Muscidae e Calliphoridae (Diptera, Brachycera) associados à decomposição cadavérica no noroeste do Paraná

O presente trabalho teve como objetivo listar quais são os dípteros necrófagos na região noroeste do Paraná. As informações fazem parte de um projeto, aprovado no comitê de ética em pesquisa de animais, em desenvolvimento no IFPR Campus Umuarama. Durante o estudo, um cadáver de suíno com o peso aproximado de 10 kg foi utilizado como substrato, o qual foi colocado em uma gaiola com uma tela, para impedir a entrada de vertebrados necrófagos. A coleta dos insetos foi realizada por meio de uma armadilha modificada. A gaiola de metal que continha o substrato estava fixada no terreno do IFPR Campus Umuarama. Em relação aos insetos foram coletadas cinco espécies de Muscidae (Sarcopromusca pruna; Musca domestica; Hydrotaea aenescens; Sythesiomyia nudiseta e Stomoxys calcitrans) e seis espécies de Calliphoridae (Cochliomyia macellaria; Chrysomya albiceps; Chrysomya megacephala; Lucilia eximia; Lucilia cuprina e Hemilucilia segmentaria). Os espécimes de Stomoxys calcitrans podem ter sido coletados devido à presença de gado de corte próximo ao local. O processo de decomposição se completou em seis dias, o que pode ser devido aos altos índices de temperatura e baixos índices de umidade observados no local. Nesse período foram observados quatro estágios: fresco; enfisematoso; coliquativo e esqueletização. Estes dados são importantes para a construção de um banco de dados de espécies de importância forense.

An Accidental Intestinal Myiasis Caused by Cochliomyia macellaria

Intestinal myiasis is recognized as pseudomyiasis or accidental myiasis caused by dipteran fly larvae transmitted to humans via contaminated food or water. A case of intestinal myiasis acquired via contaminated food is reported in this case study. The patient is a 4-year-old boy who had frequent episodes of crampy abdominal pain and diarrhoea and the passage of many live worms at each time. As the child had the habit of eating ripe guava from his garden, the infection source was suggested as ripe guava, and the possibility was explored. All larvae collected from faeces and fruit were morphologically similar, and it has been identified as Cochliomyia macellaria. The treatment with several antihelmintics failed, and the recovery was achieved with a simple measure of abstinence from eating guava that came from his garden.

Optimizing a Dual-Choice Cube Olfactometer Design for Measuring Adult Secondary Screwworm (Diptera: Calliphoridae) Attraction to a Resource

Detecting and locating a carrion resource is critical for the reproduction of necrophagous insects and initiating forensically important timelines. Blow flies (Diptera: Calliphoridae) primarily use olfactory cues in the form of volatile organic compounds to locate a suitable resource. Factors governing detecting and locating a resource have been studied using various behavior assays with modifications to suit the experiment design, such as the dual-choice cube olfactometer, which was examined in the current study. Systems optimization ensures biologically relevant and consistent results across replicates. In this study, two responses were measured: 1) leaving cube for either control or treatment and 2) choice between control and treatment. Phenotype (e.g., male, non-gravid, gravid) and total blow fly, Cochliomyia macellaria (Fabricius) (Diptera: Calliphoridae), number to respond were measured. Four parameters were assessed for their impact on response: 1) adjustment time in cube before trial, 2) trial length, 3) sugar/water presence, and 4) screening type in arms. Approximately, 70% of all phenotypes responded to liver with the 30-min adjustment period where only 50% responded with other adjustment periods. Trial length had a significant impact on response (35% increase in the 8 h trial compared to shorter durations); however, significant response to treatment was lost by increasing trial length. The presence of sugar/water decreased gravid and non-gravid response by 35% but did not impact males. Screening had no influence on overall or treatment response. Data indicate experiment design impacts fly response. Future studies should optimize parameters for their given fly population prior to initiating experiments.

