Bed bugs, or
cimicidae, are small
parasitic insects. The term usually refers to species that prefer to feed on human blood.
Early detection and treatment are critical to successful control.
According to a survey, the most commonly infested places are the
mattress (98.2%), boxspring (93.6%), as well as nearby carpets and
baseboards (94.1%).
In fact, bed bugs thrive in areas where there is an adequate supply of
available hosts, and plenty of cracks and harborages within 1.5 metres
(4.9 ft) of the host.
Because treatments are required in sleeping areas and other sensitive locations, methods other than chemical
pesticides are in demand. Treatments can be costly, laborious, time consuming, repetitive, may entail
health risks, and cause embarrassment to the person affected.
Public health
Bed bug infestations spread easily in connecting units and have
negative effects on psychological well-being and housing markets. In
response, many areas have specific laws about responsibilities upon
discovering a bed bug infestation, particularly in hotels and
multi-family housing units, because an unprofessional level of response
can have the effect of prolonging the invisible part of the infestation
and spreading it to nearby units. Common laws include responsibilities
such as the following:
Lessors
must educate all lessees about bedbugs, lessee must immediately notify
lessor in writing upon discovery of infestation, lessor must not
intentionally lease infested unit, lessee must not intentionally
introduce infested items, lessor must eradicate the infestation
immediately every time it occurs at a professional level including all
connecting units, and lessee must cooperate in the eradication process.
An example of how epidemic bed bug infestation can become in densely populated areas is the
Bed Bug Registry.
Mapped bed bug reports graphically illustrate how difficult it can be
to eliminate bed bugs where many people live in adjacent units like in
New York City, Los Angeles, and San Francisco.
Pesticides
Though commonly used, the
pesticide
approach often requires multiple visits and may not always be effective
due to pesticide resistance and dispersal of the bed bugs. According to
a 2005 survey, only 6.1% of companies claim to be able to eliminate bed
bugs in a single visit, while 62.6% claim to be able to control a
problem in 2–3 visits. Insecticide application may cause dispersal of bed bugs to neighbouring
areas of a structure, spreading the infestation. Furthermore, the
problem of
insecticide resistance
in bed bug populations increases their opportunity to spread. Studies
of bed bug populations across the United States indicate that resistance
to
pyrethroid insecticides, which are used in the majority of bed bugs cases, is widespread.
Exterminators
often require individuals to dispose of furniture and other infested
materials. It is advisable to break or mark these infested items to
prevent their being unintentionally recycled and furthering the spread
of bed bugs.
Effectiveness
The well-established resistance of bed bugs to DDT and pyrethroids
has created a need for different and newer chemical approaches to the
extermination of bed bugs. In 2008 a study was conducted on bed bug
resistance to a variety of both old and new insecticides, with the
following results, listed in order from most- to least-effective:
λ-cyhalothrin,
bifenthrin,
carbaryl,
imidacloprid,
fipronil,
permethrin,
diazinon,
spinosyn,
dichlorvos,
chlorfenapyr,and
DDT.
[4]
Note that the first of these, λ-cyhalothrin, is itself a
pyrethroid-based insecticide— in the past, however, it has been used
principally for the treatment of cotton crops and so bed bugs have not
developed a genetic resistance to it.
Disadvantages
Non-residue methods of mattress treatment are desired in place of
contaminating mattresses with insecticides. Furthermore, other methods
such as
vacuuming
must often be used in conjunction with pesticides to fully eradicate
bed bugs. Spraying the mattress with insecticide is undesirable as the
room must be suitably ventilated, sufficient time must be given after
application before the mattress can be used again and there is a risk of
the user having an
allergic reaction to the chemicals, not to mention other possible health risks including cancer and acute neurotoxicity.
Concerns over the possible
health effects of pesticides
on people and pets, as well as the dispersal of bed bugs to
neighbouring dwellings due to repellent effects of insecticides, make
the practice of chemically treating the mattresses problematic.
Resistance
Bed bugs are developing resistance to various
pesticides including
DDT and
organophosphates.
Some populations have developed a resistance to
pyrethroid
insecticides. Although now often ineffective, the resistance to
pyrethroid allows for new chemicals that work in different ways to be
investigated, so chemical management can continue to be one part in the
resolving of bed bug infestations.
There is growing interest in both synthetic pyrethroid and the pyrrole
insecticide, chlorfenapyr. Insect growth regulators, such as hydroprene
(Gentrol), are also sometimes used.
Populations in Arkansas have been found to be highly resistant to DDT, with an LD
50 of more than 100,000 ppm.
DDT was seen to make bed bugs more active in studies conducted in Africa.
Bed bug pesticide-resistance appears to be increasing dramatically.
Bed bug populations sampled across the U.S. showed a tolerance for
pyrethroids several thousands of times greater than laboratory bed bugs.
New York City bed bugs have been found to be 264 times more resistant to
deltamethrin than Florida bed bugs due to mutations and evolution.
A
population genetics study of bed bugs in the United States, Canada, and Australia using a
mitochondrial DNA marker found high levels of genetic variation. This suggests the studied 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 genetic
variation observed with the mitochondrial DNA marker, no genetic
variation in a nuclear RNA marker was observed. This suggests increased
gene flow of previously isolated bed bug populations, and given the absence of barriers to gene flow, the spread of
insecticide resistance may be rapid.
Physical isolation
Isolation of humans is attempted with numerous devices and methods
including zippered bed bug-proof mattress covers, bed-leg moat devices,
and other barriers. However, even with isolated beds, bed bug
infestations persist if the bed itself is not free of bed bugs, or if it
is re-infested, which could happen quite easily.
