Resumen La entomotoxicología forense, que analiza insectos necrófagos para detectar sustancias tóxicas, es crucial en la determinación de causas de muerte y la estimación del intervalo post-mortem. Este estudio se centró en Peckia intermutans (Walker) (Diptera: Sarcophagidae) como marcador para la detección de metanol, un alcohol potencialmente letal presente como adulterante en bebidas alcohólicas debido a su bajo costo y parecido con el etanol. Se desarrolló un método de cromatografía de gases-espectrometría de masas (HS-GC-MS) para detectar metanol y se estudió su efecto sobre el tiempo de desarrollo, supervivencia y morfología de las moscas de la carne. Las larvas se criaron en sustratos de hígado enriquecidos con metanol (300, 500 y 1000 mg/kg). Los resultados mostraron: el método desarrollado detectó metanol en todos los estadios; el metanol afectó el tiempo de desarrollo de las moscas; la supervivencia aumentó con una mayor concentración de metanol; y los cambios morfológicos fueron evidentes en el peso. Este estudio ofrece valiosa información sobre la investigación entomotoxicológica del Ecuador, por lo que se debe considerar los cambios morfológicos de P. intermutans para evitar estimaciones inexactas de los intervalos post-mortem.

Abstract Forensic entomotoxicology, which analyzes necrophagous insects to detect toxic substances, is crucial in determining causes of death and estimating the post-mortem interval. This study focused on Peckia intermutans (Walker) (Diptera: Sarcophagidae) as a marker for detecting methanol, a potentially lethal alcohol often added as an adulterant in alcoholic beverages due to its low cost and similarity to ethanol. A gas chromatography-mass spectrometry (HS-GC-MS) method was developed to detect methanol, and its effects on the development time, survival, and morphology of flesh flies were investigated. Larvae were reared on liver substrates enriched with methanol (300, 500, and 1000 mg/kg). Results showed: the developed method detected methanol in all instars; methanol affected the developmental time of the flies; survival increased with higher methanol concentration; and morphological changes were evident in weight. This study provides valuable information on entomotoxicological research in Ecuador, emphasizing the need to consider morphological changes in P. intermutans to avoid inaccurate estimations of post-mortem intervals.

Abstract Chrysomya albiceps (Calliphoridae) is among the earliest successional fauna on human and animal cadavers. Some immature Calliphoridae can be useful for determination of post-mortem interval. Toxins, particularly pesticides, can affect the rate of insect growth. Aluminum phosphide (AlP) is an affordable insecticide that has not been adequately entomotoxicologically evaluated. So, the impact of AlP on the developmental rate of different stages of C. albiceps was investigated. Larvae of C. albiceps were reared on the rabbit carcasses containing AlP as a treated group, and distilled water as a control group. The substances were administered by a gastric tube. The duration needed for development of C. albiceps stages was documented. Body length, width and weight of larvae were measured after 24, 48, 72 and 96 h from egg hatching. The duration of development increased significantly in the treated group compared to the control group. Larvae body measurements were significantly smaller in the treated group than in the control group. Therefore, it was demonstrated that AlP significantly influences the size of C. albiceps larvae and extends their development. During forensic application, interpretation of C. albiceps data should be used with caution when aluminum phosphide may be the cause of death. (Calliphoridae cadavers postmortem post mortem interval Toxins pesticides growth (AlP evaluated So C investigated tube documented length 24 48 7 9 hatching Therefore application death 2 4

Resumo Chrysomya albiceps (Calliphoridae) está entre as primeiras espécies a colonizar cadáveres humanos e animais. Alguns Calliphoridae imaturos podem ser úteis para a determinação do intervalo “post-mortem”. Toxinas, particularmente pesticidas, podem afetar a taxa de crescimento de insetos. O fosfeto de alumínio (AlP) é um inseticida acessível que não foi adequadamente avaliado entomotoxicologicamente. Assim, o impacto do AlP na taxa de desenvolvimento de diferentes estágios de C. albiceps foi investigado. Larvas de C. albiceps foram criadas em carcaças de coelho, contendo AlP como grupo tratado e água destilada como grupo controle. As substâncias foram administradas por sonda gástrica. A duração necessária para o desenvolvimento dos estágios de C. albiceps foi documentada. O comprimento, largura e peso do corpo das larvas foram medidos após 24, 48, 72 e 96 horas da eclosão dos ovos. A duração do desenvolvimento foi significativamente aumentada no grupo tratado, em comparação com o grupo controle. As medidas corporais das larvas foram significativamente menores no grupo tratado do que no grupo controle. Portanto, foi demonstrado que o AlP influencia significativamente o tamanho das larvas de C. albiceps e prolonga seu desenvolvimento. Durante a aplicação forense, a interpretação dos dados de C. albiceps deve ser usada com cautela, quando o fosfeto de alumínio puder ser a causa da morte. (Calliphoridae animais postmortem. postmortem post mortem . “post-mortem” Toxinas pesticidas insetos (AlP entomotoxicologicamente Assim C investigado coelho controle gástrica documentada comprimento 24 48 7 9 ovos Portanto forense cautela morte “post-mortem 2 4

