The ability of bed bugs to develop pesticide resistance and spread through travel has turned them into a persistent problem for authorities in Paris.
Videos are flooding social media and news outlets showing bed bugs crawling through every nook and cranny of Paris, from subway seats to recliners in movie theaters. This insect is raising concerns across Paris and around the world due to the influx of tourists to the city who may return home with these bloodsucking pests. “No one is safe,” emphasized the Deputy Mayor of Paris on Twitter during Paris Fashion Week.
Bed bugs nesting in fabric and padding of furniture. (Photo: Guardian)
Although bed bugs can be considered a nuisance, they do not spread disease and typically cause itchy discomfort rather than posing a serious health threat. Bed bugs were nearly eradicated from the 1940s until the late 1990s due to the use of pesticides, but they have re-emerged in recent years, surging in nearly every major city, including New York and Hong Kong. The situation in Paris may not yet be classified as an outbreak, but it serves as evidence of a long-standing issue and an example of the effective survival capabilities of bed bugs, according to National Geographic.
Anyone who has encountered bed bugs in their home knows that their bites can cause itchy, swollen discomfort. Eradicating bed bugs is also extremely difficult because they nest within the fabric and padding of furniture. A bed bug typically lives only a few months or up to a year in some cases. However, that is long enough for a population to explode, according to Zachary DeVries, an urban entomologist at the University of Kentucky. “You can let one female bed bug out of your house. It will mate and quickly start a population that grows out of control in just a few weeks or months,” DeVries stated.
Bed bugs belong to the family Cimicidae, which includes about 100 species of small parasitic insects that feed on warm-blooded animals. Only three species commonly bite humans, with Cimex lectularius being the most prevalent. Adult bed bugs are reddish-brown, wingless, and approximately 0.6 cm long, about the size of an apple seed. They are often confused with other bloodsucking pests like fleas, but can be distinguished by their flattened, oval bodies.
Bed bugs have been an issue since humans began recording history, DeVries notes. Traces of them have been found in Egyptian tombs dating back over 3,500 years. But where did they first come from? Scientists are uncertain about the bed bug’s oldest ancestors, but a leading hypothesis regarding the emergence of modern bed bugs is that they evolved alongside bats. “200,000 years ago, when humans lived in caves with bats, a species of bed bug took a liking to them,” said Coby Schal, an entomologist at North Carolina State University. “When humans left the caves, that species of bed bug followed them.”
Once a bed bug finds a target, it inserts a straw-like tube attached to its head into the skin to suck warm blood. They also inject a cocktail of proteins during the bite, including anesthetics and anticoagulants. Although they do not carry diseases, bed bug saliva can cause allergic reactions in some individuals, resulting in large, itchy welts. Others may not even realize they are living with bed bugs because their skin does not react, according to Schal.
Through a tactic called traumatic insemination, mature male bed bugs insert a curved penis into the female’s abdomen and directly pump sperm into her body. The sperm then travels through the female’s circulatory system to the uterus, where it fertilizes the eggs. According to William Hentley, an ecologist at the University of Sheffield in the UK, how they evolved this reproductive mechanism remains a mystery.
Over time, female bed bugs have evolved a specialized organ in their abdomen called a spermalege that contains immune cells to help prevent infection at the wound site. After the violent mating, females typically lay 1 to 7 eggs per day, which hatch into nymphs. Nymphs go through 5 stages of development before reaching maturity, although they must feed on blood to complete each molting phase.
Historically, humans have sought various ways to control bed bug outbreaks. One of the most successful efforts occurred during World War II when the pesticide DDT, which is now banned, was widely distributed to eliminate bed bugs. This chemical was initially very effective in controlling them. However, by the 1990s, a new population of bed bugs resistant to DDT began to spread.
The problem has worsened as global travel has increased in recent decades, allowing these bloodsucking pests to spread worldwide and seek new hosts every day. As a result, bed bug populations have thrived, and many individuals have developed resistance to available pesticides. Pest control experts often rely on heat treatments since bed bugs will die if exposed to temperatures of 43.3 degrees Celsius (110 degrees Fahrenheit) for at least 90 minutes.
