Hentley, W. T., B. Webster, S. E. F. Evison, and M. T. Siva-Jothy. 2017. Bed bug aggregation on dirty laundry: a mechanism for passive dispersal. Scientific Reports. 7: 11668. doi: 10.1038/s41598-017-11850-5
“Bed bugs have shown a recent and rapid global expansion that has been suggested to be caused by cheap air travel. How a small, flightless and anachoretic insect that hides within its host’s sleeping area manages to travel long distances is not yet clear. Bed bugs are attracted to the odour of sleeping humans and we suggest that soiled clothing may present a similarly attractive cue, allowing bed bugs to ‘hitch-hike’ around the world after aggregating in the laundry bags of travellers. We show that (1) soiled clothing is significantly more attractive than clean clothing to active bed bugs moving within a bedroom sized arena and (2) elevation of CO2 to a level that simulates human occupancy in the same arena appears to initiate search behaviour rather than direct it. Our results show, for the first time, how leaving worn clothing exposed in sleeping areas when travelling can be exploited by bed bugs to facilitate passive dispersal.”
Olson, J. F., L. M. V. Vers, R. D. Moon, and S. A. Kells. 2017. Two compounds in bed bug feces are sufficient to elicit off-host aggregation by bed bugs, Cimex lectularius. Pest Management Science. 73: 198–205. doi: 10.1002/ps.4286
“After feeding, bed bugs aggregate in cracks and crevices near a host. Aggregation and arrestment are mediated by tactile and chemical stimuli associated with the bugs’ feces and exuviae. Volatiles derived from fecally stained filter papers were analyzed by solid-phase microextraction (SPME) and evaluated using a multichoice behavioral assay to determine their impact on bed bug aggregation. In addition, crude fecal extracts were collected in methanol, analyzed by gas chromatography coupled with electroantennogram detection (GC-EAD) and mass spectrometry (GC-MS) and evaluated in open-air multichoice behavioral assays. The SPME method was used to detect (E)-2-hexenal and (E)-2-octenal in heated bed bug feces. The presence of these two volatile components did not affect aggregation. Analysis of the crude fecal extracts revealed several semi-volatile nitrogenous compounds, a carboxylic acid and a sulfur-based compound. Adult antennae responded to compounds eluted from three regions of the crude extract using GC-EAD. A combination of two compounds, dimethyl trisulfide and methyldiethanolamine, resulted in aggregation responses equivalent to the original crude extract. Bed bug aggregation is mediated by semi-volatile compounds derived from fecal extracts, and two compounds are sufficient to elicit aggregation. The two compounds identified here could be used to enhance the effectiveness of insecticidal applications or improve monitoring techniques.”
Sivakoff, F. S., S. C. Jones, S. A. Machtley, and J. R. Hagler. 2016. Protein self-marking by ectoparasites: A case study using bed bugs (Hemiptera: Cimicidae). Journal of Medical Entomology. 53: 1370–1377. doi: 10.1093/jme/tjw117
“The ability to mark individuals is a critical feature of many entomological investigations, including dispersal studies. Insect dispersal is generally investigated using mark–release–recapture techniques, whereby marked individuals are released at a known location and then captured at a measured distance. Ectoparasite dispersal has historically been challenging to study, in part because of the ethical concerns associated with releasing marked individuals. Here, we introduce the protein self-marking technique, whereby ectoparasites mark themselves in the field by feeding on the blood of an introduced host. We demonstrate the potential of this technique using laboratory-reared bed bugs (Cimex lectularius L.) that marked themselves by feeding on either rabbit or chicken blood. We then used enzyme-linked immunosorbent assays to detect host-specific blood serum proteins in bed bugs. We assessed these protein markers’ ability to 1) distinctively identify marked individuals, 2) persist following multiple feedings on an alternate diet, 3) persist over time across a range of temperatures, and 4) transfer from marked to unmarked individuals. Protein markers were detectable in bed bugs before and after molting, remained detectible after multiple feedings on an alternate diet, persisted regardless of whether an individual was starved or fed on an alternate diet following original mark acquisition, and did not transfer between individuals. The duration of detectability depended on temperature. Our results suggest that protein self-marking is an effective technique for marking bed bugs and holds promise for use in dispersal studies of ectoparasitic insects.”