ABSTRACT Sarcophagidae flies have great forensic importance, since different instars of their larval development are used in the determination of the postmortem interval (PMI) of corpses. However, for many species, intrapuparial developmental data are scarce. Here we analyzed the intrapuparial development of the sarcophagid Peckia pexata and describe the chronological and morphological changes that occur during metamorphosis. We reared approximately 330 specimens originating from the Colombian Amazon in the laboratory. Prepupae were identified by size reduction and coloration change. During the first five days of the study, four individuals were sampled every three hours, then every six hours until adult emergence. Specimens were fixed in 96% alcohol, then immersed in Carnoy solution for 24 hours and in formic acid (5%) for 48 hours for dissection and analysis of morphological changes. Four morphological phases of intrapuparial development of P. pexata were observed: 1) larva pupa apolysis, which lasted, in average, 9 h; 2) cryptocephalic pupa, 6 h; 3) phanerocephalic pupa, 6.5 h; and 4) pharate adult (transparent eyes, 48 h; yellow eyes, 216 h; pink eyes, 35 h; and red eyes, 52 h). The pharate adult was fully formed at 340 h and adult emergence occurred at 372.5 h or 15.5 days. We also described the formation of the prepupa, the pupariation and the final metamorphosis for the imago and compared it with the known events for Peckia intermutans, Peckia lambens (Sarcophagidae) and Lucilia eximia (Calliphoridae). importance PMI (PMI corpses However species scarce 33 laboratory change study 96 alcohol 2 5% 5 (5% 4 P observed 1 apolysis lasted average 3 65 6. transparent eyes 21 h. . h) 34 3725 372 372. 155 15 15. prepupa intermutans (Sarcophagidae Calliphoridae. Calliphoridae (Calliphoridae) (5 37 (Calliphoridae (

RESUMEN Las moscas Sarcophagidae tienen gran importancia forense, ya que diferentes etapas de su desarrollo larvario son utilizadas en la determinación del intervalo post mortem (IPM) de cadáveres. Sin embargo, para muchas especies los datos sobre el desarrollo intrapupal son escasos. Aquí analizamos el desarrollo intrapupal del sarcofagido Peckia pexata y describimos los cambios cronológicos y morfológicos que ocurren durante la metamorfosis. Criamos aproximadamente 330 especímenes originarios de la Amazonía colombiana en laboratorio. Prepupas se identificaron por la reducción de tamaño y cambio de color. Durante los primeros cinco días se tomaron muestras de cuatro individuos cada tres horas, y posteriormente cada seis horas hasta la emergencia de los adultos. Los especímenes se fijaron en alcohol al 96%, posteriormente se sumergieron en solución Carnoy durante 24 horas y en ácido fórmico (5%) durante 48 horas, para disección y el análisis de los cambios morfológicos. Observamos cuatro etapas del desarrollo intrapupal de P. pexata: 1) larva pupa apolisis, que duró, en promedio, 9 h; 2) pupa criptocefálica, 6 h; 3) pupa fanerocefálica, 6.5 h; y 4) adulto farado (ojos transparentes, 48 h; ojos amarillos, 216 h; ojos rosados, 35 h; y ojos rojos, 52 h). El adulto farado se formó completamente a las 340 h y la emergencia del adulto se produjo a las 372.5 h o 15,5 días. También describimos la formación de la prepupa, la pupariación y la metamorfosis final para el imago y lo comparamos con los eventos conocidos para Peckia intermutans, Peckia lambens (Sarcophagidae) y Lucilia eximia (Calliphoridae). forense IPM (IPM cadáveres embargo escasos 33 laboratorio color adultos 96 96% 2 5% 5 (5% 4 P 1 apolisis duró promedio criptocefálica 3 fanerocefálica 65 6. transparentes amarillos 21 rosados rojos h. . h) 34 3725 372 372. 155 15 15, prepupa intermutans (Sarcophagidae Calliphoridae. Calliphoridae (Calliphoridae) (5 37 (Calliphoridae (

ABSTRACT Insects attracted to cadavers can be used to estimate postmortem interval (PMI). In this study, inmature stages and adults of Dermestes maculatus and Chrysomya albiceps were collected in association with a human cadaver in a closed aquatic environment in Caquetá, Colombia, and analyzed to determine the PMI. We also conducted an experiment with a pig carcass to estimate the emersion time, which began three days after carcass submersion. The minimum PMI was 481.5 hours. Time of death, time of emersion and period of insect activity matched the actions of the murder suspects, who confessed to murdering the victim 25 days prior to the discovery of the body.

