Close kin dyads indicate intergenerational dispersal and barriers

The movement of individuals through continuous space is typically constrained by dispersal ability and dispersal barriers. A range of approaches have been developed to investigate these. Kindisperse is a new approach that infers intergenerational dispersal (σ) from close kin dyads, and appears particularly useful for investigating taxa that are difficult to observe individually. This study, focusing on the mosquito Aedes aegypti, shows how the same close kin data can also be used for barrier detection. We empirically demonstrate this new extension of the method using genome-wide sequence data from 266 Ae. aegypti. First, we use the spatial distribution of full-sib dyads collected within one generation to infer past movements of ovipositing female mosquitoes. These dyads indicated the relative barrier strengths of two roads, and performed favourably against alternative genetic methods for detecting barriers. The difference in variance between the sib and first cousin spatial distributions was used to infer movement over the past two generations, providing estimates of intergenerational dispersal (σ = 81.5-197.1 m.gen-1/2) and density (ρ = 833-4864 km-2). Dispersal estimates showed general agreement with those from mark-release-recapture studies. Barriers, σ, ρ, and neighbourhood size (331-526) can inform forthcoming releases of dengue-suppressing Wolbachia bacteria into this mosquito population.

Methods
Aedes aegypti mosquitoes were sampled from Jeddah, Saudi Arabia, in 2020. Genome-wide sequence data was generated from 266 mosquitoes using ddRADseq. Data were processed in the Stacksv2.0 pipeline. Specifics are listed in: https://doi.org/10.1101/2022.01.18.476819