Dengue presents an immense public health challenge. Current technologies are failing to contain the geographical expansion of the mosquito vector (Aedes aegypti), resulting in a perilous spread of multiple dengue serotypes. This ground breaking project will underpin the wider implementation of a safe, sustainable, and environmentally compatible means of controlling this invasive species. Research targets include the effective eradication of Ae. aegypti from two rural hamlets where this mosquito is prevalent. Technical and operational objectives include the design and validation of critical equipment, and logistics and operational scaling. This innovative genetic technology has the potential to eliminate dengue on a continental level, resulting in universal social improvement and alleviation of the tremendous pressures being imposed upon health care systems. In the longer-term, uptake would lead to benefits such as reductions in pesticide use, significant employment, and control of the numerous other diseases transmitted by Ae. aegypti.

Oxitec is the world leader in application of synthetic biology to control of pest insects. Oxitec’s RIDL® technology relies on release of mass-reared genetically sterile (transgenic) male insects that mate with their wild pest counterparts, thereby causing a drop in population. RIDL efficacy is proven against the dengue mosquito, Ae. aegypti, reducing wild populations in Brazil by ca. 96%. A costly aspect of current technology is the means of selecting males only for release, important as the females blood-feed and transmit disease. This project aims to develop a novel method of producing male-only cohorts of RIDL mosquitoes (‘genetic sexing’) that would both markedly reduce costs and cement Oxitec’s leadership in the field. Next-generation sequencing datasets will be analysed to help develop new RIDL traits in Ae. aegypti mosquitoes, to increase the efficiency of applying our technology in the field. Development of targeted bioinformatics methodology, and successful engineering of a novel genetic sexing technique, will provide a pipeline for development of new RIDL traits in other pests important for public health and agriculture.

The aim of this project is to demonstrate a novel application of Oxitec’s genetic technology, called RIDL®, against the diamondback moth, Plutella xylostella. Diamondback moth is the world’s major pest of brassica crops, with annual control costs and losses amounting to US$4- 5 billion. This moth is difficult to control, largely due to its ability to rapidly develop resistance to insecticides; therefore new control tools are urgently required. Genetic technology has enabled the development of an alternative control method, called RIDL, for this pest. fsRIDL insects live as normal with a dietary antidote, but large numbers of single- sex (male) moths can be efficiently produced without it. For control of wild diamondback moth, RIDL males are released over the crop: after mating with wild females all female progeny die, reducing the reproductive capacity of the pest population. RIDL is species- specific in action, and therefore environmentally benign, and also self-limiting in the field and complementary to other control options. RIDL is therefore highly amenable to integration into sustainable integrated pest management strategies. This project will investigate novel genetic methods of inducing female-specific lethality to generate improved RIDL strains, going well beyond the present state of the art for insect synthetic biology. Male selection at as early a life stage as possible will provide considerable savings in insect production, resulting in increased economic feasibility to a broader range of growers, and greater acceptance from growers. Developing a potentially valuable control tool in this major pest would also provide proof-of- principle for a novel means of applying this environmentally sustainable pest control approach to the diamondback moth and other important pest species.

Translational synthetic biology is a relatively new approach to the development of precisely targeted, clean methods for controlling pest insects – agricultural pests and disease vectors such as mosquitoes. The first products have already been successfully field-tested. However, the range of available parts from which to construct the necessary genetic circuits is narrow, and the range of feasible genetic circuits correspondingly limited. In this project we will characterise and test additional components, in particular genetic switches allowing precise control over gene expression. In accord with the principles of synthetic biology, concepts of modularity, reusability and abstraction will be built in from the outset. Both designs and components will be tested in distantly related insect species to assess the extent to which these can be considered ‘standardised’ across different insects, or are likely to require species-specific modification and, if the latter, to derive general rules indicating how to do this.

Gene discovery in the diamondback moth for novel pest control; 100967 Oxitec is the world leader in genetics-based insect control, and uses novel transgenic technology to provide insecticide-free pest control solutions for agriculture and public health. Oxitec’s current targets include mosquito, fruit fly and moth pests. One of these, the diamondback moth (Plutella xylostella), is the most devastating global pest of cruciferous crops (cabbage, broccoli, oilseed rape, etc). Current control efforts, costing an estimated US$1 billion per year, generally rely on pesticides, to which diamondback moth has an extraordinary capacity to develop resistance. Oxitec’s solution would be to develop the effect of genetic sterility in the moth: after release into the field, ‘sterile’ moths mate with wild moths. As their progeny do not survive, the population will crash if sufficient sterile males are released over a sufficient period of time. In partnership with the University of Liverpool’s Centre for Genome Research – another leader in their field – we are sequencing the diamondback moth genome. This data, together with resultant information on gene expression, will enable us to generate strains of diamondback moth with very specific and useful traits. We aim to provide farmers with a highly sustainable and species-specific solution to their biggest pest problems, and this project will provide a significant boost to this work in diamondback moth and other pests.

Novel pest control in tomato; 100885 The moth, Tuta absoluta, arrived in Europe in 2006 from its native South America, where it is a major pest of tomatoes. Since its discovery in Spain it has spread and become a major concern for tomato growers all over Europe, North Africa and the Middle East. In the UK, growers face problems with the moths arriving via transport of tomatoes and related materials (e.g. packaging), and these are often resistant to the few pesticides that UK farmers are permitted to use. Biological control – release of natural predators and parasitoids – is one possible alternative, but there remains an urgent need for other chemical-free methods. Oxitec, the world leader in genetics-based insect control, and BCP Certis, one of Europe’s leading suppliers of biological control solutions, have teamed up to develop one such novel tool for this pest. Using genetic technology to develop strains of Tuta absoluta that are, in effect, genetically sterile, the partnership will provide ‘sterile’ male moths for release over tomato crops. After release into the field or glasshouse, ‘sterile’ moths mate with wild moths. As their progeny do not survive, the wild population will crash if sufficient sterile males are released over a sufficient period of time. This method will provide growers with another much-needed tool for integrated pest management and, furthermore, will help to expand biological control beyond glasshouses to outdoor crops.