Cooper, R., C. Wang, and N. Singh. 2015. Mark-release-recapture reveals extensive movement of bed bugs (Cimex lectularius L) within and between apartments. PLoS One. 10(9): e0136462. doi:10.1371/journal.pone.0136462
“Understanding movement and dispersal of the common bed bug (Cimex lectularius L.) under field conditions is important in the control of infestations and for managing the spread of bed bugs to new locations. We investigated bed bug movement within and between apartments using mark-release-recapture (m-r-r) technique combined with apartment-wide monitoring using pitfall-style interceptors. Bed bugs were collected, marked, and released in six apartments. The distribution of marked and unmarked bed bugs in these apartments and their 24 neighboring units were monitored over 32 days. Extensive movement of marked bed bugs within and between apartments occurred regardless of the number of bed bugs released or presence/absence of a host. Comparison of marked and unmarked bed bug distributions confirms that the extensive bed bug activity observed was not an artifact of the m-r-r technique used. Marked bed bugs were recovered in apartments neighboring five of six m-r-r apartments. Their dispersal rates at 14 or 15 d were 0.0–5.0%. The estimated number of bed bugs per apartment in the six m-r-r apartments was 2,433–14,291 at 4–7 d after release. Longevity of bed bugs in the absence of a host was recorded in a vacant apartment. Marked large nymphs (3rd– 5th instar), adult females, and adult males continued to be recovered up to 57, 113, and 134 d after host absence, respectively. Among the naturally existing unmarked bed bugs, unfed small nymphs (1st– 2nd instar) were recovered up to 134 d; large nymphs and adults were still found at 155 d when the study ended. Our findings provide important insight into the behavioral ecology of bed bugs in infested apartments and have significant implications in regards to eradication programs and managing the spread of bed bugs within multi-occupancy dwellings.”
Goddard, J., M. Caprio, and I. Goddard Jerome. 2015. Diffusion rates and dispersal patterns of unfed versus recently fed bed bugs (Cimex lectularius L.). Insects. 6: 792–804. doi: 10.3390/insects6040792
“Bed bug problems have been increasing since the 1980s, and accordingly, there have been intensive efforts to better understand their biology and behavior for control purposes. Understanding bed bug diffusion rates and dispersal patterns from one site to another (or lack thereof) is a key component in prevention and control campaigns. This study analyzed diffusion rates and dispersal patterns in a population of bed bugs, recently fed and unfed, in both one-dimensional and two-dimensional settings. When placed in the middle of a 71 cm × 2.7 cm artificial lane, approximately half of the bugs regardless of feeding status stayed at or near the release point during the 10 min observation periods, while about a fourth of them walked to the end of the lane. When placed in the middle of an arena measuring 51 cm × 76 cm and allowed to walk in any direction, approximately one-fourth of bed bugs, fed or unfed, still remained near their release point (no significant difference between fed or unfed). As for long-distance dispersal, 11/50 (22%) of recently fed bed bugs moved as far as possible in the arena during the 10 min replications, while only 2/50 (4%) unfed bed bugs moved to the maximum distance. This difference was significantly different (p < 0.0038), and indicates that unfed bed bugs did not move as far as recently fed ones. A mathematical diffusion model was used to quantify bed bug movements and an estimated diffusion rate range of 0.00006 cm2/s to 0.416 cm2/s was determined, which is almost no movement to a predicted root mean squared distance of approximately 19 cm per 10 min. The results of this study suggest that bed bugs, upon initial introduction into a new area, would have a difficult time traversing long distances when left alone to randomly disperse.”
Aak, A., B. A. Rukke, A. Soleng, and M. K. Rosnes. 2014. Questing activity in bed bug populations: male and female responses to host signals. Physiological Entomology. doi: 10.1111/phen.12062
Sex differences in bed bug behavioral responses to a stimulus (human host or carbon dioxide gas) were observed. Compared to males, female bed bugs responded more strongly to the human host signal, were more active while acclimating to a new environment, had quicker responses after feeding, and remained exposed for longer periods of time during the day.
