Mitochondrial and Ribosomal Internal Transcribed Spacer 1 Diversity of Cimex lectularius (Hemiptera: Cimicidae)

Abstract

Understanding genetic variation among populations of medically significant pest insects is important in studying insecticide resistance and insect dispersal. The bed bug, Cimex lectularius L. (Hemiptera: Cimicidae), is widespread hematophagus insect pest around the world, including North America, and it has recently been identified as an emerging resurgent pest. To date, no studies have been conducted on genetic variation of this species. For this study, 136 adult bed bugs representing 22 sampled populations from nine U.S. states, Canada, and Australia were subjected to genetic analysis using polymerase chain reaction (PCR) to amplify and sequence a region of the mitochondrial DNA (mtDNA) 16S rRNA gene and a portion of the nuclear rRNA internal transcribed spacer (ITS) 1 region. For the 397-bp 16S marker, a 12 nucleotide sites in total were polymorphic, and 19 unique haplotypes were observed. Heterozygosity was observed within many of the sampled populations for the mtDNA marker. This suggests that bed bug populations did not undergo a genetic bottleneck as one would expect from insecticide control during the 1940s and 1950s, but instead, that populations may have been maintained on other hosts such as birds and bats. In contrast to the high amount of heterozygosity observed with the mitochondrial DNA marker, no genetic variation in the 589-bp nuclear rRNA marker was observed. This suggests increased gene flow of previously isolated bed bug populations in the United States, and given the absence of barriers to gene flow, the spread of insecticide resistance may be rapid.

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

“…The rest of the populations showed heterozygote advantage maybe because of random mating or multiple sources introduced at one time, allowing for the exchange of multiple alleles. This agrees with studies by Szalanski et al (2008) and Booth et al (2012). The difference in these two studies is the geographic area they encompass.…”

“…The difference in these two studies is the geographic area they encompass. The Szalanski et al (2008) study covers a wider region and includes the southern Midwest, whereas the Booth et al (2012) study was limited to one apartment building. Booth et al (2012) suggested that a combination of genetic diversity and pyrethroid resistance could provide evidence for the possible sources of heterozygosity.…”

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

“…It questions the validity of the application of mtDNA to address the infestation dynamics of this species. 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.…”

“…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

“…This will require working at both the micro (i.e., at the building level) and macro (i.e., at the country, continental and global levels) geographical scales, within a well-defined hierarchical sampling design. Indeed, Szalanski et al (2008) reported that the most common mtDNA haplotype found in their study in the USA was also present in Australia, suggesting a role of international connections in bugs transportation. It remains possible that this hypothesis may be verified in the case of infestations in France.…”