ABSTRACT
Background: Aedes aegypti is the dominant vector of several arboviruses that threaten urban populations in tropical and subtropical countries. Because of the climate changes and the spread of the disease worldwide, the population at risk of acquiring the disease is increasing. Methods: This study investigated the impact of the larval habitats control (CC), nebulization (NEB), and both methods (CCâ¯+â¯NEB) using the distribution of Ae. aegypti eggs collected in urban area of Santa Bárbara d'Oeste, São Paulo State, Brazil. A total of 142,469 eggs were collected from 2014 to 2017. To verify the effects of control interventions, a spatial trend, and a predictive machine learning modeling analytical approaches were adopted. Results: The spatial analysis revealed sites with the highest probability of Ae. aegypti occurrence and the machine learning generated an asymmetric histogram for predicting the presence of the mosquito. Results of analyses showed that CC, NEB, and CCâ¯+â¯NEB control methods had a negative impact on the number of eggs collected in ovitraps, with effects on the distribution of eggs in the three weeks following the treatments, according to the predictive machine learning modeling. Conclusions: The vector control interventions are essential to decrease both occurrence of the mosquito vectors and urban arboviruses. The inference processes proposed in this study revealed the relative causal impact of distinct mosquito control interventions. The spatio-temporal and the machine learning analysis are relevant and Powered by Editorial Manager® and ProduXion Manager® from Aries Systems Corporation robust analytical approach to be employed in surveillance and monitoring the results of public health programs focused on combating urban arboviruses.
ABSTRACT
The diseases transmitted by mosquito vectors are a great public health issue. Thus, effective vector control becomes the main strategy to reduce their prevalence. However, insecticide resistance has become a huge concern for the mitigation of mosquitoes; here, we propose the use of rhamnolipids in emulsion with clove oil against Aedes aegypti and Culex quinquefasciatus. The toxicity of rhamnolipids and clove oil to two species of mosquitoes transmitting tropical diseases was investigated. After 24 h, the LC50 was 140 mg/L when rhamnolipids were used and 154 mg/L when clove oil was used against Aedes aegypti larvae. In the case of Culex quinquefasciatus, the LC50 was 130 mg/L for rhamnolipids and 19 mg/L for clove oil. When the concentrations of the upper limits of one of the solutions (rhamnolipid or clove oil) were mixed, 100% mortality was obtained after 24 h. The bioassay of insecticidal action for solutions of rhamnolipids and clove oil in the lower limit, upper limit, and lethal concentration 50 to determine the effect on 50% of the population (KD50) achieved low results from KD50 to the upper limit compared to the other concentrations for both Aedes aegypti and Culex quinquefasciatus. The rhamnolipids and clove oil at the upper limit concentration had the greatest repellent activity against the two mosquito species. Bioassays using different concentrations of rhamnolipids revealed variations in the morphology of the intestinal epithelium (800 mg/L). A concentration of 900 mg/L led to the most severe morphological changes in the organization of the epithelium and the cells lining the intestines of these larvae. When larvae were exposed to a concentration of 1000 mg/L, the marginalization of chromatin in the nucleus of epithelial cells was very severe, indicating the onset of cell death.Key points⢠The toxicity of rhamnolipids and clove oil has a larvicidal, insecticidal, and repellent effect.⢠The combination of concentrations of these compounds enhances their action.⢠Different concentrations of rhamnolipids led to severe morphological changes in the organization of the epithelium and the cells and the intestines of larvae.
