ABSTRACT Fanniidae (Insecta: Diptera) is a relatively small family (ca. 350 spp.) with five genera, of which Fannia Robineau-Desvoidy, 1830 and Euryomma Stein, 1899 have Neotropical distributions. Some of these species are almost always found in forensic studies. Forensically relevant species have been neglected, despite recent forensic studies that suggest their importance for estimating post-mortem interval (PMI). Thus, current and updated keys to identify adults or larvae on carcasses are unavailable for the most important species. While immature stages are important in estimating PMI, evidence suggests that adults (Fanniidae as well as other families) may also be useful for this purpose. Here we provide a key to males of the species of Fanniidae (found on corpses and other decomposing organic matter) with a checklist of species that have been used in forensics in the Neotropical region. The key comprises all 38 species of Fannia and Euryomma that have already been successfully used in forensics, and species that are potentially useful for estimating PMI. These records were found after reviews of the literature and data from entomological collections. Photographs and illustrations of the main characters in the key are provided.

Despite their prevalence in human corpses during decomposition, Sarcophagidae are not frequently used in forensic studies due to the difficulty in their identification and to the lack of information on their biology. In this paper, we identified the species of Sarcophagidae associated to corpses and studied their relationship to decomposition stages. We analyzed preferences for different cadaveric substrates (pig and lama) and microenvironmental conditions (shade, sun) at a site located at 3600 m.a.s.l. during the spring. Two pig carcasses, one located in the shade and the other in the sun, and a third carcass of a lama located in the sun, were used. We collected 597 individuals belonging to five Sarcophagidae species: Microcerella antofagastensis Mulieri, Mariluis & Aballay (n=347), M. quimaliensis (Lopes) (n=117), M. rusca (Hall) (n=32), M. penai (Lopes) (n=5) and M. aulacophyto Pape (n=96). Both M. antofagastensis and M. quimaliensis were the effective colonizers and represented 78% of the total adults collected. Microcerella antofagastensis was the primary colonizer. Both species had a similar response against microenvironmental conditions and both preferred the pig carcass. We discuss the importance of these two species as forensic indicators and the advantages of ovoviviparity against other oviparous species under extreme arid conditions.

A pesar de ser fauna necrófaga y de estar presentes en cadáveres humanos, los Sarcophagidae no suelen utilizarse en estudios forenses debido a la dificultad en su identificación y la poca información sobre su biología. En este trabajo, se identificaron las especies de Sarcophagidae asociadas a cadáveres y se estudió su relación con los estados de descomposición. Se analizaron las preferencias por los sustratos cadavéricos (cerdo y llama) y las condiciones microambientales (sol y sombra) en un ambiente de altura (3.600 msnm), durante la primavera. Se utilizaron dos cadáveres de cerdo dispuestos al sol y a la sombra y un cadáver de llama dispuesto al sol. Se colectaron 597 individuos pertenecientes a cinco especies de Sarcophagidae: M. antofagastensis Mulieri, Mariluis & Aballay (n=347), M. quimaliensis (Lopes) (n=117), M. rusca (Hall) (n=32), M. penai (Lopes) (n=5) y M. aulacophyto Pape (n=96). Tanto M. antofagastensis, como M. quimaliensis fueron las únicas especies con colonización efectiva y representaron el 78% del total de adultos colectados. Microcerella antofagastensis fue la colonizadora primaria. Ambas especies respondieron de forma similar ante las condiciones microambientales y prefirieron el cadáver de cerdo. Se discute la importancia de M. antofagastensis y M. quimaliensis, como especies indicadoras y las posibles ventajas de la ovoviviparidad frente a otras especies ovíparas, en condiciones de extrema aridez.

In order to determine the specific composition of cadaverous arthropod fauna associated to different decomposing vertebrate substrates, we studied the carrion arthropods that feed on outdoor carcasses in San Juan province, Argentina. Arthropods were collected on animal and human remains in the field and on carcasses of domestic pig placed outdoors under controlled conditions. Forty species of carrion arthropods belonging to four orders and 15 families were recorded for the first time in this province. We present the first record of forensic fauna in Argentina of the necrophagous species Megelenophorus americanus (Coleoptera: Tenebrionidae) and three necrophilous species: Polybia ruficeps (Hymenoptera: Vespidae), Pheidole bergi (Hymenoptera: Formicidae, Myrmicinae) and Ectatoma brunneum (Hymenoptera: Formicidae, Ponerinae). Eighteen necrophagous, 18 necrophilous, one omnivorous and six adventitious species are listed on seven different cadaverous vertebrate substrates. We provide new distribution records for 18 insect species. Winter seasonality of Calliphora vicina Robineau-Desvoidy (Diptera: Calliphoridae) is also confirmed in this study.

En el presente trabajo se estudiaron los artrópodos carroñeros que acudieron a cadáveres de vertebrados al aire libre en la provincia de San Juan, Argentina. El objetivo fue inventariar la composición específica de la artropodofauna cadavérica, asociada a diferentes sustratos de vertebrados en descomposición. Se colectaron muestras de artrópodos sobre restos animales y humanos en condiciones de campo y sobre cadáveres de cerdos domésticos colocados al aire libre bajo condiciones controladas. Se registraron, por primera vez para la provincia de San Juan, 40 especies de artropodofauna tanatológica incluidas en cuatro órdenes y 15 familias. Se incorpora, como primera cita para la fauna forense argentina, un necrófago: Megelenophorus americanus Lacordaire (Coleoptera: Tenebrionidae), y tres necrófilas: Polybia ruficeps Schrottky (Hymenoptera: Vespidae), Pheidole bergi Mayr (Hymenoptera, Formicidae, Myrmicinae) y Ectatomma brunneum Smith (Hymenoptera, Formicidae, Ponerinae). Se citan 18 especies necrófagas, 18 necrófilas, una omnívora y seis oportunistas sobre siete diferentes sustratos cadavéricos de vertebrados. Se brindan nuevos registros de distribución de 18 especies de insectos. Se confirma la estacionalidad invernal de Callíphora vicina Robineau-Desvoidy (Diptera: Calliphoridae).