ABSTRACT
Duas tecnologias alternativas para o controle de Aedes aegypti foram avaliadas: a aplicação espacial de larvicida biológico-Bti em potenciais criadouros peridomiciliares, e a liberação de machos estéreis para inviabilização reprodutiva das fêmeas do mosquito. As ações foram realizadas pelos Agentes dos Serviços de Saúde em 15 vilas da Ilha de Fernando de Noronha, e em uma área (900 imóveis) no bairro da Várzea/Recife/Pernambuco. A efetividade dos métodos foi avaliada por indicadores entomológicos,estimados pela presença, quantidade e viabilidade de ovos do mosquito, coletados em armadilhas, e por marcadores genéticos. A aplicação de Bti, com atomizador costal, ocorreu a cada 30 dias em ambas as áreas. Uma redução importante e sustentável da população de A. aegypti,por este método, foi alcançada em 2015/2016 na Várzea e, em 2016, na Ilha, onde a remoção de 18 toneladas de resíduos sólidos em 2015 contribuiu possivelmente para os resultados. Machos esterilizados com radiação gama foram produzidos em massa no laboratório e liberados em uma das vilas da Ilha. A análise espaço-temporal dos indicadores, de dez/2015a ago/2016, revelou redução expressiva da densidade populacional do mosquito e da diversidade genética da população local. Ambas as abordagens parecem ter reduzido o contato homem-vetor e os riscos de transmissão de arboviroses na Ilha, apesar da elevada competência vetorial da população local do mosquito para os vírus Zika e Dengue. Os métodos testados se mostraram eficientes e passíveis de serem integradas às ações do SUS voltadas ao controle de A. aegypti.
Two alternative technologies were evaluated for Aedes aegypti control:the spraying of a biological larvicide (Bti) in potential peridomiciliarybreeding sites and the release of sterile males to promote reproductionblockage in wild females. Actions were carried out by Agents of theHealth Services, in 15 villages of the Fernando de Noronha Island and in 900 properties from the district of Várzea, Recife-PE. The effectiveness of both methods was evaluated by entomological indicators, estimatedby the presence, quantity and viability of eggs from the mosquito collectedin traps and through genetic markers. Bti was delivered by backpacksprayer every 30 days in both areas. A significant and sustainablereduction of the A. aegypti population as a result of this technique wasachieved in 2015/2016 in Várzea and in 2016 in the Island, where it wasstrengthened by the removal of 18 tons of solid waste in 2015. Malessterilized with gamma radiation were mass-produced in the laboratoryand released in one village of the Island. The spatiotemporal analysis ofthe indicators, from Dec/2015 to Aug/2016, revealed a significant reductionin mosquito density, which impacted on the genetic diversity of thelocal population. Both approaches seem to have reduced human-vectorcontact and the risk of arbovirus transmission in the Island, althoughlocal mosquito population presented high vector competence to Zikaand Dengue virus. These methods were efficient and could be integratedinto SUS actions directed to A. aegypti control.
Subject(s)
Humans , Bacillus thuringiensis , Vector Control of Diseases , Aedes/immunology , Pest Control, Biological , EntomologyABSTRACT
The presence and integrity of the P transposon and the gypsy retrotransposon in the genome of 18 samples of natural Drosophila willistoni populations collected from a large area of South America were Southern blot screened using Drosophila melanogaster probes. The aim of this screening was provide further knowledge-base on the geographical distribution of D. willistoni and to carry out an inter-population analysis of the P and gypsy elements present in the genomes of the populations analyzed. The fragment patterns obtained indicate that both the P and gypsy elements are ancient in the D. willistoni genome, but whereas the gypsy retroelement appears to be invariable and stable the P element varies between populations and appears to still have some capacity for mobilization.
Subject(s)
Animals , DNA , DNA Transposable Elements , Drosophila/geneticsABSTRACT
Chromosomal polymorphism in natural populations of Drosophila willistoni from Uruguay and southern Brazil was investigated in order to understand the genetic characteristics and evolutionary potential of these almost geographically marginal populations. The level of chromosomal polymorphism in samples from Uruguay was higher than in those from the southernmost Brazilian state of Rio Grande do Sul. The increase in the polymorphism of these populations, in which the species almost reaches its southern limit, contradicts the low level of paracentric inversion polymorphism expected under the central-marginal chromosomal polymorphism cline previously reported. The high frequency of some inversions and the presence of unique inversions in samples from Uruguay indicate the uniqueness of these populations
Subject(s)
Animals , Chromosome Inversion , Drosophila , Polymorphism, Genetic , Brazil , UruguayABSTRACT
Temperature-dependent gonadal dysgenesis was shown to occur in the progeny of both inter- and intrastrain crosses involving two populations of Drosophila willistoni, one of which was an old laboratory stock, and the other, freshly collected from a natural population. We propose that the phenomenon observed was caused by the mobilization of transposable elements, as occurs in several other Drosophila species.