RESUMEN Los insectos atraídos a cadáveres pueden ser usados para estimar el intervalo post mortem (IPM). En este estudio, una muestra de estados inmaduros y adultos de Dermestes maculatus y Chrysomya albiceps fueron recolectados en asociación con un cadáver humano en un ambiente cerrado y acuático en Caquetá, Colombia, y analizada para determinar el IPM. Además, se condujo un experimento con un cadáver porcino para estimar el tiempo de emersión, que comenzó tres días después de la sumersión del cadáver. El IPM mínimo fue 481.5 horas. El tiempo de muerte, tiempo de emersión y el periodo de actividad insectil coincidieron con las acciones de los sospechosos del crimen, quienes confesaron haber asesinado a la víctima 25 días antes del descubrimiento del cadáver.

SUMMARY: The postmortem interval (PMI) equals the time that has elapsed since a human being has died until his postmortem examination. After death, the body experiences modifications in its physical and chemical composition know as postmortem changes expressed by signs that can be analyzed for the calculation of the MPI. The aim of the study was to describe the histological changes present in rat lingual striated musculature in different PMIs. 10 two-month-old male Sprague dawley rats were used. The animals were euthanized and left at room temperature (4-14 ?C) to sample the tongue at different PMIs (0, 6, 12, 24, 48, 72, 96 and 120 hours postmortem). The study was carried out considering the recommendations of the Guide for the Care and Use of Laboratory Animals. The samples were fixed in 10% buffered formaldehyde and processed for inclusion in paraplast. 5 μm thick sections were made and stained with HE for análisis with light microscopy. Histological changes in the striated muscle cells of the tongue were associated with the different PMIs. At 6 hours postmortem, there were initial changes in nuclear morphology and its pigmentation. At 12 and 24 hours postmortem, changes in muscle striae and an increase in the number of cases with nuclear alterations were observed. At 48 and 72 hours postmortem, cytoplasmic vacuoles, changes in myofiber coloration, and increased nuclear alterations were evident. At 92 and 120 hours postmortem, a decrease in muscle striae and cell nuclei was observed. The nuclei were pyknotic and pinpoint; there was loss of cell morphology and presence of smooth muscle. In conclusion, changes in the histology of rat lingual skeletal muscle make it possible to estimate MPI. This model could be applicable to forensic medicine.

RESUMEN: El intervalo postmortem (IPM) equivale al tiempo que ha transcurrido desde que un ser humano ha muerto hasta su examinación postmortem. Después de la muerte, el cuerpo experimenta modificaciones en su composición física y química denominados cambios postmortem expresados por signos que pueden ser analizados para el cálculo del IPM. El objetivo del estudio fue describir los cambios histológicos presentes en la musculatura estriada lingual de rata en diferentes IPM. Se utilizaron 10 ratas machos Sprague dawley de dos meses de edad. Los animales fueron eutanasiados y dejados a temperatura ambiente (4 - 14 ?C) para tomar muestras de la lengua a distintos IPM (0, 6, 12, 24, 48, 72, 96 y 120 horas postmortem). El estudio se llevó a cabo considerando las recomendaciones de la Guía para el Cuidado y Uso de Animales de Laboratorio. Las muestras fueron fijadas en formaldehido tamponado a 10 % y procesadas para su inclusión en paraplast. Se realizaron cortes de 5 μm de grosor y fueron teñidas con HE para su análisis con microscopía óptica. Los cambios histológicos en las células musculares estriadas de la lengua estaban asociados a los distintos IPM. A las 6 horas postmortem, hubo cambios iniciales en la morfología nuclear y su pigmentación. A las 12 y 24 horas postmortem, se observaron cambios en las estrías musculares y aumento en el número de casos con alteraciones nucleares. A las 48 y 72 horas postmortem, eran evidentes las vacuolas citoplasmáticas, cambios en la coloración de las miofibras y aumento en las alteraciones nucleares. A las 92 y 120 horas postmortem, se observó disminución de las estrías musculares y núcleos celulares. Los núcleos eran picnóticos y puntiformes; hubo pérdida de la morfología celular y presencia de musculo liso. En conclusión, los cambios de la histología del músculo estriado lingual de rata permiten estimar el IPM. Este modelo podría ser aplicable a la medicina forense.

Abstract Dermester ater De Geer is recorded for the first time from the state of Yucatan, Mexico. Within the field of Forensic Entomology, it is a species of relevance for its usefulness in the estimation of the postmortem interval (PMI). Adult specimens of this species were collected from mummified and dried remains of pig heads (Sus scrofa domestica Linnaeus, 1758) used as necrotraps placed in a semi-urban area. Photographs of D. ater, an identification key and illustrations for the 4 species of Dermestes present in the state are included.

Resumen Se registra por primera vez a Dermestes ater De Geer en el estado de Yucatán, México. Dentro del campo de la Entomología Forense es una especie de relevancia por su utilidad en la estimación del intervalo postmortem (IPM). Ejemplares adultos de esta especie fueron recolectados en los estados de momificación y restos secos de cabezas de cerdo (Sus scrofa domestica Linnaeus, 1758) utilizadas como necrotrampas colocadas en una zona semiurbana. Se incluyen fotografías de D. ater, una clave de identificación e ilustraciones para las 4 especies de Dermestes presentes en el estado.

