studies indicate that currentweather conditions in the plateau of north Pata-gonia extrandina began about 2500–2000 years BP(Páez 1993; Schäbitz & Liebricht 1998). Thatallows us to infer that at the time of death of thesea lions, climatic conditions in the area weresimilar to the present arid temperate environment.Referring to Calliphoridae seasonality in a tem-perate climate like that NW of Buenos Airesprovince (Centeno et al., 2004), Calliphora macel-Table 1. Species and body parts of arthropod remains from Sitio Lobos.Order Family Species RemainsDiptera Calliphoridae Cochliomyia macellaria F. pupae, empty puparia and puparia containingother puparia or an adultDiptera Fannidae Fannia sp. pupa inside C. macellaria puparium, emptypupariaColeoptera Dermestidae Dermestes maculatus De Geer exuviaCleridae Necrobia rufipes De Geer head, thorax, elytra, abdomenLepidoptera Tineidae Tineola sp. cf. biselliella Hummel cocoon78 ENTOMOLOGICA AMERICANA Vol. 115(1)laria are most abundant during the late spring andearly summer. Thus, the abundance of puparia ofC. macellaria indicates that decomposition wouldhave taken place during the warm season of theyear, probably the end of spring or the beginning ofsummer. The absence here of other Calliphoridaespecies that are common during other seasons ofthe year reinforces this prediction. These results aresupported by thin-section analysis of the pup andadult sea lion teeth, which corroborate the summeras the most probable season of their demise.Geomorphological analyses show that the layercontaining the pinneped bones is composed ofsmall gravel (coming from the palaeocliff) mixedwith coarse sand and small scattered molluscvalves. This indicates that the corpses were buriedby a mass wasting event, possibly due to torrentialrain. Under semiarid climatic conditions with cooltemperatures, severe droughts commonly alter-nate with violent pluviometric episodes that canmove a great amount of detritus. Coronato & DelValle (1993) calculated that the 63% of the hydricerosion that occurred in the northeast of Chubutduring a sixteen month period was due to onlytwo intense pluviometric summer episodes. (seeSerrán et al., 2007 for further information).To calculate the length of time the corpses wereexposed prior to burial, it is important to take intoaccount the development rates of C. macellaria in thelaboratory, which vary between 13 and 14 days attemperatures between 16u C and 29u C (Greenberg,1991). The added time of overlapping generationsextends the estimated duration of exposure some-what. The minimum development time for a C.macellaria larva to reach stage III is estimated to betwo days (under the previously described conditions);at this time, the larva entered into an empty pupariumleft behind by the previous generation in order topupate (Byrd & Butler, 1996). This indicates that thecarcasses were unburied until at least the 10th or 11thday of succession, being able to attract C. macellariaand be colonized with new eggs, from which arose thelarvae that pupated in empty puparia.Cadaveric decomposition studies conducted inBuenos Aires province during the summer showedthat dermestid beetles were captured 10 days afterthe beginning of succession, when remains were inan advanced decomposition stage (Centeno et al.,2002). This span coincides with the estimated timethat the corpses remained exposed based on theremains of C. macellaria. These data allow us toconclude that the first stages of decompositionwould have been reached by at least 10 or 11 dayspost-mortem. Then, the remains were unburieduntil reaching a dry stage (mummification/skele-tonization), providing suitable habitat for beetlessuch as D. maculatus and eventually, sarcopha-gous moths such as T. biselliella. The intervallength of this final stage is hard to estimate,considering that T. biselliella takes almost 40 daysto reach the pupa stage. From this, it can beassumed that approximately 40 days passedfollowing the initial stages of decomposition.The post-mortem interval thus can be estimatedas 50 days, this being the time interval in whichthe cadaveric succession developed