CALLIPHORIDAE DE INTERÉS FORENSE ASOCIADAS A TRES CEBOS DE CERDOS DOMÉSTICO (Sus scrofa L.) EN UN ÁREA RURAL, CORREGIMIENTO DE LA PINTADA, PROVINCIA DE COCLÉ, PANAMÁ

La familia Calliphoridae habita en todas las regiones biogeográficas y comprende más de 1000 especies y 150 géneros a nivel mundial. Usualmente son el primer taxón en colonizar cadáveres frescos, pues su desarrollada capacidad para detectar olores olfato les permite colonizar cadáveres horas o minutos después del deceso, pudiendo encontrarse en todos los estados de descomposición cadavérica. El presente estudio se realizó durante la temporada lluviosa, en el mes de noviembre de 2017, en el corregimiento de La Pintada, provincia de Coclé. Se utilizaron vísceras de cerdo (Sus scrofa L.) correspondientes a cerebro, hígado, y corazón. De acuerdo con el análisis de correspondencias (CPA), las especies Chrysomya megacephala y Cochliomyia macellaria fueron las más abundantes; ambas están correlacionadas positivamente, debido a que sus poblaciones fueron las más capturadas y por ende pueden ser utilizadas como las principales indicadoras forenses. Lo opuesto ocurrió con las especies Chrysomya rufifacies, Lucilia sericata y Lucilia eximia, que registraron poblaciones bajas, y de acuerdo con el análisis tienen correlación negativa.

Estudio molecular de seis cepas de Cochliomyia hominivorax (Coquerel) (Diptera: Calliphoridae) y Cochliomyia macellaria

Introducción. El gusano barrenador del ganado, Cochliomyia hominivorax (Coquerel), es una plaga de importancia económica para animales de sangre caliente, principalmente el ganado vacuno. Objetivo. Caracterizar molecularmente seis cepas de Cochliomyia hominivorax (Coquerel) y la especie Cochliomyia macellaria, por medio de las secuencias del mtADN. Materiales y métodos. El estudio se realizó durante los años 2006 y 2007, utilizando seis cepas de colonias procedentes de México, Panamá y Costa Rica, ubicadas en el Laboratorio de Biología Molecular del Instituto Smithsonian de Investigaciones Tropicales, Panamá. Se optimizaron tres cebadores de seis que fueron evaluados, por medio del método de secuenciación cíclica. Para establecer las relaciones filogenéticas entre las cepas se realizaron los análisis de Parsimonia, NJ (Neighbor-Joining), Máxima Verosimilitud y Bayesiano. Para C. macellaria se evaluaron tres cebadores que fueron utilizados para C. hominivorax. Resultados. Se obtuvieron las regiones del genoma mitocondrial NADH4–tRNA–NADH5. Todos los análisis mostraron la misma topología formando cuatro clados definidos. El primero formado por las cepas de Oaxaca y Quintana Roo, el segundo por las cepas de Chiapas, el tercero por las cepas de Costa Rica y Panamá y el cuarto por la población de Brasil, obtenida de GenBank. En C. macellaria dos cebadores lograron amplificar la región NADH4 y uno la región NADH5. Conclusión. Las amplificaciones obtenidas en esta investigación aportan información para continuar con los estudios moleculares entre las especies de C. macellaria y C. hominivorax; también para identificar el origen geográfico de las cepas.

The Succession of Flies of Forensic Importance Is Influenced by Volatiles Organic Compounds Emitted During the First Hours of Decomposition of Chicken Remains

After death, a series of primary reactions occur that produce volatile organic compounds (VOCs) that are released into the environment. In this study, we investigated if the succession of flies of forensic importance in the first hours after death is mediated by VOCs in order to better understanding of the ecology of necrophagous insects. In total, 685 adult insects (Diptera and Hymenoptera) were collected by traps baited with chicken remains at different decomposition times (0, 6, 12, 24, 36, or 48 h). Of the total of insects caught, individuals from six families of Diptera can be cataloged of forensic importance. The most abundant dipteran family was Piophilidae with 213 individuals, followed by Calliphoridae with 178 specimens. Of the total flies caught, 90% were females and the rest were males. Most of the caught females were categorized as gravid, which visited more often the decaying tissues compared to nongravid females. The abundance of the flies increased in the remains with a longer time of decomposition. Six VOCs emitted in different relative quantities were identified according to the decomposition time of the remains. An apparent association was observed between the emission of ρ-cresol with Lucilia eximia (Wiedemann), between the emission of phenol, dimethyl disulfide, and dimethyl trisulfide with Chrysomya rufifacies (Macquart), and between the emissions of indole with Cochliomyia macellaria (Fabricius).