Bed Bugs (Hemiptera: Cimicidae) Population Diversity and First Record of Cimex hemipterus in Paris

SIMPLE SUMMARY: The bed bugs, Cimex lectularius and C. hemipterus, have undergone a significant resurgence worldwide since the 1990s. Despite reports of bed bug infestations being on the rise in recent years in France, little is known about the geographical dispersion, species composition, and inter-and intraspecific genetic variation among bed bug populations in the Paris area. The collection of 1211 samples of bed bugs from different infested locations in Paris (15 arrondissements) and its suburb cities (18 cities) allowed us to highlight C. lectularius as the predominant species and to document for the first time the presence of C. hemipterus in four infested locations (15th and 19th arrondissements, Bobigny, and Villejuif) in the Paris area. Successful bidirectional sequencing of the cytochrome oxidase 1 (COI) gene for 132 specimens representing processed locations revealed two subpopulations of C. lectularius in Paris by neighbor-joining and network phylogenetic analyses. These results provide essential information for further epidemiological and public health studies and may help control management strategies in this metropolis. ABSTRACT: Cimex lectularius and C. hemipterus are blood-sucking insects with a long history of presence in human communities. We investigated the molecular diversity of the bed bug population of Paris and its suburb cities using cytochrome oxidase 1 (CO1) sequencing. A total of 1211 specimens belonging to different life stages were collected from 62 infested human dwellings in Paris (13 out of 20 arrondissements) and the surrounding cities (18 cities). Morphological determination and COI sequencing of 132 specimens demonstrated C. lectularius as the predominant species and, surprisingly, the presence of C. hemipterus in four infested areas of Paris and its suburb cities. Neighbor-joining tree and network analyses depicted the presence of two C. lectularius populations. Most samples from Paris and its suburb cities clustered in a major clade. The second population encompasses specimens from Paris (arrondissements 11 and 19) and its suburb cities (e.g., Bobigny, Pantin, and Montreuil) that clustered with Hungary, Czechia, and Finland. This is the second evidence for C. hemipterus infestation in France and the third in Europe, which challenges the classic pattern of C. hemipterus dispersion and implies sympatric occurrence of C. lectularius and C. hemipterus. Since Paris is one of the most popular tourist destinations in the world, our observations shed light on bed bugs’ dispersal dynamic and may help future vector control strategies.