A new, highly resistant species of bed bug is spreading across the United States, and experts fear it may already have taken hold in several northern cities. The species, known as Cimex hemipterus, or the tropical bed bug, was once confined to regions near the equator. However, it has now been confirmed in Florida and Hawaii, with concerns that it is rapidly expanding its range.
Unlike common bed bugs, this tropical variant is resistant to nearly all insecticides—a resistance believed to have developed due to the widespread use of chemicals against mosquitoes. Additionally, its body structure enables it to evade standard bed bug traps, such as smooth-walled pitfall traps placed under bed legs.
This alarming development comes amid a global resurgence of bed bug outbreaks, affecting up to 50 countries. In the U.S., the highest concentration of cases is occurring in Midwestern cities. Researchers from the University of California, Riverside, highlighted the species’ concerning spread in a recent Annual Review of Entomology article.
Following near-eradication in the post-World War II era due to widespread insecticide use, bed bug populations were largely restricted to impoverished areas of Africa and Asia. However, in recent years, they have resurged in Europe and North America. Scientists first spotted the tropical bed bug in Florida in 2016—the first U.S. sighting in 60 years—and then again in Hawaii in 2020.
Experts believe several factors are fueling their spread, including climate-controlled buildings that maintain ideal temperatures year-round, increased post-pandemic travel, and the species’ growing resistance to insecticides. Reports of infestations as far north as Russia and Norway suggest that the tropical bed bug is now capable of surviving in colder climates.
Adding to concerns, researchers warn that these pests might be capable of transmitting diseases, including hepatitis. Dr. Chow-Yang Lee, an entomologist at the University of California, Riverside, explained:
“Most bed bug control products were developed for the common bed bug, assuming they would also be effective against the tropical bed bug. However, biological differences between the species impact their management.”
Studies have shown that tropical bed bugs can easily escape standard pitfall traps due to the increased number of hairs on their legs, which provide extra grip and allow them to climb smooth surfaces. Unlike common bed bugs, no insecticide-susceptible strain of the tropical species has been identified. Additionally, it remains unclear whether their bites produce different health effects due to variations in their saliva composition.
Concerns over bed bugs have already made headlines in major European cities. In late 2023, panic erupted in London when a bed bug was spotted on the subway. A similar outbreak in France during Paris Fashion Week caused alarm among A-list attendees, including Gigi Hadid and Paris Hilton. However, it remains uncertain whether these infestations involved the tropical species.
Historically, bed bugs were nearly eradicated in the 1940s with powerful pesticides such as DDT. However, overuse of chemicals has led to genetic mutations, making modern bed bugs highly resistant. They have evolved to break down toxins quickly and developed thicker exoskeletons that prevent chemicals from penetrating. As a result, infestations have become more common, often going unnoticed due to the public’s lack of familiarity with these pests.
Source: Daily Mail