SUMMARY: The postmortem interval (PMI) is an important challenge to be solved in forensic pathology, and it consists of being able to determine the time elapsed from death to the moment of autopsy. Given the unreliability of some methods due to the great influence of external factors and those specific to the corpse, forensic biochemistry has received considerable attention for its levels of safety. The city of Quito is located in the Andes mountain range at 2850 meters above sea level, however, in the literature there are no reports of measurement of these parameters at a height like this. The objective was to establish a correlation between sodium (Na+), chlorine (Cl-) and potassium (K+) of the vitreous humor and the MPI at a height of 2,850 masl. For the study, 128 samples of vitreous humor were used from 16 autopsies performed in the Zone 9 Legal Medicine Unit, in IPM of 6, 12, 24, 48, 72, 96, 120 and 144 hours. To obtain the vitreous humor, the conventional method was followed, it was divided for the 8 aliquots and it was frozen at -20 ° C until the moment of its analysis. The quantification of the concentration of electrolytes Na+, Cl- and K+ was carried out using an ISE analyzer from Roche Cobas (Roche Diagnostics) C501, calibrated for urinalysis, and no dilution was necessary. During calibration and every third sample, an internal standard was measured to correct for the effects of systematic deviation on the calibration. The statistical approach was based on a linear correlation analysis, using the Spearman correlation coefficient. The correlation between the postmortem hours and the concentrations of the different electrolytes were statistically significant. A significant linear correlation between the PMI and the increase in K+ in vitreous humor could be corroborated.

RESUMEN: El intervalo Postmortem (IPM) es un importante desafío por resolver en la patología forense, y consiste en poder determinar el tiempo transcurrido desde la muerte hasta el momento de la autopsia. Dada la poca confiabilidad de algunos métodos por la gran influencia de factores externos y propios del cadáver, la bioquímica forense ha recibido considerable atención por sus niveles de seguridad. La ciudad de Quito se ubica en la cordillera de Los Andes a 2850 msnm, sin embargo, en la literatura no existen reportes de medición de estos parámetros a una altura como ésta. El objetivo fue establecer una correlación entre sodio (Na+), cloro (Cl-) y potasio (K+) del humor vítreo del cuerpo vítreo y el IPM a la altura de la ciudad de Quito. Para el estudio se utilizaron 128 muestras de cuerpo vítreo provenientes de 16 autopsias practicadas en la Unidad de Medicina Legal Zona 9, en IPM de 6, 12, 24, 48, 72, 96, 120 y 144 horas. Para la obtención del humor vítreo se siguió el método convencional, se dividió para las 8 alícuotas y se llevó a congelación -20 °C hasta el momento de su análisis. La cuantificación de la concentración de electrolitos Na+, Cl- y Potasio+ se realizó mediante analizador ISE de Roche Cobas (Roche Diagnostics) C501, calibrado para uroanálisis, y no fue necesaria la dilución. Durante la calibración y cada tres muestras, se midió un estándar interno para corregir los efectos de la desviación sistemática en la calibración. El enfoque estadístico se basó en un análisis de correlación lineal, utilizando el coeficiente de correlación de Spearman. La correlación entre las horas postmortem y las concentraciones de los diferentes electrolitos, fueron estadísticamente significativas. Se pudo corroborar una correlación lineal significativa entre el IPM y el aumento del K+ en el HV.

Abstract This study aimed to develop a visual scale for beef color evaluation. A total of 1,165 loins were analyzed 24 h postmortem in four slaughterhouses in Mexico. In each sample, it was determined color using a visual pattern and a spectrophotometer (CIELAB scale), taking a photograph of each loin. Seven categories were identified using the visual method (from very light red to very dark red), and the instrumental color variables (L*, a*, b*, C*, and h*) were used to create prediction models for the visual categories. The scale was constructed using L* as the sole predictor, as this model explained > 90 % of the observed variation. The pattern was illustrated with photos of the samples with an L* value within the 95 % confidence interval of the mean in each category, from very light red (48.1 <L*<48.8) to very dark red (32.7 <L*<33.4). The total color difference between the categories fluctuated between 2.8 and 5.5, which suggests that these are distinguishable with the naked eye. A trained sensory panel and a consumer panel, through tests, validated the scale. Trained panelists correctly rated the samples in 92.6 % of the evaluations. In meat with dark-cutting (DC) appearance, the trained panelists had 100 % hits, and the consumer panelists 85.3 %. The proposed visual pattern is supported by instrumental measurements and proved to be technically feasible for the evaluation of color in beef by trained personnel and consumers.