Inorganic materials
Inorganic materials such as
diatomaceous earth
may be used in conjunction with other methods to manage a bed bug
infestation, provided they are used in a dry environment. Upon contact
with such dust-like materials, the insect's waxy outer layer of their
exoskeletons is disrupted, which causes them to dehydrate.
Although occasionally applied as a safe indoor pesticide treatment for other insects,
boric acid is ineffectual against bed bugs because bed bugs do not groom.
Organic materials
Bean leaves
A traditional
Balkan method of trapping bed bugs is to spread bean leaves in infested areas. The
trichomes (microscopic hooked hairs) on the leaves trap the bugs by piercing the
tarsi joints of the bed bug's
arthropod legs.
As a bug struggles to get free, it impales itself further on the bean
leaf's trichomes. The bed bugs and leaves then can be collected and
destroyed. Researchers are examining ways to reproduce this capability with artificial materials.
Essential oils
Many claims have been made about essential oils killing bed bugs.
However, they are unproven. The FTC is now filing a suit against
companies making these claims.
Contaminated belongings
Disposal of items from the contaminated area can reduce the
population of bed bugs and unhatched eggs. Removal of items such as
mattresses, box springs, couches etc. is costly and usually insufficient
to eradicate infestation because of eggs and adults hiding in
surrounding areas. If the entire infestation is not eliminated prior to
bringing new or cleaned personal and household items back into a home,
these items will likely become infested and require additional
treatment. Treating clothing, shoes, linens, and other household items
within the affected environment is difficult and frequently ineffective
because of the difficulty of keeping cleaned items quarantined from
infestation. Many bed bug exterminating specialists recommend removing
personal and household items from the infested structure. Many
metropolitan areas offer more effective treatments such as high-heat
dryers and dry cleaning with PERC with the added benefit of the treated
items remaining stored until the affected home's bed bug infestation is
eradicated
The improper disposal of infested furniture also facilitates the
spread of bed bugs. Marking the discarded items as infested can help
prevent infesting new areas. Items may also be sealed in plastic and
stored until all eggs hatch and all larvae and adults have died.
Bed bugs can go without feeding for 20 to 400 days, depending on
temperature and humidity. Older stages of nymphs can survive longer
without feeding than younger ones, and adults have survived without food
for more than 400 days in the laboratory at low temperatures. Adults
may live up to one year or more, and there can be up to four successive
generations per year.
Vacuuming
Vacuuming
helps with reducing bed bug infestations, but does not eliminate bed
bugs hidden inside of materials. Also, unless the contents of the vacuum
are emptied immediately after each use, bedbugs may crawl out through
the vacuum's hoses and re-establish themselves.
Heat treatment
Steam
Steam
treatment can effectively kill all stages of bed bugs. To be effective,
steam treatment must reach 150–170 degrees for a sustained period.
Unfortunately, bed bugs hide in a diversity of places, making steam
treatment very tedious, labour-intensive and time consuming. There is
also the risk of the steam not penetrating materials enough to kill
hidden bed bugs. The steam may also damage materials such as varnished
wood, or cause mold from the moisture left behind. Effective treatment
requires repeated and very thorough steaming of the mattress, box
spring, bed frame, bed covers, pillows, not to mention other materials
and objects within the infested room, such as carpets and curtains.
Clothes dryers
Clothes dryers
can be used for killing bed bugs in clothing and blankets. Infested
clothes and bedding is first washed in hot water with laundry detergent
then placed in the dryer for at least 20 minutes at high heat.
However, this does not eliminate bed bugs in the mattress, bed frame
and surrounding environment. Sterilized fabrics from the dryer are thus
easily re-infested. Continually treating materials in this fashion is
labour-intensive, and in itself does not eliminate the infestation.
Hot boxes
Placing belongings in a hot box, a device that provides sustained
heat at temperatures that kills bedbugs, larvae, and eggs, but that does
not damage clothing, is an option. Pest control companies often rent
the devices at nominal cost and it may make sense for frequent travelers
to invest in one.
Building heat treatment
This method of bed bug control involves raising
room temperatures to or above the killing temperature for bed bugs, which is around 45 °C (113 °F).
Heat treatments are generally carried out by professionals, and may be
performed in a single area or an entire building. Heat treatment is
generally considered to be the best method of eradication because it is
capable of destroying an entire infestation with a single treatment.
For safety reasons, it is important that HEPA air filtration is used
by your professional during any heat treatment to capture particulate
and biological matter that may be aerosolized during the heating
process.
Freezing
Many claims exist about the effectiveness of freezing Bedbugs. They
vary from freezing works, it only works in extremely low temperatures,
to it doesn't work at all. The theory is, in areas where outdoor
temperatures drop below freezing, mattresses, couches, and other
furniture can be placed outside for 24 hours allowing the bedbugs to
freeze.
Fungus
Preliminary research has shown the fungus
Beauveria bassiana, which has been used for years as an outdoor organic pesticide, is also highly effective at eliminating
bed bugs
exposed to cotton fabric sprayed with fungus spores. It is also
effective against bed bug colonies due to the spores carried by infected
bugs back to their harborages. Unlike typical insecticides, exposure to
the fungus does not kill instantly, but all subjects died within 5 days
of exposure. Some people, especially those with compromised immune
systems, may react negatively to the concentrated presence of the fungus
directly following an application.
Drugs
Early research shows that the common drug taken to get rid of
parasitic worms,
Ivermectin
(Stromectol), also kills bed bugs when taken by humans at normal doses.
The drug enters the human bloodstream and if the bedbugs bite during
that time, the bedbug will die in a few days. Stromectol is also
effective against
mosquitoes, which can be useful controlling
malaria.
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