before reach-ing a stage of near-skeletonization. Then the sealion carcasses would have been buried by a masswasting episode, possibly due to torrential rain.ACKNOWLEDGMENTWe want to thank for the valuable commentariesof the reviewers of the article. Also we thank for E.Crespo and N. Garcı́a for the section analysis of thepup and adult sea lion teeth. The Lic. Serran have afellowship from CONICET. Dr. Centeno is support-ed by Agencia Nacional de Promoción Cientı́fica yTecnológica and Universidad Nacional de Quilmes.LITERATURE CITEDBenecke, M. 2001. A brief history of forensic entomology.Forensic Science International 120(1–2): 2–14.Byrd, J. H. and J. F. Butler. 1996. Effects ofTemperature on Cochliomyia macellaria (Diptera:Calliphoridae) Development. Journal of MedicalEntomology 33(6): 901–905 (1996).Carrott, J. and H. Kenward. 2001. Species AssociationsAmong Insect Remains from Urban Archaeolog-ical Deposits and their Significance in Recon-structing the Past Human Environment. Journalof Archaeological Science 28: 887–905.Centeno, N., M. Maldonado and A. Oliva. 2002.Seasonal patterns of arthropods occurring onsheltered and unsheltered pig carcasses in BuenosAires province (Argentina). Forensic ScienceInternational 126: 63–70.Centeno, N., D. Almorza and C. Arnillas. 2004. A Studyof Diversity on Calliphoridae (Insecta: Diptera)in Hudson, Argentina. Neotropical Entomology33(3): 387–390.Coope, G. R. 1986. Coleoptera analysis. In: B. E.Berglund (ed.), ‘‘Handbook of Holocene Palaeoe-cology and Palaeohydrology.’’, pp. 703–713.John Wiley and Sons, New York.Coronato, F. and H. Del Valle. 1993. Methodologicalcomparisons in the estimate of fluvial erosion in2009 OLD CADAVERIC FAUNA 79an arid closed basin of north-eastern Patagonia.Journal of Arid Environments 24: 231–239.Goff, M. L. 1993. Estimation of postmortem intervalusing arthropod development and successionalpatterns. Forensic Science Review 5(2): 81–94.Greenberg, B. 1991. Flies as forensic indicators. Journalof Medical Entomology 28(5): 565–577.Hellqvist, M. and G. Lemdahl. 1996. Insect Assemblagesand Local Environment in the Mediaeval Townof Uppsala, Sweden. Journal of ArchaeologicalScience 23: 873–881.Oliva, A. 1997. Insectos de interés forense de BuenosAires (Argentina). Primera lista ilustrada y datosbionómicos. Revista del Museo Argentino deCiencias Naturales ‘‘Bernardino Rivadavia’’.Entomologı́a 7(2): 14–59.Paez, M. 1993. Historia paleoambiental y ocupaciónhumana en el valle de Piedra Parada (Chubut).En Actas de las II Jornadas de Arqueologı́a de laPatagonia, Centro Nacional Patagónico, PuertoMadryn. (electronic version).Panagiotakopulu, E. 2001. New Records for AncientPests: Archaeoentomology in Egypt. Journal ofArchaeological Science 28: 1235–1246.Panagiotakopulu, E. 2004. Dipterous remains andarchaeological interpretation. Journal of Archae-ological Science 31: 1675–1684.Payne, J. A. and E. W. King. 1969. Lepidopteraassociated with pig carrion. Journal of theLepidopterists Society 23(3): 191–195.Payne, J. A. and E. W. King. 1970. Coleopteraassociated with pig carrion. Entomologist’sMonthly Magazine 105: 224–232.Petrulevicius, J. F. 2001. Cenozoic insects from Argen-tina. Proceedings of the First InternationalMeeting on Paleoarthropodology, Special Issueof Acta Geologica Leopoldensia 24(52–53):137–144 ISSN 0101-5303, Editora Unisinos,Ribeirão Preto.Schäbitz, F. and H. Liebricht. 1998. Landscape andclimate development in the south-eastern part ofthe Arid Diagonal during the last 13,000 years.Bamberger Geographische Schriften H 15:371–388.Serran, M., N. Centeno, N. Weiler and J. Gomez Otero.2007. Massive death of pinnipeds 1200 years ago:Taphonomic history of the ‘‘Lobos site’’ (GolfoNuevo, Patagonia, Argentina). Quaternary In-ternational (2007). doi: 10.1016/j.quaint.2006.12.001Received and accepted February 20, 2008.80 ENTOMOLOGICA AMERICANA Vol. 115(1)

An Ancient Assemblage of Scavenger Insects in Patagonia (Argentina)

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An Ancient Assemblage of Scavenger Insects in Patagonia (Argentina)

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