Resumen El objetivo fue desarrollar una escala visual para la evaluación del color en carne de bovino. Se analizaron 1,165 lomos, a las 24 h post mortem, en cuatro rastros de la República Mexicana. En cada muestra se evaluó el color con ayuda de un patrón visual y con un espectrofotómetro (escala CIELAB), tomándose una fotografía de cada lomo. Por el método visual se identificaron siete categorías, (de rojo muy pálido a rojo muy oscuro) y las variables instrumentales del color (L*, a*, b*, C* y h*) se usaron para generar modelos de predicción de las categorías visuales. La escala se construyó utilizando L* como único predictor, pues este modelo explicó >90 % de la variación observada. El patrón se ilustró con fotos de las muestras con valor de L* dentro del intervalo de confianza al 95% de la media en cada categoría, desde rojo muy pálido (48.1<L*<48.8) hasta rojo muy oscuro (32.7<L*<33.4). La diferencia total de color entre categorías fluctuó entre 2.8 y 5.5, lo que sugiere que éstas son diferenciables a simple vista. La escala se validó mediante pruebas con un panel sensorial entrenado y otro de consumidores. Los jueces entrenados calificaron correctamente las muestras en el 92.6 % de las evaluaciones. En carne con apariencia de corte oscuro (CO), el panel entrenado tuvo 100 % de aciertos y el de consumidores 85.3 %. El patrón visual propuesto se sustenta en mediciones instrumentales y mostró ser técnicamente viable para la evaluación del color en carne de bovino por personal entrenado y por consumidores.

SUMMARY: The postmortem interval (IPM) is an important challenge to be solved in forensic pathology, and it consists in determine the time elapsed since death until the autopsy. Given the low reliability of some methods due to the great influence of external factors, Histochemistry (HQ) and Immunohistochemistry (IHQ), among others, have received considerable attention for their levels of objectivity in forensic investigation. A scoping review of experimental studies that apply HQs and IHQs methods to estimate the MPI on human cadaveric material is presented. We identified 1053 articles, of which 12 met the criteria; we added 4 articles through a manual search (n = 16 articles). Germany was the most productive country, with 8 articles. HQ techniques of AgNORs, TRAP and PAS were used in 5 studies (on sweat glands, skin, liver, bone marrow and labial mucosa), while IHQs techniques were used with different antigenic groups in 12 studies (on pancreas, brain, lung, thyroid, liver, pituitary glands, sweat glands and gingival mucosa). IPM estimates were possible with margins between 2-3 hours up to 20 days depending on the technique. The analysis of oral tissues ensures a non-invasive route, easily accessible and under natural protection to the influence of environmental factors. Although there is no single method that reliably allows these estimates, the introduction of new techniques would prevent the production of errors.

RESUMEN: El intervalo postmortem (IPM) es un importante desafío a resolver en patología forense, y consiste en poder determinar el tiempo transcurrido desde la muerte hasta el momento de la autopsia. Dada la poca confiablidad de algunos métodos por la gran influencia de factores externos, la Histoquímica (HQ) y la Inmunohistoquímica (IHQ), entre otros, han recibido considerable atención por sus niveles de objetividad en la investigación forense. Se presenta una revisión con búsqueda sistemática de estudios experimentales que apliquen métodos HQs e IHQs para la estimación del IPM sobre material cadavérico humano. Se identificaron 1053 artículos de los cuales 12 cumplieron con los criterios, a los que se agregaron 4 mediante una búsqueda manual (n=16 artículos). Alemania fue el país con más publicaciones destacando con 8 artículos. Las técnicas HQs de AgNORs, TRAP y PAS fueron utilizadas en 5 estudios (glándulas sudoríparas, piel, hígado, médula ósea y mucosa labial), mientras que las IHQs fueron empleadas con diferentes grupos antigénicos en 12 estudios (páncreas, cerebro, pulmón, tiroides, hígado, glándulas pituitarias, glándulas sudoríparas y mucosa gingival). Las estimaciones del IPM fueron posibles con márgenes entre 2-3 h. hasta los 20 días dependiendo de la técnica. El análisis de tejidos provenientes de cavidad oral asegura una vía no invasiva, de fácil acceso y bajo resguardo natural a la influencia de factores ambientales. Si bien no existe un método único que permita de manera confiable estas estimaciones, la introducción de nuevas técnicas permitiría evitar la producción de errores.

This paper presents the results on the relationship between the disarticulation sequence of Equus caballus) and the postmortem interval (PMI). For this purpose, we proposed the linear regression equation developed by Megyesi, Nawrocki and Haskell (2005) in which the local temperature data and state of conservation of Equus caballus are used to obtain the ADD (accumulated degree (°C) days) and infer the PMI. The use of forensic comparative data on animal and human remains recovered in other environmental contexts allows us to conclude that, despite the isomorphism between different species, local factors, mainly temperature, may produce a significant delay in the sequence of disarticulation of Equus caballus during the first seven months postmortem. Although this study is preliminary and further research at regional and micro-regional level is required, it can be concluded that there are no significant differences between the PMI expected, derived from Megyesi s equation, and the real PMI, so this type of measurements can be expected to be applied in discrete contexts in which environmental variables are identified and quantified. Rev Arg Antrop Biol 21(1), 2019. doi:10.17139/raab.2019.0021.01.07

