RESUMO
The determination of necrophagous fly specie's development time is considered an accurate method for estimating postmortem interval (PMI). However, pesticides and other chemicals can alter the flies' life cycle, inducing errors in PMI estimation. Thus, this work aimed to evaluate the effect of different doses of Terbufos (Organophosphates) on the temporal dispersion pattern and development of immature dipterans associated with decaying rat carcasses. For this, 150 g female Wistar rats received, via gavage, 200 µl of Terbufos (5 or 10 mg/kg) or distilled water (control) and, after 30 min of administration, the animals were euthanized and distributed in suspended traps to decompose under environmental conditions. The dispersing immatures were collected daily, and their development time was monitored until the emergence of adult flies. After data analysis, it was observed that Terbufos altered 1) the temporal pattern of larval dispersion; 2) the composition and structure of the colonizing assemblage (emerged adults); 3) species' development time, accelerating or delaying their cycle, depending on the dose used; and 4) the califorids and sarcophagids emergence rate, increasing the mortality of pupae from intoxicated carcasses. Thus, this work demonstrates experimentally that Terbufos directly influences the development of flies with forensic potential and discusses the implications for PMI estimation, which can assist in future investigative processes with suspected poisoning by this organophosphate.
Assuntos
Calliphoridae/efeitos dos fármacos , Entomologia Forense , Inseticidas/toxicidade , Muscidae/efeitos dos fármacos , Compostos Organotiofosforados/toxicidade , Sarcofagídeos/efeitos dos fármacos , Animais , Cadáver , Calliphoridae/crescimento & desenvolvimento , Relação Dose-Resposta a Droga , Feminino , Muscidae/crescimento & desenvolvimento , Ratos , Ratos Wistar , Sarcofagídeos/crescimento & desenvolvimentoRESUMO
In Brazil, many studies on Forensic Entomology analyze the activity and succession of flies in animal models. Data on human corpses are always collected and evaluated in isolated cases. This study aimed to list the insect species associated with crime scenes investigated by the Technical-Scientific Institute of criminal expertise of the State of Rio Grande do Norte (ITEP-RN), in the Northeast of Brazil, a region exposed to high homicide rates. In total, 10 cases were investigated, of which 50% were in the initial stage of decomposition. The examined bodies were colonized by species of three orders of insects, Diptera, Coleoptera and Hymenoptera. The order Diptera represented 96% of the total insects, being represented by the following species: Chrysomya albiceps (Wiedemann) (Diptera: Calliphoridae), Chrysomya megacephala (Fabricius) (Diptera: Calliphoridae), Chrysomya putoria (Wiedemann) (Diptera: Calliphoridae), and Cochliomyia macellaria, (Fabricius) (Diptera: Calliphoridae); Musca domestica (Linnaeus) (Diptera: Muscidae); and unidentified females of the Sarcophagidae family. Among beetles, the occurrence of Dermestes maculatus (DeGeer) (Coleoptera: Dermestidae), Necrobia rufipes (De Geer) (Coleoptera: Cleridae), and Onthophagus sp. (Scarabaeidae), as well as unidentified specimens of the families Tenebrionidae and Histeridae were recorded. In addition, specimens of Ectatomma sp. (Formicidae) were also recorded. Considering that the Rio Grande do Norte state presents a high homicide rate and the last cadaver study was conducted over a decade ago, these records update the list of species associated with cadaveric decomposition and contribute to consolidate forensic entomology in the Northeast region.
Assuntos
Cadáver , Entomologia Forense , Homicídio , Insetos , Animais , Brasil , HumanosRESUMO
Caatinga is one of the least known biomes of Brazil in relation to biodiversity. The dry condition of semiarid areas has been associated in the past with low richness of fauna and flora, not encouraging studies in this region. There is a lack of mosquito records including anophelines. Thus, to investigate the biodiversity of Anopheles mosquitoes in the Caatinga biome, we collected immature mosquitoes in aquatic habitats in a conservation reserve located in the northwestern portion of Sergipe state. The captured specimens were initially identified as Anopheles albitarsis l.s. and Anopheles argyritarsis l.s. To confirm the morphological identification, sequences were generated by cytochrome oxidase subunit I mitocondrial gene. The results showed that the specimens belong to the species Anopheles oryzalimnetes, An. argyritarsis, and Anopheles sawyeri. These are the first records of these species in this region. The presence of Anopheles in the Caatinga biome, which is characterized by arid and semiarid climatic conditions, encourages the interest in the study of biological, physiological, and behavioral adaptations, selected over time, which allow these mosquito populations to survive through the long periods of drought that is characteristic of this region.
