Problems caused by bed bugs

Global increase of bed bugs

Since the 1990s, there has been a worldwide outbreak of bed bugs. In New York, for example, 15% of homes are affected and the number of reported complaints is constantly rising: 34,000 complaints in 2009, compared to just 537 in 2004. In France and Belgium, it is still a taboo topic and no precise figures are available. However, in 2000, only 1 case of bed bugs was reported per month, whereas nowadays, several are reported every week. The huge plague of this pest may be due to the fact that the bugs have grown resistant to most insecticides, such as DDT, which almost wiped it out completely in the 1960s. The increased amount of travel and migrations have also played a role in their spread through cities. Bugs actually find it very easy to move around via our luggage.

What nuisances do they cause?

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Bed bugs are haematophagous insects, which means that they feed on blood. Their favourite hosts are humans. They are very harmful and their bites cause skin rashes and allergies. In the event of a severe infestation, a human may be bitten 500 times in one night, which may even cause anaemia; this is a more serious risk among toddlers. Bed bugs are not vectors for diseases between humans, but bed bug infestations can be a source of anxiety, and can even cause deep psychosocial mental distress. The presence of bed bugs also reduces a person's quality of sleep and can lead to social isolation. Bed bugs are also responsible for the indirect health repercussions engendered by the intense usage of insecticides.  

What are bed bugs?

Classification

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Bed bugs are haematophagous insects (feed on blood) belonging to the Hemiptera order and the Cimicidae family. The main species responsible for biting humans are Cimex lectularius and Cimex hemipterus. Cimex lectularius are normally found in temperate climates, whereas Cimex hemipterus live in tropical regions.

Life cycle

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Bed bugs reproduce by traumatic insemination: the male’s hypodermic penis pierces through the female's abdomen. After fertilisation, the female lays 5 to 10 eggs, which she deposits in a cluster. A female can lay between 200 to 500 eggs in a lifetime. Newly hatched bugs, called nymphs, go through 5 development stages before becoming adults. A blood meal is required before maturing and reaching the final stage. Nymphs are transparent yellow in colour. Once they reach their adult stage, bed bugs turn brown and measure between 4 - 7mm (size of an apple seed), so they are clearly visible to the naked eye. Bed bugs normally feed every 3 to 7 days, but can survive several months without eating.

Where do they hide?

Bed bugs hide near their host, the human, in places where the latter goes to rest; in other words, near beds and sofas. Due to this insect’s flat shape, they can hide in any crack wide enough for a credit card. Bed bugs can therefore settle in a huge number of hiding places, such as behind skirting boards and headboards, along the seams of mattresses and bed sheets, in bed bases, in the tiniest cracks of a wall or wardrobe, etc. Most of the time, bed bugs, which are gregarious and photophobic (flee from light), remain hidden in their places of refuge and only come out when they need to feed, mainly at night. They are therefore difficult to spot. Even if you are not able to see a living individual, it is still possible to detect certain signs of their presence: black stains on a mattress and bed base (bed bug excrement), blood stains on the sheets, moulting residue, eggs or dead bugs. Canine detection may also be used to identify early infestations.

Where can you find them?

Places with a high turnover of occupants are the worst affected by bed bug problems. Many hotels are having to deal with this plague. Flats and houses are also heavily affected. However, bed bugs can also be found in public places, such as cinemas, public transport (planes, sleeper trains,...), libraries, clothes shops, etc.

Current solutions

Eliminating these domestic pests is an arduous, expensive and difficult task using current techniques. In fact, these insects often hide in inaccessible places. Furthermore, they are resistant to most insecticides and can even survive for several months without feeding. Once an infestation of this pest has been formally identified, there are two possible control methods that can be used; mechanical and chemical. The two techniques can also complement each other.

Mechanical control method

The use of mechanical control (without using insecticides) is strongly advised, and even considered essential in order to reduce and remove the parasite load from a location as much as possible. The main advantage of this being that it does not encourage the bugs to form a resistance.

  • Vacuuming: using the narrow tip of the vacuum cleaner to remove visible eggs, juveniles and adults. The vacuum cleaner does not kill this insect, so it can still escape. The vacuum cleaner pipe should be cleaned and the bag should be sealed or wrapped up in a plastic bag and thrown into an outside bin to avoid any further contamination.

  • Freezing at -20°C: for at least 48 hours, depending on the size of the object.

  • Washing in a washing machine or tumble-drying: at a temperature greater than 55°C.

  • Steam cleaning: at 120°C, all bed bugs at all stages of development living in tiny corners or furniture upholstery will be destroyed.

  • Brush cleaning: dry brushing certain tiny corners or fabrics with a surface cleaner is a supplementary measure for removing eggs and poorly visible juvenile bugs. Brushing does not kill the insect and should be used in addition to vacuuming or thoroughly cleaning the floor.

  • Property restoration: loose wall paper, paint, plaster, skirting boards, carpets and wall cracks are ideal resting and breeding sites for bed bugs. Restoring one’s home and re-fitting skirting boards or door casings helps remove all these sites.

  • Removing upholstery: be sure that the fabric is immediately discarded without being recovered or stored elsewhere before complete destruction.

  • Heating furniture: for any object able to withstand temperatures equal to or greater than 60°C. This temperature will kill all bugs at all development stages.

  • Mattress and bed base covers: covers that trap bugs and prevent others from settling there. Mattresses and bed bases are a bed bug's favourite hiding place.

Chemical methods

For most infestations, the site should be treated by a professional. They should treat the area at least twice, with a two-week interval. The second intervention will kill any young offspring that have hatched from eggs that were resistant to the insecticide or adults that evaded the first treatment.

Bed bug traps

The traps that are currently available on the market only work well as detectors of infestations. They do not actually help eradicate an infestation. 

Our solution

We are currently studying the social environment these insects live in and the way they communicate. Our aim is to find ways of attracting them and eliminating them without the use of toxic products, much like the method we used to develop Acar’up.

These lure traps will provide an appealing alternative to insecticides. 

Did you know?

Bed bugs are not synonymous with poor hygiene! They can be found in clean places too. Some luxury hotels have even had problems with infestations of this pest. However, lower social classes are more commonly affected by bed bugs. Some people may even unknowingly take in bed bug-infested furniture from the street. Furthermore, bed bug treatments are extremely expensive and some people simply do not have the means to treat their homes.

Bed bugs have existed for thousands of years. They used to act as parasites on bats. When humans started inhabiting caves, bed bugs started feeding on humans and became human ectoparasites. When humans started leaving the caves, these tiny creatures left with them. The bed bug’s love for humans is therefore age-old. References to these insects can even be found in Ancient Greek and Roman literature.  

Contact

manhattan

Do you have any questions about this project? Would you like to know more about bed bugs? Please contact the researcher in charge of this project, Manhattan Solheid at the following email address This email address is being protected from spambots. You need JavaScript enabled to view it. or by telephone +32 (0) 2 880 62 67.   

Link to find out more about pests of all kinds

www.acari.be