En este artículo se evalúan la relación entre la secuencia de desarticulación de un ejemplar de Equus caballus) y el intervalo postmortem (IPM). Para tal efecto, se propone la ecuación de regresión lineal de Megyesi, Nawrocki y Haskell (2005) en la que se utilizan los datos de temperatura local y estado de conservación de Equus caballus para obtener el ADD (°C) acumulados por día) y así inferir el IPM. La utilización de datos comparativos forenses sobre restos animales y humanos obtenidos en otros contextos ambientales nos permite concluir que, pese al isomorfismo existente entre diferentes especies, los factores locales, principalmente la temperatura, producirían en Equus caballus un retraso significativo en la desarticulación durante los primeros siete meses postmortem. Aunque este estudio es preliminar, y son necesarias más investigaciones a nivel regional y microrregional, se concluye que entre el IPM esperado, derivado de la ecuación de Megyesi, y el IPM real no habría diferencias significativas, por lo que se espera que este tipo de mediciones puedan ser aplicadas en contextos discretos en donde las variables ambientales sean identificadas y cuantificadas. Rev Arg Antrop Biol 21(1), 2019. doi:10.17139/raab.2019.0021.01.07

Resumen Objetivos: Analizar la sucesión de insectos asociados a la descomposición de cuerpos en dos ecosistemas acuáticos en la Amazonia Andina. Metodología: Tres cadáveres fueron ubicados en una quebrada y tres en un lago, los muestreos se realizaron cada cinco horas desde el momento de la muerte hasta su esqueletización. Resultados: La descomposición total duró 14 días en la quebrada y 16 en el lago. Seis estadios de descomposición fueron observados: fresco sumergido; flotación temprana; flotación tardía; deterioro de la flotación; restos flotantes y restos sumergidos. En total se colectaron 1172 individuos en la quebrada y 1585 en el lago. Los gremios tróficos identificados fueron: trituradores; colectores; depredadores; necrófagos; sarcosaprófagos e incidentales. En la quebrada, los trituradores tricópteros fueron los más representativos en la etapa fresco sumergido. En el lago los trituradores, moscas de mayo y los depredadores hemípteros y odonatos fueron los más representativos en la etapa de flotación temprana. Los dípteros necrófagos y sarcosaprófagos fueron los más representativos en las etapas donde el cuerpo estuvo expuesto a la superficie en ambos ecosistemas. Conclusiones: El ISMP para ambos cadáveres fue similar en los dos hábitats, cada uno evidenció seis etapas de descomposición, lo que confirma que la descomposición en los ecosistemas acuáticos es diferente a la observada para los entornos terrestres.

Abstract Objectives: Analyze the succession of insects associated with the decomposition of bodies in two aquatic ecosystems in the Andean Amazon. Scope: Provide information on the insects associated with bodies that decompose within aquatic habitats and the duration times of each decomposition phase as a tool for the determination of the post-mortem submerged interval (PMSI). Methodology: Three carcasses were placed in a stream and three in a lake, the sampling carried out every five hours, from the moment of death to its skeletonization. Main results: Total decomposition lasted for 14 days in the stream and 16 days in the lake. Six decomposition stages were observed: submerged fresh, early floating, floating decay, bloated deterioration, floating remains and sunken remains. A total of 1172 organisms were collected on the carcasses in the stream and 1585 in the lake. Trophic relationships identified were: Shredders, collectors, predators, necrophages, sarcosaprophages and incidentals. In the stream, the caddisfly shredders were the most representative organisms in the submerged fresh stage. In the lake, the mayfly shredders, and hemipterous and odonate predators, were the most representative organisms in the early floating stage. The necrophagous and sarcosaprophagous diptera were the most representative organisms in the stages exposed to the surface in both ecosystems. Conclusions: The PMSI for both carcasses was similar in the two habitats, each showing six stages of decomposition, confirming that decomposition in lotic and lentic ecosystems is different from that observed for terrestrial environments.

Abstract: BACKGROUND: Asynchronous twin birth consists in deferring the birth of the second twin, when the first one inevitably occurs in early stages of gestation. CLINICAL CASE: A 39-year-old patient with bicorial twin pregnancy, achieved after in vitro fertilization treatment. Served at the Miguel Servet University Hospital due to the threat of premature delivery. Upon admission the death of the first twin was verified and it was decided to perform the delivery at week 23 + 2 weeks. Subsequently, cervical retraction was observed, with 2-3 cm dilation and cessation of uterine dynamics. The amniotic bag of the second twin remained intact, with no signs of loss of fetal well-being, so it was decided to perform the asynchronous delivery attempt. During the interval between the two twins, four cycles of tocolytic drugs with atosiban and fetal pulmonary maturation with corticosteroids were administered due to the threat of premature delivery. Finally, the cerclage was removed at 34 + 2 weeks of pregnancy, due to regular uterine dynamics, even with the administration of tocolytics, giving birth to the second twin. The newborn weighed 1810 g, had Apgar of 9 per minute and 10 at 5 minutes, and cord pH of 7.39. Its evolution was favorable and remained in the neonatal intermediate care unit for 13 days, to discharge it with 2070 g. The postmortem study of the first twin did not report morphological expression of the cause of death, nor were there signs of infection. The result of the array was normal and the karyotype was 46 XY. The microbiological study of the placenta showed no signs of chorioamnionitis. The patient was discharged three days after delivery, with satisfactory evolution and without registering incidents during the puerperium. CONCLUSIONS: Deferred delivery of the second twin is an alternative for well-selected twin pregnancies in which the birth of the first twin occurs in weeks corresponding to extreme prematurity since it could prolong pregnancy to a gestational age that improves the prognosis of the second twin .

