Abstract
Biological invasions are increasing globally in number and extent despite efforts to restrict their spread. Knowledge of incursion pathways is necessary to prevent new invasions and to design effective biosecurity protocols at source and recipient locations. This study uses genome‐wide single nucleotide polymorphisms (SNPs) to determine the origin of 115 incursive Aedes aegypti(yellow fever mosquito) detected at international ports in Australia and New Zealand. We also genotyped mosquitoes at three point mutations in the voltage‐sensitive sodium channel (Vssc) gene: V1016G, F1534C and S989P. These mutations confer knockdown resistance to synthetic pyrethroid insecticides, widely used for controlling invertebrate pests. We first delineated reference populations using Ae. aegypti sampled from 15 locations in Asia, South America, Australia and the Pacific Islands. Incursives were assigned to these populations using discriminant analysis of principal components (DAPC) and an assignment test with a support vector machine predictive model. Bali, Indonesia, was the most common origin of Ae. aegypti detected in Australia, while Ae. aegypti detected in New Zealand originated from Pacific Islands such as Fiji. Most incursives had the same allelic genotype across the three Vsscgene point mutations, which confers strong resistance to synthetic pyrethroids, the only insecticide class used in current, widely implemented aircraft disinsection protocols endorsed by the World Health Organization (WHO). Additionally, all internationally assigned Ae. aegypti had Vssc point mutations linked to pyrethroid resistance that are not found in Australian populations. These findings demonstrate that protocols for preventing introductions of invertebrates must consider insecticide resistance, and highlight the usefulness of genomic data sets for managing global biosecurity objectives.
Highlights
Invasive alien species are a major threat to global biodiversity, agricul‐ ture and human health and confer a great economic burden upon de‐ veloped and developing countries alike (IUCN, 2000)
If the resistance observed in laboratory studies is indicative of field re‐ sistance, the World Health Organization (WHO) aircraft disinsection protocols that rely on the use of Type I synthetic pyrethroids (IPCS, 2013; WHO, 2012) are unlikely to stop the dispersal of Ae. aegypti from regions where resistance to these insecticides is common
Current WHO protocols for preventing the unintentional dispersal of invasive invertebrates rely upon Type I synthetic pyrethroids for disinsection of aircraft
Summary
Invasive alien species are a major threat to global biodiversity, agricul‐ ture and human health and confer a great economic burden upon de‐ veloped and developing countries alike (IUCN, 2000). The high level of genetic structuring at local and regional scales in this species sug‐ gests that genome‐wide SNP analyses are likely to be informative for determining the origin of incursive mosquitoes, provided reference mosquitoes are available in sufficient numbers from a range of po‐ tential source populations. We use genome‐wide SNPs to assign Ae. aegypti intercepted at international ports in Australia and New Zealand to their likely population, country or region of origin, by comparing incursives with reference mosquitoes collected from 15 locations around the world. Our results are informative to the control and monitoring of a broad range of invasive invertebrates and demonstrate how popu‐ lation genomic data can elucidate risks associated with species and genetic incursions
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
