Evaluation of the RIDL transgenic lineage, OX3864A of Ceratitis capitata (Wied.,1824) (Diptera:Tephritidae), compared to tsl-Vienna 8 strain, for sterile insect technique purposes

As moscas-das-frutas se constituem no maior obstáculo para a produção, processamento e comércio de frutas frescas em todo o mundo. O Brasil não é exceção e, embora as condições brasileiras sejam bastante adequadas à produção de frutas tropicais e temperadas, a fruticultura enfrenta, continuamente, o problema das moscas-das-frutas. Dentre as espécies de maior importância econômica e quarentenária, destaca-se a mosca-do-mediterrâneo Ceratitis capitata (Wied., 1824) que tem, como centro de origem, a África Equatorial, e é uma das pragas mais destrutivas, causando elevados prejuízos à fruticultura mundial. No Brasil, onde sua presença foi registrada no início do século passado, esta praga se encontra amplamente distribuída em todo o território nacional. Os processos integrados de controle de pragas e doenças, com emprego de controle biológico, monitoramento populacional da praga, sistema de informação geográfica e aplicação de técnicas de controle das populações têm se desenvolvido significativamente nos últimos anos, permitindo a obtenção de frutas de alta qualidade. Com o sucesso da aplicação da Técnica do Inseto Estéril (TIE) na erradicação da Cochliomyia hominivorax (Coquerel, 1858) da Ilha de Curaçao e da região Sudeste dos Estados Unidos, houve um estímulo para o uso de programa contra várias espécies de moscas-das-frutas. A necessidade de se buscar respostas para o uso de fontes alternativas na esterilização de insetos, notadamente o uso de raios X, em escala industrial e a busca de novos modelos que possam inovar desde o ponto de vista tecnológico a TIE, com métodos que dispensem, por completo, o uso de radiação ionizante é o desafio do presente estudo, que teve como objetivo avaliar, através de testes em laboratório e em gaiola de campo, a linhagem transgênica de Ceratitis capitata (Wied.), OX3864A, comparada à linhagem tsl Vienna 8 da mesma espécie, esterilizada por raios X, visando a sua possível aplicação em programas de controle de moscas-dasfrutas, com foco na TIE. Os resultados obtidos mostram que a criação massal da linhagem transgênica esta dominada e que a dieta adotada pela BIOFÁBRICA MOSCAMED BRASIL (BMB), para a linhagem tsl Vienna 8, pode ser usada para a criação da linhagem transgênica OX3864A sem afetar o rendimento e os padrões de qualidade requeridos para o uso da linhagem na TIE. No que diz respeito aos bioensaios em gaiola de campo, os machos de ambas linhagens apresentaram uma boa performance sexual sendo capazes de competir com machos coespécificos selvagens pela cópula com fêmeas selvagens virgens. O desempenho dos machos transgênicos OX3864A não deferiu do desempenho dos machos irradiados de tsl Vienna 8. A fim de aprofundar os estudos, necessário se faz a realização de novas pesquisas para avaliar o desempenho de linhagens transgênicas em campo abertoFruit flies are within the main barriers to fresh fruit production, processing and trade throughout the world. In that sense, Brazil is not an exception, and although Brazilian conditions are favorable to the production of tropical and temperate fruits, this industry continually faces problems related to the fruit fly. From an economical and quarantine point of view, Ceratitis capitata (Wied., 1824) can be considered the most important fruit fly specie, which has the Equatorial Africa as center of origin, is also one of the most destructive pests, causing high losses to the world fruit industry. In Brazil, where its presence has been first noticed in the beginning of the past century, nowadays this pest is widespread throughout the whole national territory. With the latest developments on biological control, pest monitoring, geographical information systems and application of population control techniques it is seen that the integrated pest management systems are allowing the production of high quality fruits. Since the successful application of the sterile insect technique on the eradication of Cochliomyia hominivorax (Coquerel, 1858) in Curaçao and in the US Southeast region, there has been an incentive to the use of this technique in programs against various fruit fly species. On the search for alternative sources for insect sterilization especially the use of X-ray in high scale and the search for new models able to innovate the sterile insect technique from a technological point of view with methods that exempt the use of ionizing irradiation is the challenge of the present study, whose aim was to evaluate through lab and field cage tests the transgenic OX3864A RIDL of Ceratitis capitata (Wied.) strain, compared to X-ray sterilized tsl Vienna 8 strain, looking for a possible application on fruit fly control programs focused on the Sterile Insect Technique (SIT). Results obtained show that the mass rearing of the transgenic strain is dominated and the diet adopted by MOSCAMED BRAZIL rearing facility, for tsl Vienna 8 can also be used for the OX3864A transgenic strain without affecting its yield and quality standards required for its use in SIT. Regarding the field cage bioassays, males from both strains presented a good sexual performance, being able to compete with wild co-specific to mate with virgin wild females. Transgenic males did not differ from irradiated tsl Vienna 8 males. Further studies on sexual performance evaluation on open field of transgenic strain is recommended in order to provide more knowledg

A perspective on the need and current status of efficient sex separation methods for mosquito genetic control

Abstract Major efforts are currently underway to develop novel, complementary methods to combat mosquito-borne diseases. Mosquito genetic control strategies (GCSs) have become an increasingly important area of research on account of their species-specificity, track record in targeting agricultural insect pests, and their environmentally non-polluting nature. A number of programs targeting Aedes and Anopheles mosquitoes, vectors of human arboviruses and malaria respectively, are currently being developed or deployed in many parts of the world. Operationally implementing these technologies on a large scale however, beyond proof-of-concept pilot programs, is hampered by the absence of adequate sex separation methods. Sex separation eliminates females in the laboratory from male mosquitoes prior to release. Despite the need for sex separation for the control of mosquitoes, there have been limited efforts in recent years in developing systems that are fit-for-purpose. In this special issue of Parasites and Vectors we report on the progress of the global Coordinated Research Program on “Exploring genetic, molecular, mechanical and behavioural methods for sex separation in mosquitoes” that is led by the Insect Pest Control Subprogramme of the Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture with the specific aim of building efficient sex separation systems for mosquito species. In an effort to overcome current barriers we briefly highlight what we believe are the three main reasons why progress has been so slow in developing appropriate sex separation systems: the availability of methods that are not scalable, the difficulty of building the ideal genetic systems and, finally, the lack of research efforts in this area