Resumen: ANTECEDENTES: El parto gemelar asincrónico consiste en diferir el nacimiento del segundo gemelo, cuando el del primero se produce de manera inevitable en etapas tempranas de la gestación. CASO CLÍNICO: Paciente de 39 años, con embarazo gemelar bicorial, logrado después de un tratamiento de fecundación in vitro. Atendida en el Hospital Universitario Miguel Servet por amenaza de parto prematuro. A su ingreso se comprobó la muerte del primer gemelo y se decidió extraerlo en la semana 23 + 2 semanas. Posteriormente se objetivó la retracción cervical, con dilatación de 2-3 cm y cese de la dinámica uterina. La bolsa amniótica del segundo gemelo permaneció íntegra, sin signos de pérdida del bienestar fetal, por lo que se intentó el parto asincrónico. Durante el intervalo entre ambos gemelos se administraron cuatro ciclos de fármacos tocolíticos con atosiban y maduración pulmonar fetal con corticoides por amenaza de parto prematuro. Finalmente, se retiró el cerclaje a las 34 + 2 semanas del embarazo, por dinámica uterina regular, aún con la administración de tocolíticos, produciéndose el parto del segundo gemelo. El recién nacido pesó 1810 g, con Apgar de 9 al minuto y de 10 a los 5 minutos, y pH del cordón de 7.39. Su evolución fue favorable y permaneció en la unidad de cuidados intermedios neonatales durante 13 días, para darlo de alta con 2070 g. El estudio posmortem del primer gemelo no reportó expresión morfológica de la causa de muerte, ni se objetivaron signos de infección. El resultado del array fue normal y el cariotipo fue 46 XY. El estudio microbiológico de la placenta no demostró signos de corioamnionitis. La paciente fue dada de alta tres días posteriores al parto, con evolución satisfactoria y sin contratiempos durante el puerperio. CONCLUSIONES: El parto diferido del segundo gemelo es una alternativa para embarazos gemelares debidamente seleccionados en los que el parto del primer gemelo se produjo en semanas de prematurez extrema y el feto superviviente puede continuar en gestación hasta alcanzar las semanas que le permitan el mejor pronóstico.

RESUMO A entomologia forense é uma ferramenta frequentemente utilizada para estimar o intervalo de tempo entre a morte e a descoberta do corpo. Na área rural do município de Florencia, Caquetá, foi monitorada a sucessão de artrópodes associados à decomposição cadavérica, utilizando como modelo de estudo os cadáveres de três porcos (Sus scrofa). A amostragem de insetos e coleta de dados ambientais foram realizadas a cada cinco horas. A duração total do processo desde a morte até a esqueletização foi de 545 horas (22,7 dias). Foram coletados 30833 espécimes de insetos, distribuídos em nove ordens, 46 famílias, 95 gêneros e 106 espécies. Diptera foi o grupo mais representativo, com 23215 indivíduos (75,3%), seguido de Coleoptera, com 3711 indivíduos (12%) e Hymenoptera, com 3154 indivíduos (10,2%). Os estágios imaturos de Cochliomyia macellaria, Chrysomya albiceps, Hemilucilia semidiaphana e Ophyra aenescens foram as principais espécies envolvidas no consumo de tecidos e na aceleração do processo de decomposição. Devido à presença de formigas Cheliomyrmex sp., Camponotus sp. e Dinoponera sp. e de besouros Hister sp., Acylophorus sp. e Philonthus spp., não foi possível obter massas de ovos de Diptera suficientes para a criação de espécies colonizadoras. Nosso estudo fornece subsídios para determinar o intervalo post-mortem em investigações policiais e promover a entomologia forense em uma área rural da Amazônia Andina na Colômbia.

ABSTRACT Forensic entomology is a frequently used tool to estimate the time interval between death and the discovery of the corpse. Succession of arthropods associated with cadaveric decomposition was monitored in a rural area of the Municipality of Florencia, Department of Caquetá, Colombia. Three pigs (Sus scrofa) were used as study models. Insect sampling, and monitoring of carcasses and environmental conditions were carried out every five hours. The total time from death to skeletonization was of 545 hours (22.7 days). A total of 30833 insect individuals were collected. Specimens were distributed in nine orders, 46 families, 95 genera and 106 species. Diptera was the most abundant, with 23215 individuals (75.3%), followed by Coleoptera, with 3711 individuals (12%), and Hymenoptera, with 3154 individuals (10.2%). Immature stages of Cochliomyia macellaria, Chrysomya albiceps, Hemilucilia semidiaphana and Ophyra aenescens were the main species involved in tissue consumption and acceleration of the decomposition process. Due to the presence of ants Cheliomyrmex sp., Camponotus sp. and Dinoponera sp., and coleopterans Hister sp., Acylophorus sp. and Philonthus spp., it was not possible to obtain sufficient Diptera egg masses for rearing the colonizing species. These results can be used as a standard to determine the postmortem interval in criminal investigations in the rural area of the Andean Amazon, Caquetá, Colombia.