Subject(s)
Culicidae , Oils, Volatile , Animals , Cell Death , Glycolipids , Oils, Volatile/pharmacologyABSTRACT
BACKGROUND: Dengue is an arbovirus disease that threatens approximately 200 million people annually worldwide. Aedes (Stegomyia) aegypti (Linnaeus, 1762) is anthropophilic mosquito, extremely well adapted to the urban environment and utilizes varied habitats for egg-laying and development. This study analysed the distribution of mosquito larvae and eggs in urban area of Santa Bárbara d'Oeste, São Paulo, Brazil. The spatial correlation between locations in which people store recyclable materials and the distribution of larvae and eggs were verified. METHODS: Larvae and ovitrap egg collections were conducted from 2014 to 2016. All persons who stored recyclable materials for living were registered and georeferenced. The Mann-Kendall test was used to verify spatial and temporal trends in the number of eggs and larvae/pupae. Euclidian distance map was constructed to correlate recyclable collectors and Ae. aegypti, and Moran's index was employed to verify their spatial autocorrelation and identification of groupings. RESULTS: A total of 137,825 eggs and 16,393 larvae were collected in different habitats from 2014 to 2016. The analyses showed that there was a spatial correlation between larvae and eggs collected, and these two kinds of surveys also presented a spatial correlation with the handling of recyclable materials. The results of the analyses showed significant spatial correlations between eggs and recyclable material collectors and between larvae and collectors. CONCLUSION: The entomological surveillance conducted using ovitraps as a proxy for the presence of Ae. aegypti is an efficient and sensitive method for monitoring the presence of mosquitoes and the impact of interventions employed for decreasing vector populations. Mosquito surveys employing ovitraps should be used more often in routine activities aiming to control dengue through vector control interventions. The locations used to store recyclable materials have a significant relationship with the maintenance of the dengue virus infection in the area. Further studies will be needed to analyse the contribution of recyclable locations, for which there is no ideal infrastructure to minimize the potential use of these materials as mosquito habitats. The entomological surveillance focused on locations of recyclable materials involving interventions that are different from those commonly used in Ae. aegypti control.
Subject(s)
Aedes/physiology , Animal Distribution , Dengue/prevention & control , Equipment Reuse , Mosquito Vectors/physiology , Oviposition , Animals , Brazil , Dengue/transmission , Environment , Larva/physiology , Population Density , Spatio-Temporal AnalysisABSTRACT
Biosurfactants are microbial metabolites with possible applications in various industrial sectors that are considered ecofriendly molecules. In recent years, some studies identified these compounds as alternatives for the elimination of vectors of tropical diseases, such as Aedes aegypti. The major bottlenecks of biosurfactant industrial production have been the use of conventional raw materials that increase production costs as well as opportunistic or pathogenic bacteria, which restrict the application of these biomolecules. The present study shows the potential of hemicellulosic sugarcane bagasse hydrolysate as a raw material for the production of a crystalline glycolipidic BS by Scheffersomyces stipitis NRRL Y-7124, which resulted in an emulsifying index (EI24) of 70 ± 3.4% and a superficial tension of 52 ± 2.9 mN.m-1. Additionally, a possible new application of these compounds as biolarvicides, mainly against A. aegypti, was evaluated. At a concentration of 800 mg.L-1, the produced biosurfactant caused destruction to the larval exoskeletons 12 h after application and presented an letal concentration (LC50) of 660 mg.L-1. Thus, a new alternative for biosurfactant production using vegetal biomass as raw material within the concept of biorefineries was proposed, and the potential of the crystalline glycolipidic biosurfactant in larvicidal formulations against neglected tropical disease vectors was demonstrated.
Subject(s)
Aedes/drug effects , Ascomycota/metabolism , Larva/drug effects , Mosquito Vectors , Saccharum/metabolism , Surface-Active Agents/metabolism , Aedes/growth & development , AnimalsABSTRACT
The abundance of parasites on a host can be affected by several factors; in this study, we investigated the influence of sex and body size of the host rodent Oligoryzomys nigripes on the abundance of ectoparasitic mites (Acari: Mesostigmata). The generalized linear model indicated that body size (indicative of age) of the host rodent O. nigripes significantly contributed to the variation in the abundance of mites on host rodents at the Experimental Station of Itirapina. This trend of increased parasitism on hosts with larger body sizes may be linked to the fact that larger individuals are able to support the coexistence of a larger number of parasites, and being more mobile, are more exposed to infection by parasites.