Booth, W., V. L. Saenz, R. G. Santangelo, C. Wang, C. Schal, and E. L. Vargo. 2012. Molecular markers reveal infestation dynamics of the bed bug (Hemiptera : Cimicidae) within apartment buildings. Journal of Medical Entomology. 49: 535–546. doi: 10.1603/ME11256
Researchers developed 24 high- resolution microsatellite markers for bed bugs and used these molecular markers to study infestation dynamics in three multistory apartment buildings. Data suggested that an infestation within an apartment building in Raleigh, NC, started from a single bed bug introduction followed by extensive spread. In Jersey City, NJ, two or more bed bug introductions followed by spread apparently occurred in two buildings. Bed bugs from single apartments in all buildings showed high levels of relatedness and low levels of genetic diversity. Genetic data revealed the extensive spread of bed bugs within and between adjacent rooms or apartments spanning multiple floors.
Delaunay, P. 2012. Human travel and traveling bedbugs. Journal of Travel Medicine. 19: 373–379. doi: 10.1111/j.1708-8305.2012.00653.x
“Background: A dramatic increase of reported bedbug (Cimex lectularius and Cimex hemipterus) infestations has been observed worldwide over the past decade. Bedbug infestations have also been detected across a wide range of travel accommodations, regardless of their comfort and hygiene levels. Travelers are increasingly exposed to the risks of bedbug bites, infestation of personal belongings, and subsequent contamination of newly visited accommodations and their homes. Methods: We searched Medline publications via the PubMed database. National bedbug recommendations, textbooks, newspapers, and Centers for Disease Control websites were also searched manually.
Discussion: To detect infested sites, avoid or limit bedbug bites, and reduce the risk of contaminating one’s belongings and home, bedbug biology and ecology must be understood. A detailed search of their most classic hiding niches is a key to finding adult bedbugs, nymphs, eggs, and feces or traces of blood from crushed bedbugs. Locally, bedbugs move by active displacement to feed (bite) during the night. Bed, mattress, sofa, and/or curtains are the most frequently infested places. If you find bedbugs, change your room or, even better, the hotel. Otherwise, travelers should follow recommendations for avoiding bedbugs and their bites during the night and apply certain simple rules to avoid infesting other sites or their home.
Conclusion: Travelers exposed to bedbugs can minimize the risks of bites and infestation of their belongings, and must also do their civic duty to avoid contributing to the subsequent contamination of other hotels and, finally, home.”
Wang, C., K. Saltzmann, E. Chin, G. W. Bennett, and T. Gibb. 2010. Characteristics of Cimex lectularius (Hemiptera: Cimicidae), infestation and dispersal in a high-rise apartment building. Journal of Economic Entomology. 103: 172–177. doi: 10.1603/EC09230
Researchers investigated bed bug infestation and dispersal, movement, in a high-rise apartment building.
Pfiester, M., P. G. Koehler, and R. M. Pereira. 2009. Effect of population structure and size on aggregation behavior of Cimex lectularius (Hemiptera: Cimicidae). Journal of Medical Entomology. 46: 1015–1020. doi: 10.1603/033.046.0506
“The bed bug, Cimex lectularius L. (Hemiptera: Cimicidae), occurs in aggregations until the conditions are no longer beneficial, leading to dispersal. Active and passive bed bug dispersal causes migrations from main aggregations either within a room, from room to room within a building, or from building to building. Because bed bug movement is an important factor in the spread of infestations, we wanted to determine how population structure and size affect bed bug aggregations. Engorged bed bugs were placed in glass petri dish arenas at varying densities, sex ratios, and population compositions. Nymphs had a high tendency to aggregate, varying between 94 and 98%, and therefore were not the likely dispersal stage of the bed bug. At densities of 10 and 40 adults at a 1:1 sex ratio, there were significantly more lone females than lone males. When the population composition was varied, the percentage of lone females was significantly higher than that of males and nymphs at population compositions of 40 and 80% adults. When the sex ratio of adults was varied, there were significantly more lone females than males in arenas with 20, 50, and 80% males. Females, being found away from aggregations significantly more often than any other life stage, are potentially the dispersal stage of the bed bug. Active female dispersal away from main aggregations can potentially lead to treatment failures and should be taken into account when using control methods.”