Calderón-Arguedas O, Troyo A, Solano ME

Language: Spanish
References: 17
Page: 79-86
PDF size: 133.91 Kb.

ABSTRACT

INTRODUCTION: The succession of muscoid larvae, a common tool in medical-legal investigations, was studied as a criterion for the estimation of the Post Mortem Interval (PMI) in an experimental model with rabbits.
MATERIAL AND METHODS: During four trimestral cycles that began in April, June, October of 2002, and January of 2003, three New Zealand rabbits (1,8 kg) were euthanasied by cervical dislocation and exposed in a tropical premontane humid forest. Three times a week, muscoid larvae were collected from each corpse. They were fixed in ethanol 70%, cleared in lactophenol, and mounted in Hoyer’s medium for their observation by light microscopy. In addition, temperatures of the soil, soil-corpse interphase, and maggot mass were determined.
RESULTS: Even though the model did not show great variation in the entomofauna associated to each decomposition phase, the generated information could approximate a time period since death, but not the exact time of the death. The calliphorids were good indicators for the bloating phase: Hemilucilia segmentaria and Lucilia eximia were evidenced in all the sampling cycles. In the active decomposition phase, Synthesiomyia nudiseta (Diptera: Muscidae) was a highly frequent species. Larvae of Fannidae, Sepsidae, Micropezidae and Drosophilidae were collected in the last days of the observation period (advanced decomposition and dry phases). Regarding the temperatures, the maggot-mass temperature was higher during active decomposition in all the cycles. During cycles I and IV, corresponding to the dry months, the temperature of the soil-corpse interphase was also higher in the active decomposition phase.
DISCUSSION: Although analysis of larval types are not methods that precisely estimate the PMI, the information derived gives an idea of temporality and geographic location, which can be key aspects in the interpretation of the forensic analysis.

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