Genetic Analysis of Bed Bug Populations Reveals Small Propagule Size Within Individual Infestations but High Genetic Diversity Across Infestations From the Eastern United States

Abstract

Bed bugs (Cimex lectularius L.) are a resurgent pest worldwide and infestations within the United States are increasing at a rapid rate. Because of the physical and psychological discomfort inflicted by their blood feeding habits, and allergies and secondary infections associated with bites, bed bugs are recognized as a significant public health problem. Although bed bug infestations are spreading and becoming more prevalent, we have a poor understanding of their dispersal patterns and sources of infestation. To help fill this gap, we conducted a genetic study of 21 bed bug infestations from the eastern United States, nearly all of which came from single rooms within residences. We genotyped samples comprised of 8-10 individuals per infestation at nine polymorphic microsatellite loci. Despite high genetic diversity across all infestations, with 5-17 alleles per locus (mean = 10.3 alleles per locus), we found low genetic diversity (1-4 alleles per locus) within all but one of the infestations. These results suggest that nearly all the studied infestations were started by a small propagule possibly consisting of a singly mated female and/or her progeny, or a female mated with multiple males that were highly related to her. All infestations were strongly genetically differentiated from each other (mean pairwise F(ST) between populations = 0.68) and we did not find strong evidence of a geographic pattern of genetic structure, indicating infestations located in closer proximity to each other were nearly as genetically differentiated as those located hundreds of kilometers away. The high level of genetic diversity across infestations from the eastern United States together with the lack of geographically organized structure is consistent with multiple introductions into the United States from foreign sources.

Genetic Variability and Geographic Diversity of the Common Bed Bug (Hemiptera: Cimicidae) Populations from the Midwest Using Microsatellite Markers

“…All loci used in this study had unique alleles in addition to those previously identified by Saenz et al (2012) and Booth et al (2012). The possible explanation that fits this scenario is outbreeding and random mating by the female bed bugs.…”

“…Previous studies by Booth et al (2012) and Saenz et al (2012) on the genetic diversity of bed bugs in the eastern United States demonstrated that microsatellite markers were a useful tool to differentiate bed bug populations within an apartment building or even across large areas (Massachusetts to Florida). Our report is the first analysis of bed bug populations in the Midwest, including Nebraska and Missouri.…”

“…Therefore, it becomes very critical to identify a population based on molecular genetic techniques. Booth et al (2011) and Saenz et al (2012) have designed microsatellite markers to differentiate bed bug populations from the East Coast. However, no data exist on the bed bug population variation from other parts of the United States.…”

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

“…People from all social and economic levels are affected by bed bugs, and bed bug infestations are found in almost every human-made structure, including hotels, apartments, hospitals, military camps, homeless shelters, office buildings and college dormitories (Potter et al, 2010). After the extensive application of organophosphate insecticides in the years following World War II, bed bug infestations were diminished; they were only rarely reported in industrialized countries after the 1950s (Snetsinger, 1997;Cooper, 2006;Harlan, 2006;Booth et al, 2012). However, since the mid-1990s, the reported number of human bed bug infestations has increased significantly, originally in North America, Western Europe and Brazil, and later in various countries in Eastern Europe (Pinto et al, 2007;Reinhardt and Siva-Jothy, 2007).…”

“…This movement may occur via furniture, clothing, used mattresses, suitcases and/or other personal possessions. Bugs may also migrate from one apartment or hotel room to another through holes in walls, water pipes, or gutters (Wang et al, 2010, Booth et al, 2012. Infestation dynamics and bed bug prevalence (C. lectularius) are important aspects of bed bug biology that have not been well studied in France.…”