Human‐facilitated metapopulation dynamics in an emerging pest species,Cimex lectularius

Abstract

The number and demographic history of colonists can have dramatic consequences for the way in which genetic diversity is distributed and maintained in a metapopulation. The bed bug (Cimex lectularius) is a re-emerging pest species whose close association with humans has led to frequent local extinction and colonization, that is, to metapopulation dynamics. Pest control limits the lifespan of subpopulations, causing frequent local extinctions, and human-facilitated dispersal allows the colonization of empty patches. Founder events often result in drastic reductions in diversity and an increased influence of genetic drift. Coupled with restricted migration, this can lead to rapid population differentiation. We therefore predicted strong population structuring. Here, using 21 newly characterized microsatellite markers and approximate Bayesian computation (ABC), we investigate simplified versions of two classical models of metapopulation dynamics, in a coalescent framework, to estimate the number and genetic composition of founders in the common bed bug. We found very limited diversity within infestations but high degrees of structuring across the city of London, with extreme levels of genetic differentiation between infestations (FST = 0.59). ABC results suggest a common origin of all founders of a given subpopulation and that the numbers of colonists were low, implying that even a single mated female is enough to found a new infestation successfully. These patterns of colonization are close to the predictions of the propagule pool model, where all founders originate from the same parental infestation. These results show that aspects of metapopulation dynamics can be captured in simple models and provide insights that are valuable for the future targeted control of bed bug infestations.

Extensive Mitochondrial Heteroplasmy in Natural Populations of a Resurging Human Pest, the Bed Bug (Hemiptera: Cimicidae)

“…Szalanski et al (2008) reported multiple instances of more than one mtDNA haplotype within single infestations, inferred as resulting from introductions from multiple source populations. In contrast, three studies using nuclear microsatellite data revealed genetically depauperate infestations with four or fewer alleles per infestation, suggesting that infestations are likely founded by a single gravid female or a small group of highly related individuals , Fountain et al 2014. mtDNA sequencing of one such infestation revealed individuals both heteroplasmic and homoplasmic (see Fig.…”

“…The bed bug, an obligate ectoparasite of humans and a species of significant human health concern, exhibits a cosmopolitan distribution following a dramatic global resurgence over the past two decades. Mitochondrial and nuclear DNA studies have revealed discordant patterns of infestation, with the former suggesting that infestations are commonly formed from multiple unrelated individuals (Szalanski et al 2008), and the latter the opposite , Fountain et al 2014. After polymerase chain reaction (PCR) amplification and cloning of a 508-bp fragment of the cytochrome oxidase I (COI) subunit, we present several instances of high frequency heteroplasmy within multiple populations over a broad geographic range.…”

Spatial genetic structure and restricted gene flow in bed bugs (Cimex lectularius) populations in France

“…Microsatellite loci detected high levels of genetic differentiation between the populations studied, and no correlation between genetic differentiation and the geographic distance between collections were observed. Reduced diversity within the samples suggested that colonization occurs through strong founder effects with limited active dispersal of bed bugs outside buildings, as reported by Booth et al (2012Booth et al ( , 2015, Fountain et al (2014), andSaenz et al (2012).…”

“…Booth et al (2012Booth et al ( , 2015 and Saenz et al (2012) investigated populations in the USA and Europe, and Fountain et al (2014) analyzed population structures in England and Australia. Recently, Narain et al (2015) studied the population genetics of ten bed bug infestations in the Midwestern United States.…”

Tracing historical introductions in the Mediterranean Basin: the success story of the common genet (Genetta genetta) in Europe

“…the majority of mutations/alleles must have existed before the first introduction events), we could not estimate independently effective population sizes and mutation rates. Nevertheless, estimates of time parameters describing introduction and expansion events presented the only informative posterior distributions (sharper distribution and narrower confidence interval than prior ranges) and should thus be usable (see Fountain et al 2014). Those latter represented the only informative posterior distributions (more pointy aspect and narrower confidence interval than prior ranges).…”