Resistance breakdown has been observed following the deployment of plant cultivars resistant to pests. Assessing the durability of a resistance requires long‐term experiments at least at a regional scale. We collected such data for melon resistance conferred by the Vat gene cluster to melon aphids. We examined landscape‐level populations of Aphis gossypii collected in 2004–2015, from melon‐producing regions with and without the deployment of Vat resistance and with different climates. We conducted demo‐genetic analyses of the aphid populations on Vat and non‐Vat plants during the cropping seasons. The Vat resistance decreased the density of aphid populations in all areas and changed the genetic structure and composition of these populations. Two bottlenecks were identified in the dynamics of adapted clones, due to the low levels of production of dispersal morphs and winter extinction. Our results suggest that (i) Vat resistance will not be durable in the Lesser Antilles, where no bottleneck affected the dynamics of adapted clones, (ii) Vat resistance will be durable in south‐west France, where both bottlenecks affected the dynamics of adapted clones and (iii) Vat resistance will be less durable in south‐east France, where only one of the two bottlenecks was observed.

Aphis gossypii is a cosmopolitan aphid species able to colonize hundreds of plant species from various families [1] . It causes serious damage to a wide range of crops and it is considered a major pest of cucurbits and cotton [2] . It reproduces clonally, by obligate parthenogenesis, on secondary hosts present throughout the year in the intertropical area. At higher latitude, some lineages clonally overwinter but part of the population may have a sexual reproduction in autumn on primary host such as Hibiscus syriacus , to generate cold resistant overwintering eggs [3] . It is highly challenging to distinguish A. gossypii from its sister species Aphis frangulae as both are colonizing solanaceous plants as secondary hosts but the primary host of A. frangulae is Frangula alnus [4] . This paper describes a worldwide collection of both species from December 1989 to September 2019. Aphids were collected individually on plants (19 families) or in traps. The location, the morph type and the botanical family of the host plant were registered. DNA was extracted from each aphid and amplified at 8 microsatellite loci [5] . Amplicons were analysed with ABI technology and their size was defined with Genemapper software. We named each unique combination of alleles, called a multilocus genotype (MLG), and then each individual was given its MLG. The matrix of alleles of all MLGs was run for a Bayesian analysis to describe the genetic structure of the diversity collected and then each MLG had a probability to belong to a genetic group [6 , 7] . Probability of assignation to each genetic group revealed by the analysis was reported to each individual according to its MLG. This dataset can be used to analyze host plant specificities in A. gossypii , genetic diversity in A. gossypii and relative incidence of variants in diverse geographical regions, admixture between two sister species ( Aphis gossypii and Aphis frangulae ).