Assuntos
Distribuição Animal , Anopheles/fisiologia , Animais , Anopheles/genética , Anopheles/crescimento & desenvolvimento , Biodiversidade , Brasil , Código de Barras de DNA Taxonômico , Complexo IV da Cadeia de Transporte de Elétrons/genética , Complexo IV da Cadeia de Transporte de Elétrons/metabolismo , Feminino , Proteínas de Insetos/genética , Proteínas de Insetos/metabolismo , Larva/genética , Larva/crescimento & desenvolvimento , Larva/fisiologia , Masculino , Proteínas Mitocondriais/genética , Proteínas Mitocondriais/metabolismo , Dados de Sequência Molecular , Filogenia , Pupa/genética , Pupa/crescimento & desenvolvimento , Pupa/fisiologia , Análise de Sequência de DNA , Especificidade da EspécieRESUMO
The current study describes the chewing lice community associated with seabird populations resident at the São Pedro and São Paulo Archipelago in the Atlantic Ocean in Pernambuco State, Brazil. Adults of three species of seabirds were captured using hand-nets for the collection of biometric data and specimens of ectoparasites. In total, 320 birds were examined (120 Sula leucogaster (Boddaert), Brown Booby; 120 Anous stolidus (L.), --Brown Noddy; and 80 Anous minutus Boie, Black Noddy) of which 95% were infested with 8,625 chewing lice, representing eight species of the genera Actornithophilus, Austromenopon, Eidmanniella, Pectinopygus, Quadraceps, and Saemundssonia. On S. leucogaster, Pectinopygus garbei (Pessôa & Guimarães) was more prevalent and had a mean and median intensity of infestation significantly greater than those recorded for Eidmanniella albescens (Piaget). On the two Noddies, the species of Actornithophilus and Quadraceps were significantly more prevalent and abundant than Austromenopon atrofulvum (Piaget) and Saemundssonia remota Timmermann Most of the louse species had a highly aggregated distribution, with k exponent of the negative binomial distribution ranging from 0.04 to 3.06. A weak but significant correlation was found between the abundance of chewing lice and morphometric variables (body weight, wing, beak, tail, and tarsus lengths). It is possible that high rates of infestation have a negative effect on the morphological characteristics of the hosts, including the health of the plumage. All the lice species collected--except for P. garbei (ex S. leucogaster)--were reported for the first time from Brazilian populations of these seabird species.
Assuntos
Amblíceros/fisiologia , Doenças das Aves/parasitologia , Iscnóceros/fisiologia , Infestações por Piolhos/veterinária , Animais , Doenças das Aves/epidemiologia , Aves , Brasil/epidemiologia , Infestações por Piolhos/epidemiologia , Infestações por Piolhos/parasitologia , Especificidade da EspécieRESUMO
Anopheles darlingi is the most important malaria vector in Central and South America. After a dramatic reduction of malaria cases in the whole Brazilian territory, with the lowest abundance being attained by 1970, the disease resurged in the Amazon region, where it is now a great public health concern. Consequently, better knowledge about vector species became urgent. We examined the genetic diversity and population structure of A. darlingi, sampled in four localities in the State of Rondônia, Brazil, using 139 amplified fragment length polymorphism marker loci. In each locality, samples were collected in two environments: a peri-domicile one (in the balconies of houses) and an extra-domicile environment (about 15 m from the house). Estimates of expected heterozygosity, Shannon diversity index and percentage of polymorphic loci showed medium to high values, with the samples from the areas closer to Porto Velho exhibiting the smallest values. There was evidence of small population differences, evaluated by F(st), genetic distance and analysis of molecular variance. Comparison between peri- and extra-domicile samples showed greater values of F(st) and genetic distance than between pairs of localities, indicating influence of environmental conditions on the genetics of populations.