CARRION INSECT SUCCESSION IN AN ARID ENVIRONMENT FROM SAN JUAN, ARGENTINA

CORTEZ VEGA, ANA ROMINA; ABALLAY, FERNANDO; DIAZ NIETO, LEONARDO; AMATTA, EMILCE

San Juan

Congreso; XLI reunión anual de la sociedad de Biología de CUyo; 2023

Sociedad de Biología de Cuyo

Forensic entomology aims to determine Post Mortem Interval (PMI) or the time between the death and discovery of the body using the associated arthropods with dead bodies. Diptera and Coleoptera are the most important forensic orders and both arrive at the decomposed bodies following a specific sequence called ecological succession. This succession is affected by the size of carrion resources, temperature, and particular weather and biogeographical conditions of each region. This study aims to know the composition and succession pattern of forensic insects and its relationship with decomposition states in pigs during spring in an arid location in San Juan, Argentina. This study was conducted in Médanos Grandes, Caucete, in October 2021. Three pig carcasses were used as models of vertebrate carrion decomposition and were sampled with daily base from Fresh to Remains stages. Pitfall traps, entomological nets, and hand-picking were used to collect immature and adult arthropods. A total of 24322 specimens were collected from 10 orders and 32 families. The following fly species were identified: Chrysomya albiceps, Cochliomyia macellaria, Compsomyiops fulvicrura, Lucilia sericata and Sarconesia chlorogaster (Calliphoridae), Fannia fusconotata, F. sanihue, F. heydenni and F. femoralis (Fanniidae), Musca domestica, Muscina stabulans, Dolichophaonia trigona and Ophyra aenescens (Muscidae), Piophila casei (Piophilidae), Sarcophagidae, Anthomyidae, and Phoridae. Coleoptera species were identified: Necrobia rufipes (Cleridae), Dermestes maculatus (Dermestidae), Euspilotus eremita, E. lacordairei, E. lepidus, E. modestus, E. pavidus, E. golbachi and Xerosaprinus dyptichus (Histeridae), Anthicidae, Nitidulidae, Scarabaeidae, Staphylinidae, Tenebrionidae, and Trogidae. The arrival of Co. macellaria and Sarcophagidae flies, followed by F. fusconotata, M. domestica, C. fulvicrura, S. chlorogaster, M. stabulans, and O. aenescens was characteristic in the Fresh stage. Furthermore, in this state, we observed Calliphoridae eggs and Sarcophagidae, and Co. macellaria larvae. P. casei flies and Staphylinidae, Trogidae, and D. maculatus beetles were recorded in the Bloated stage. Larvae of Co. macellaria, C. fulvicrura, C. albiceps, M. domestica, O. aenescens and adults of C. albiceps were registered in late Bloated and the early Active Decay stages. About the beetles, Anthicidae, Histeridae, Cleridae and D. maculatus larvae were registered. Larvae of P. casei were characteristic mainly in the Advanced Decay stage. In Remain stage, the absence of Calliphoridae larvae and the presence of larvae P. casei and D. maculatus were registered. Calliphoridae and Sarcophagidae flies were primary colonizers of carcasses. Histeridae, Cleridae, Staphylinidae, and Anthicidae families bettles and C. albiceps larvae fly showed necrophilic behavior, feeding on immature stages of flies. It contributes to the characterization of the succession of carrion insects, and variations between decomposition stages were recorded, in an arid environment of San Juan, Argentina.