Subject(s)
Body Size , Mite Infestations/parasitology , Mites/growth & development , Parasite Load , Sigmodontinae/anatomy & histology , Sigmodontinae/parasitology , Animals , Female , Male , Sex FactorsABSTRACT
BACKGROUND: The study of the distribution and ecology of sandfly species is essential for epidemiological surveillance and estimation of the transmission risk of Leishmania spp. infection. FINDINGS: In the present study, sandflies were captured in native fragmented forest areas in Rubião Júnior district, Botucatu municipality, São Paulo state, Brazil, between September 2001 and January 2005. A minimum of two automatic light traps were installed per night from 6 pm to 8 am, in different months, resulting in approximately 900 collecting hours. During this period, 216 sandfly specimens of sixteen species were captured. Pintomyia monticola and Brumptomyia guimaraesi were the most abundant with 56 specimens (25.93%) captured per species, followed by Pintomyia fischeri 28 (12.96%) and Psathyromyia pascalei 18 (8.33%). Other captured species were Lutzomyia amarali, Sciopemyia sordellii, Psathyromyia aragaoi, Nyssomyia whitmani, Migonemyia migonei, Pintomyia bianchigalatiae, Pintomyia misionensis, Brumptomyia carvalheiroi, Brumptomyia cardosoi, Brumptomyia cunhai, Brumptomyia nitzulescui, Brumptomyia brumpti and Brumptomyia spp. represented by 58 (26.85%) specimens. CONCLUSIONS: Although less frequently found, the presence of Pintomyia fischeri, Nyssomyia whitmani and Migonemyia migonei, known vectors of Leishmania braziliensis, indicates risk of American cutaneous leishmaniasis occurrence. Moreover, the absence of Lutzomyia longipalpis-the main vector of Leishmania infantum chagasi, which is the agent of American visceral leishmaniasis-suggests that there is no risk of introduction and establishment of this disease in the studied area.
ABSTRACT
Background: The study of the distribution and ecology of sandfly species is essential for epidemiological surveillance and estimation of the transmission risk of Leishmania spp. infection. Findings: In the present study, sandflies were captured in native fragmented forest areas in Rubião Júnior district, Botucatu municipality, São Paulo state, Brazil, between September 2001 and January 2005. A minimum of two automatic light traps were installed per night from 6 pm to 8 am, in different months, resulting in approximately 900 collecting hours. During this period, 216 sandfly specimens of sixteen species were captured. Pintomyia monticola and Brumptomyia guimaraesi were the most abundant with 56 specimens (25.93%) captured per species, followed by Pintomyia fischeri 28 (12.96%) and Psathyromyia pascalei 18 (8.33%). Other captured species were Lutzomyia amarali, Sciopemyia sordellii, Psathyromyia aragaoi, Nyssomyia whitmani, Migonemyia migonei, Pintomyia bianchigalatiae, Pintomyia misionensis, Brumptomyia carvalheiroi, Brumptomyia cardosoi, Brumptomyia cunhai, Brumptomyia nitzulescui, Brumptomyia brumpti and Brumptomyia spp. represented by 58 (26.85%) specimens. Conclusions: Although less frequently found, the presence of Pintomyia fischeri, Nyssomyia whitmani and Migonemyia migonei, known vectors of Leishmania braziliensis, indicates risk of American cutaneous leishmaniasis occurrence. Moreover,the absence of Lutzomyia longipalpis-the main vector of Leishmania infantum chagasi, which is the agent of American visceral leishmaniasis-suggests that there is no risk of introduction and establishment of this disease in the studied area.
