New Introductions, Spread of Existing Matrilines, and High Rates of Pyrethroid Resistance Result in Chronic Infestations of Bed Bugs (Cimex lectularius L.) in Lower-Income Housing

Abstract

Infestations of the common bed bug (Cimex lectularius L.) have increased substantially in the United States in the past 10–15 years. The housing authority in Harrisonburg, Virginia, conducts heat-treatments after bed bugs are detected in a lower-income housing complex, by treating each infested unit at 60°C for 4–6 hours. However, a high frequency of recurrent infestations called into question the efficacy of this strategy. Genetic analysis using Bayesian clustering of polymorphic microsatellite loci from 123 bed bugs collected from 23 units from May 2012 to April 2013 in one building indicated that (a) 16/21 (73%) infestations were genetically similar, suggesting ineffective heat-treatments or reintroductions from within the building or from a common external source, followed by local spread of existing populations; and (b) up to 5 of the infestations represented new genotypes, indicating that 5 new populations were introduced into this building in one year, assuming they were not missed in earlier screens. There was little to no gene flow among the 8 genetic clusters identified in the building. Bed bugs in the U.S. often possess one or both point mutations in the voltage-gated sodium channel, termed knockdown resistance (kdr), from valine to leucine (V419L) and leucine to isoleucine (L925I) that confer target-site resistance against pyrethroid insecticides. We found that 48/121 (40%) bed bugs were homozygous for both kdr mutations (L419/I925), and a further 59% possessed at least one of the kdr mutations. We conclude that ineffective heat treatments, new introductions, reintroductions and local spread, and an exceptionally high frequency of pyrethroid resistance are responsible for chronic infestations in lower-income housing. Because heat treatments fail to protect from reintroductions, and pesticide use has not decreased the frequency of infestations, preventing new introductions and early detection are the most effective strategies to avoid bed bug infestations in multistory apartment buildings.

The Common bed bug (Cimex lectularius) in metropolitan France. Survey on the attitudes and practices of private- and public-sector professionals

“…The present survey confirms the perception that bed bugs are a nuisance that is growing fast. This increase has already been confirmed in North America, Europe and Australia [ 8 , 15 , 17 ]. In order to document it in metropolitan France, we could take inspiration from the model adopted in Montreal ( Règlement 03-096 sur la salubrité , l’entretien et la sécurité des logements , Ville de Montréal, 2012), for example, with an obligation for insect control companies to declare their interventions to the municipality concerned, providing simple information such as the date, the town, the neighbourhood and the semi-quantitative infestation level.…”

Identifying Current and Missing Knowledge in the Control of Pyrethroid-Resistant Triatoma infestans, Vector of Chagas Disease

“…Gellatly et al, (2016) showed that in the human head louse Pediculus capitis, a high frequency of kdr-type mutations lowers the effectiveness of permethrin formulations. Moreover, Raab et al, (2016) explained that in a building infested with the bed bug Cimex lectularius, there were 8 genetic clusters with no gene flow between them, and 40% of the insects were homozygous for two concomitant kdr mutations, responsible for the decrease in effectiveness of the insecticide.…”

Bed bugs (Cimex lectularius L.) exhibit limited ability to develop heat resistance

“…If lethal temperatures are not achieved, bed bugs may detect and respond behaviorally to sublethally heated areas by fleeing to cooler areas such as wall voids, deep within furniture, or in neighboring unheated apartments [18–20]. Bed bugs stunned by sublethal heat exposure could fall into protected areas and recover afterwards [21].…”

“…Bed bugs stunned by sublethal heat exposure could fall into protected areas and recover afterwards [21]. In one case, it was observed that bed bugs escaped from a heat-treated apartment to an adjacent unheated unit to avoid heat exposure [20]. Loudon [22] reported that a single bed bug moved from the heated exterior to the cooler interior of a luggage case in an attempt to escape lethal heat exposure.…”