RESUMO Esta é a primeira aplicação da entomologia forense em um caso envolvendo um cadáver humano encontrado em uma área urbana do Município de Florencia, Caquetá, Colombia, no Piedemonte da Amazônia Colombiana. Três dias após a remoção do corpo da área, pupas e pupários foram coletados e identificados como Chrysomya albiceps (Wiedemann, 1819) (Diptera, Calliphoridae). O intervalo pós-morte (IPM) foi estimado com base em dados publicados previamente e verificado usando graus-horas acumulados (GHA) e desenvolvimento intrapuparial. O intervalo pós-morte mínimo estimado foi de 229 horas (9.5 dias).

ABSTRACT This is the first application of forensic entomology in a case involving a human corpse found in the urban area of the Municipality of Florencia, Caquetá, Colombia, in the Piedemont of the Colombian Amazon. Three days after removing the body from the scene, pupae and puparia were collected and identified as Chrysomya albiceps (Wiedemann, 1819) (Diptera, Calliphoridae). The postmortem interval was estimated on the basis of previously published data and verified through accumulated degree hours (ADH) and intrapuparial development. The estimated minimum postmortem interval was of 229 hours (9.5 days).

RESUMO No mundo existem poucos estudos sobre o desenvolvimento intrapupal de Diptera. Comumente, os estudos dos ciclos de vida das espécies de moscas são feitos eliminando o desenvolvimento embrionário que é muito importante, principalmente nas espécies de interesse forense. O principal objetivo foi o de analisar o desenvolvimento intrapupal de Lucilia eximia, descrevendo as mudanças morfológicas que ocorrem durante o desenvolvimento intrapupal. Foram analisados cerca de 1.600 espécimes cultivados em laboratório. Foram analisadas as fases de pré-pupa, pupa, o início da fase adulta, a imago e a emergência. Pré-pupas foram identificadas de acordo com a redução no tamanho e na alteração da coloração. Dez espécimes foram coletados a cada três horas (n=1.000), sem interrupção, até a emergência dos adultos. As pupas foram fixadas em etanol a 96%. Em seguida foram imersas em solução Carnoy por 24 horas e ácido fórmico a 5% por 48 horas para facilitar a dissecação e análises das alterações morfológicas. Foram determinados 4 estágios de desenvolvimento intrapupal. 1) Apólise larva-pupa com duração de 23 ± 1,08 h; 2) Pupa criptocefálica: 5 ± 0,53 h; 3) Pupa fanerocefálica: 92 ± 1,94 h e; 4) Adulto farado: olhos transparentes: 125 ± 2,15 h; olhos amarelos: 23 ± 0,89 h; olhos róseos: 14 ± 0,73 h e olhos vermelhos 20 ± 0,60 h. O adulto farado estava completo após 296 horas e a emergência dos adultos ocorreu com 302 ± 3,81 h. Cada fase foi descrita e comparada com o descrito para Chrysomya albiceps (Calliphoridae).

ABSTRACT There are few studies about the intra-puparial development in Diptera, nonetheless its importance has been increased because several dipteran species are of forensic interest. Studies on the life cycles of flies often disregard the changes that occur inside the pupae. The objectives of this research were to analyze the intra-puparial development of Lucilia eximia, and to describe chronological and morphological changes that occur during this stage. Around 1.600 specimens were laboratory-reared. The pre-pupae were identified by the reduction of their size and change in coloration, and 10 individuals were sampled every three hours (n=1.000) until adult emergence. The specimens were fixed in 96% alcohol, subsequently immersed in Canoy solution for 24 hours and in formic acid (5%) for 48 hours, to facilitate dissection and analysis of the morphological changes of the individuals. Four stages of the intra-pupal development of L. eximia were observed: 1) Larva-pupa apolysis, which lasted 23 ± 1.08 h; 2) Cryptocephalic pupa, 5 ± 0.53 h; 3) Phanerocephalic pupa, 92 ± 1.94 h; and 4) Pharate adult: Transparents eyes, 125 ± 2.15 h; Yellow eyes, 23 ± 0.89 h; Pink eyes, 14 ± 0.73 h; and Red eyes, 20 ± 0.60 h. The pharate adult is completely formed after 296 hours and the emergence of the adult occurred after 302 ± 3.81 h. In addition, there were included the stage of pre-pupa, pupariation and the beginning of the adult stage, Imago and adult emergence. Each stage is described and compared with those described for Chrysomya albiceps (Calliphoridae).