Subject(s)
Grassland , Leishmaniasis, Cutaneous/epidemiologyABSTRACT
Background The study of the distribution and ecology of sandfly species is essential for epidemiological surveillance and estimation of the transmission risk of Leishmania spp. infection. Findings In the present study, sandflies were captured in native fragmented forest areas in Rubião Júnior district, Botucatu municipality, São Paulo state, Brazil, between September 2001 and January 2005. A minimum of two automatic light traps were installed per night from 6 pm to 8 am, in different months, resulting in approximately 900 collecting hours. During this period, 216 sandfly specimens of sixteen species were captured. Pintomyia monticola and Brumptomyia guimaraesi were the most abundant with 56 specimens (25.93%) captured per species, followed by Pintomyia fischeri 28 (12.96%) and Psathyromyia pascalei 18 (8.33%). Other captured species were Lutzomyia amarali, Sciopemyia sordellii, Psathyromyia aragaoi , Nyssomyia whitmani, Migonemyia migonei, Pintomyia bianchigalatiae, Pintomyia misionensis, Brumptomyia carvalheiroi , Brumptomyia cardosoi, Brumptomyia cunhai, Brumptomyia nitzulescui, Brumptomyia brumpti and Brumptomyia spp . represented by 58 (26.85%) specimens. Conclusions Although less frequently found, the presence of Pintomyia fischeri, Nyssomyia whitmani and Migonemyia migonei , known vectors of Leishmania braziliensis, indicates risk of American cutaneous leishmaniasis occurrence. Moreover, the absence of Lutzomyia longipalpis -the main vector of Leishmania infantum chagasi, which is the agent of American visceral leishmaniasis-suggests that there is no risk of introduction and establishment of this disease in the studied area.
ABSTRACT
The study of the distribution and ecology of sandfly species is essential for epidemiological surveillance and estimation of the transmission risk of Leishmania spp. infection. Findings In the present study, sandflies were captured in native fragmented forest areas in Rubião Júnior district, Botucatu municipality, São Paulo state, Brazil, between September 2001 and January 2005. A minimum of two automatic light traps were installed per night from 6 pm to 8 am, in different months, resulting in approximately 900 collecting hours. During this period, 216 sandfly specimens of sixteen species were captured. Pintomyia monticola and Brumptomyia guimaraesi were the most abundant with 56 specimens (25.93%) captured per species, followed by Pintomyia fischeri 28 (12.96%) and Psathyromyia pascalei 18 (8.33%). Other captured species were Lutzomyia amarali, Sciopemyia sordellii, Psathyromyia aragaoi, Nyssomyia whitmani, Migonemyia migonei, Pintomyia bianchigalatiae, Pintomyia misionensis, Brumptomyia carvalheiroi, Brumptomyia cardosoi, Brumptomyia cunhai, Brumptomyia nitzulescui, Brumptomyia brumpti and Brumptomyia spp represented by 58 (26.85%) specimens. Conclusions Although less frequently found, the presence of Pintomyia fischeri, Nyssomyia whitmani and Migonemyia migonei, known vectors of Leishmania braziliensis, indicates risk of American cutaneous leishmaniasis occurrence. Moreover, the absence of Lutzomyia longipalpis -the main vector of Leishmania infantum chagasi, which is the agent of American visceral leishmaniasis-suggests that there.
Subject(s)
Humans , Animals , Ecology , Insect Vectors , Leishmaniasis/pathology , Culicidae , Leishmania/pathogenicityABSTRACT
Because of the high adaptive capacity of mosquitoes, studies that focus on transitional environments become very important, such as those in rural areas, which are considered as bridges between wild diseases and human populations of urban areas. In this study, a survey of the existing species of mosquitoes was performed in an Atlantic Forest area of the city of Santa Bárbara d'Oeste, São Paulo state, Brazil, using traps for immatures and analyzing the frequency and distribution of these insects over the sampling months. Five mosquito species were found: Aedes albopictus (the most frequent species), Aedes aegypti, Aedes fluviatilis, Culex quinquefasciatus, and Toxorhynchites theobaldi. The 4,524 eggs collected in ovitraps showed the presence of the tribe Aedini. Aedes aegypti and Ae. albopictus were identified after larval hatching in the laboratory, with different spatial distributions: the first of which coincides with the area of greatest diversity calculated using the Simpson index, while the second does not. The association of ecological analysis of spatial diversity with simple methods of data collection enables the identification of possible epidemiological risk situations and is a strategy that may be implemented to monitor ecological processes resulting from the interaction among different species of mosquitoes.
