Bed bugs are wingless insects that have been with us for a very long time. One of the earliest mentions of this pest has been found in ancient Greece around 400 BC. They were common in the United States before World War II, but almost vanished during the 1950s because of improved hygiene and the widespread use of the pesticide DDT.
Although Bed bugs were being neutralized in the United States, they remained prevalent in other regions of the world including Central/South America, the Caribbean, Europe, Africa and Asia. With today’s globalization and the simplicity of domestic and international travel, it is very easy and common for bed bugs to hitchhike with the traveller to another location allowing them to spread and multiply throughout the world.
Infestations are increasingly being encountered in homes, apartments, hotels, motels, dormitories, shelters and some modes of transport like cruise ships. The bad news is that in recent years, bed bugs have made a comeback in the United States.
How do bed bugs spread?
In order to answer that we need to know what motivates them? The number 1 thing that makes bed bugs active is HUNGER! They exist to feed and will search for a host until one is found. A logical conclusion is that bed bugs will search out the easiest and most convenient host that can meet that need. How “clean” an environment is has very little to do with bed bug infestations. Their primary method of identifying a suitable host is through heat recognition and CO2 emissions. The good news is that the bed bug cannot detect these two elements beyond 5 feet.
The second bed bug motivator is something that we all need – a safe shelter (harborage) so they can breed and rest between blood feedings. Details on common bed bug harborages can be found in the Signs of bed bugs section of this website.
Because bed bugs and their eggs are so small and operate late at night, to early in the morning, when most people are asleep it is very easy for them to go undetected, giving the impression that they have just “magically” appeared from nowhere. Bed bugs easily escape detection by crawling into suitcases, boxes and belongings. This is a major problem for hotels, motels and apartments, where guests and occupant turnover is continuous or high and there is an abundance of warm-blooded meals.
Bed bugs live in aggregations (or communities) that offer them safe harborages, potential mates and help them resist desiccation. It is believed that they do this because the community provides benefits for the bed bugs involved that is not present when they are solitary.
Some of the possible advantages of aggregation are that they provide safe harborages from other natural bed bug predators; it can assist the adults in mate-finding as well as allow for higher resistance to desiccation (dehydration) than a solitary bed bug.
As with all good things aggregations will eventually reach a point where they are no longer beneficial to the individual bed bugs. The disadvantages are that now they become more attractive and visible to their natural predators due to larger numbers, competition becomes fiercer for food because of the overuse of resources and inbreeding becomes more prevalent. The general consensus is that when the individual bed bugs no longer benefit from the aggregation they will disperse or spread.
A common theory for bed bugs dispersing or spreading has to do with their unique mating behaviour. Bed bugs copulate through traumatic insemination.
This is a process where the male pierces the female’s abdomen (cuticle) with his genitalia (paramere) and injects sperm through the wound near the female’s reproductive tract. Because of the traumatic insemination, it is highly probable that females will leave an aggregation in order to avoid multiple inseminations.
Bed bugs can breed all year and it is typical in the Northeast when they are inside and the conditions are ideal with an ample supply of food that they can reproduce up to three generations. If the female produces two to five eggs a day an infestation can grow to a very large number in a matter of months. If left unchecked a bed bugs population can grow to the thousands in a small period of time. That is why early detection is so critical in the control of bed bugs and their infestations.
By far the most common way that bed bugs spread is by hitchhiking. It is their primary method of travel and they are extremely efficient at it. They will usually hide in or on luggage, clothing, second-hand beds & furniture where the eggs are almost impossible to see due to their small size.
Bed bugs are quick movers. An adult can crawl about 4 feet per minute and the nymphs can crawl about 1 foot per minute. Their legs are adapted for crawling and the tarsal claw at the end is used for gripping rough surfaces or their host for feeding. They can easily climb any fabric wood or paper surface by hooking the claw in and around the fibres. This design is why some of the passive bed bug traps monitors used have smooth slick surfaces on the inside. Once the bed bug falls in they are trapped because they can’t climb out.
When understanding how do bed bugs spread it is important to remember that in order for a new infestation to become established, they must first be introduced into a previously un-infested environment.
How do bed bugs spread?
The best way to prevent a bed bug infestation is through constant vigilance and early detection. If you suspect that you might have bed bugs see the articles on bed bug bites, what do bed bugs look like and how to get rid of bed bugs yourself.