Subject(s)
Ecosystem , Aedes/physiology , Animals , Brazil , Culicidae/physiology , EntomologyABSTRACT
Spatial evaluation of Culicidae (Diptera) larvae from different breeding sites: application of a geospatial method and implications for vector control. This study investigates the spatial distribution of urban Culicidae and informs entomological monitoring of species that use artificial containers as larval habitats. Collections of mosquito larvae were conducted in the São Paulo State municipality of Santa Bárbara d' Oeste between 2004 and 2006 during house-to-house visits. A total of 1,891 samples and nine different species were sampled. Species distribution was assessed using the kriging statistical method by extrapolating municipal administrative divisions. The sampling method followed the norms of the municipal health services of the Ministry of Health and can thus be adopted by public health authorities in disease control and delimitation of risk areas. Moreover, this type of survey and analysis can be employed for entomological surveillance of urban vectors that use artificial containers as larval habitat.
Avaliação espacial de formas larvais de Culicidae (Diptera) em diferentes criadouros: aplicação de um método geoespacial e implicações para o controle de vetores. Este estudo investiga a distribuição espacial da fauna urbana e de Culicidae e informa o monitoramento entomológico de espécies que usam recipientes artificiais como habitat larval. Coletas de larvas de mosquitos foram realizadas no município paulista de Santa Bárbara d' Oeste entre os anos de 2004 e 2006, durante visitas casa-a-casa. Um total de 1.891 amostras foi considerado, com nove espécies diferentes coletadas. A distribuição das espécies foi avaliada através do método de krigagem estatística extrapolando as divisões administrativas do município. O método de coleta adotado no presente estudo está de acordo com os métodos sugeridos aos serviços de saúde municipais pelo Ministério da Saúde e pode, portanto, ser adotado pelas autoridades públicas de saúde no controle da doença e delimitação das áreas de risco. Além disso, este tipo de levantamento e análise pode ser empregado como vigilância entomológica de espécies de mosquitos vetores que usam recipientes artificiais como habitat larval em áreas urbanas.
ABSTRACT
Under natural environmental conditions, blowflies utilize discrete and ephemeral feeding resources such as decaying carcasses. Competition for food on such feeding substrates is usually very severe, and only the individuals that are capable of attaining the critical larval weight for pupation will be able to survive. This critical weight is hitherto unknown for several blowfly species; therefore, the current work is aimed at obtaining such a critical value for four blowfly species of the genera Chrysomya and Lucilia, deploying two types of feeding substrate, namely, artificial diet and macerated bovine meat. On the whole, the critical weights ranged from 30 to 35 mg. The lowest larval weight which permitted pupation was 30.0 mg for Chrysomya megacephala reared on macerated bovine meat. This species was also the best adapted to pupation at low larval weights in relation to the maximum larval weight for males. Regarding the pupation of females, the best-adapted individual was a C. albiceps specimen exhibiting a critical weight that was equal to 39.20 percent of the maximum value obtained. Concerning all the species and diet types, the female individuals exhibited the lowest critical weights that produced viable pupae, probably representing an evolutionary strategy that favoured the survival of females, responsible for the egg formation, contributing to the establishment of future generations. Regarding the loss (in percentage) of adult biomass in relation to the third instar larvae, the females of C. megacephala lost less weight than males in both feeding substrates. On the other hand, such a loss of weight occurred in males of C. albiceps and L. cuprina.
Em ambiente natural, as moscas-varejeiras utilizam como alimento, substratos discretos e efêmeros, como por exemplo, carcaças em decomposição. Normalmente, o nível de competição por alimento nesses substratos é bastante severo, e somente vão sobreviver os indivíduos que atingiram o peso larval crítico para pupação. Como esse valor não é conhecido para várias espécies de moscas-varejeiras, o objetivo do presente trabalho foi de obter esse peso crítico para quatro espécies de moscas-varejeiras dos gêneros Chrysomya e Lucilia, em dois tipos de substrato alimentar: dieta artificial e carne bovina moída. Os pesos críticos geralmente se situaram na faixa de 30 a 35 mg. O menor peso larval que permitiu a pupação foi de 30,0 mg em C. megacephala criada em carne bovina moída. Esta espécie também foi a mais adaptada a empupar com pesos larvais baixos em relação ao peso larval máximo para machos. Já a fêmea melhor adaptada a empupar foi uma C. albiceps com peso crítico representando 39,20 por cento do máximo obtido. Os menores pesos críticos que deram origem a pupas foram observados em fêmeas, para todas as espécies e dietas, representando provavelmente uma estratégia evolutiva que procura privilegiar a sobrevivência das fêmeas, responsáveis pela formação dos ovos, contribuindo para a formação das futuras gerações. Já com relação à perda em porcentagem, de biomassa do adulto em relação às respectivas larvas de terceiro instar, em C. megacephala as fêmeas perderam menos peso que os machos em ambas as dietas, sendo que para C. albiceps e L. cuprina, isto ocorre com os machos.
ABSTRACT
Relata-se o encontro de um exemplar macho da espécie Sciopemyia sordellii (Shannon & Del Ponte, 1927) com uma rara anomalia, apresentando oito espinhos em um gonóstilo e cinco no outro. Para essa espécie, o número de espinhos normalmente esperado em cada gonóstilo é quatro. O espécime foi capturado por meio de armadilha luminosa automática do tipo CDC, em área de mata da Floresta Estadual Edmundo Navarro de Andrade, em maio de 2004, no município de Rio Claro, Estado de São Paulo. Anomalia semelhante já foi relatada nessa espécie, sendo pela primeira vez encontrada bilateralmente. Tais achados podem causar confusão na identificação específica e levar à descrição de novas espécies, aumentando a lista de sinonímias do grupo.
This paper presents a male specimen of Sciopemyia sordellii with a rare bilateral anomaly, consisting in eight spines in a style and five in the other. This species has four spines in each style as its normal number. The specimen was captured using a CDC light trap, in a forested area in the State Park "Floresta Estadual Edmundo Navarro de Andrade", in May 2004, located in the city of Rio Claro, São Paulo State, Brazil. Similar anomaly was once described but this is the first specimen found with a bilateral alteration. It may cause confusion in taxonomic identification and even lead to description of new species, increasing the number of synonymies.
Subject(s)
Animals , Male , Animal Structures/abnormalities , Psychodidae/anatomy & histologyABSTRACT
Cutaneous (LTA) and Visceral (LVA) American Leishmaniasis incidences are increasing in human and canine hosts, especially LVA, which is expanding its range through São Paulo State. Distribution and ecology knowledge of different sand fly species is essential for leishmaniasis epidemiology vigilance. The communication of new findings of its vectors is mandatory for risk determination for transmission of these illnesses. On this study sand flies were trapped in bushed areas, in different localities at rural areas of Ipeúna, Itirapina and Analândia counties, between August and September 2007. A total of 248 specimens of nine different species were sampled in Ipeúna, six and seven specimens of two different species were trapped in Itirapina and Analândia, respectively. The most abundant species in Ipeúna was Pintomyia pessoai (37.5%), followed by Pintomyia fischeri (33.06%) and Migonemyia migonei (16.53%), all three species are considered vectors of LTA in São Paulo State. Lutzomyia longipalpis was found in Ipeúna and Analândia for the first time and its presence confirmed in Itirapina, indicating a risk of LVA establishment in the area and the need for further local studies on its ecology, especially regarding its occupation of the anthropic environment.
Subject(s)
Psychodidae , Animals , Brazil , DemographyABSTRACT
A incidência das leishmanioses tegumentar e visceral americanas, em especial esta última (LVA), em hospedeiros caninos e humanos, encontra-se em crescente processo de expansão no Estado de São Paulo. Para a vigilância epidemiológica dessas endemias, torna-se fundamental o conhecimento da distribuição e da ecologia das diferentes espécies da fauna flebotomínea vetoras. Assim, a divulgação de novos encontros de seus vetores, sobretudo da Lutzomyia longipalpis, o principal vetor da LVA, é fundamental para apontar novas áreas de risco para a transmissão dessas doenças. Neste estudo, capturas de flebotomíneos foram realizadas em ambiente domiciliar, peridomiciliar e de mata, em diferentes localidades rurais dos municípios de Ipeúna e Itirapina, entre outubro de 2001 e fevereiro de 2004. Foram utilizadas armadilhas luminosas automáticas do tipo CDC, das 18h às 8h, em 14 noites, resultando 420 horas de exposição. Foram capturados 177 flebotomíneos pertencentes a doze espécies. A espécie mais abundante, Nyssomyia neivai, apontada como a principal vetora de LTA no Estado, contribuiu com 85,4 por cento dos espécimes capturados em Ipeúna. O encontro de Lutzomyia longipalpis em uma caverna em Itirapina, aponta para o risco de estabelecimento da LVA na área e a necessidade de mais estudos locais sobre sua ecologia, sobretudo em relação à ocupação de ambientes antrópicos.
Subject(s)
Humans , Animals , Dogs , Leishmaniasis, Cutaneous/transmission , Leishmaniasis, Diffuse Cutaneous/transmission , Pest Control, Biological , Psychodidae , Zoonoses , Brazil/epidemiologyABSTRACT
Considerable importance has been given to nest construction and larval food transport to the nest as a precondition for the eusociality of insects. Most adult hymenopterans feed on liquids, although bees and a few wasps may also feed on pollen. Carrion represents an additional source of protein for some species and they will scavenge for dead animals in the wild. This paper aims at analyzing Hymenoptera visitors on a pig carcass during the process of decomposition, in the summer of 2005 and the winter of 2006 in Brazil, and comparing the results with other studies in the Neotropical region. To our knowledge, this is the first study which described the occurence of Agelaia pallipes, Polybia paulista and Scaptotrigona depilis on decomposing carcasses in southeastern Brazil. It also raises the hypothesis of possible applications of Hymenoptera to achieve more precise PMI estimations, apart from other insects already known as having great importance in such estimates.
Considerável importância tem sido dada às construções de ninhos e transporte de alimento larval para o ninho como uma pré-condição para a eusociabilidade dos insetos. Muitos adultos de himenópteros alimentam-se em líquidos, embora as abelhas e poucas vespas podem também se alimentarem de pólen. Carcaças representam uma fonte adicional de proteína para algumas espécies e elas foram uma vez observadas se alimentando de animais mortos na natureza. Este trabalho tem por objetivo analisar Hymenoptera visitantes em carcaças de porcos durante o verão de 2005 e inverno de 2006 no Brasil, ao longo dos estágios de decomposição, comparando com resultados de outros estudos na região Neotropical. Pelo nosso conhecimento, esse é o primeiro estudo que descreveu a ocorrência de Agelaia pallipes, Polybia paulista e Scaptotrigona depilis em carcaças em decomposição no sudeste do Brasil. Isso também aumenta a hipótese na possibilidade de aplicação de Hymenoptera em auxiliar a estimar o IPM de maneira mais precisa, sem levar em conta insetos que já possuem grande importância forense.
Subject(s)
Animals , Entomology , Forensic Sciences , Hymenoptera , Seasons , Swine , BrazilABSTRACT
The aims of this work was to study the life stages of Chrysomya megacephala in a circular arena allowing the combined radial post-feeding dispersal from the center of the arena of C. albiceps and C. megacephala larvae. To determine the location of each pupa, the distance from the center, the depth and weight of each pupa formed were analyzed. For the larvae of C. albiceps, females released buried deeper than males, reaching an average depth of 10.74 cm and C. megacephala larvae presented greater average results than C. albiceps for all variables, particularly distance, which was 16.02 cm for this species and 12.30 cm for C. albiceps. C. albiceps larvae preyed on 30 C. megacephala larvae in both experiments. These results could be used in forensic entomology because the evaluation of Post Mortem Interval (PMI) was one of the most important aspects of legal medicine, and it could be underestimated if the older dispersing larvae or those that dispersed longer and faster or deeper, were not taken into account.
O objetivo desse trabalho foi estudar estágios de vida de Chrysomya megacephala em uma arena circular permitindo a dispersão larval pós-alimentar combinada a partir do centro das larvas de C. megacephala e C. albiceps. Para determinar a localização de cada pupa a distância a partir do centro, a profundidade e o peso foram coletados. Do total de larvas soltas as fêmeas de C. albiceps se enterraram mais profundamente que os machos, alcançando uma profundidade de 10,74 cm. Apesar dessa diferença, as larvas de C. megacephala apresentaram resultado em média maiores para todas a variáveis, particularmente a distância, a qual foi 16,02 cm para essa espécie e 12,30 para C. albiceps. Além disso, as larvas de C. albiceps predaram 30 larvas de C. megacphala durante esse processo em ambos os experimentos. Esses estudos podem ser utilizados em Entomologia forense porque a estimativa do Intervalo Pós Morte (IPM) é um dos aspectos mais importantes em medicina legal e a não consideração das larvas que dispersam mais longe ou se enterram mais podem levar a uma subestimativa do IPM.
ABSTRACT
Chrysomya megacephala (Fabricius) (Diptera, Calliphoridae) é uma espécie de mosca-varejeira de considerável importância médico-sanitária que foi introduzida acidentalmente no Brasil nos anos 70. O objetivo do presente trabalho foi avaliar alguns aspectos da ecologia populacional desta espécie, analisando aspectos demográficos de adultos mantidos sob condições experimentais. Gaiolas de C. megacephala foram montadas com quatro diferentes densidades larvais (100, 200, 400 e 800). Para cada gaiola, foram confeccionadas duas tabelas: uma com parâmetros demográficos para a estimativa da expectativa de vida na idade inicial (e0), e outra com as estimativas de taxa reprodutiva e idade média de reprodução. Parâmetros populacionais tais como a taxa intrínseca de crescimento (r) e a taxa finita de crescimento (l) foram também calculados.
ABSTRACT
Immature and adult stages of blowflies are one of the primary invertebrate consumers of decomposing animal organic matter. When the food supply is consumed or when the larvae complete their development and migrate prior to the total removal of the larval substrate, they disperse to find adequate places for pupation, a process known as postfeeding larval dispersal. Several important ecological and physiological aspects of this process were studied since the work by Green (Ann Appl Biol 38:475, 1951) 50 years ago. An understanding of postfeeding larval dispersal can be useful for determining the postmortem interval (PMI) of human cadavers in legal medicine, particularly because this interval may be underestimated if older dispersing larvae or those that disperse longer, faster, and deeper are not taken into account. In this article, we review the process of postfeeding larval dispersal and its implications for legal medicine, in particular showing that aspects such as burial behavior and competition among species of blowflies can influence this process and consequently, the estimation of PMI.
Subject(s)
Animal Feed , Diptera/growth & development , Forensic Medicine/methods , Larva/physiology , Animals , Entomology/methods , Entomology/trends , Forensic Medicine/trends , Humans , Postmortem ChangesABSTRACT
Moscas-varejeiras usam substratos discretos e efêmeros para nutricão larval. Após a exaustão do suprimento de comida, as larvas dispersam na procura por locais para pupacão na outros recursos de alimento em um processo conhecido como dispersão larval pós- alimentar. Nesse estudo, alguns dos aspectos mais importantes desse processo foram investigados em larvas de moscas-varejeiras Chrysomya megacephala expostas a uma variacão de ciclos luz: escuro (LD) (0:24h, 12:12h e 24:0h) e incubadas em tubos cobertos com vermiculita. Para cada pupa, o peso corpóreo e a profundidade de enterramento foram determinados. Testes estatísticos foram usados para examinar a relacão entre profundidade de enterramento e o peso corpóreo e o fotoperíodo a que esse enterramento ocorreu. O estudo do comportamento de enterramento na dispersão larval pós-alimentar pode ser útil para estimar o intervalo pós-morte (IPM) em cadáveres humanos em medicina forense.