A new harder-to-kill species of bed bug is invading the US, experts say — and may already have taken up residence in many northern cities.
Once confined to countries near the equator, the species known as Cimex hemipterus — or the tropical bed bug — has already been confirmed in Florida and Hawaii.
Unlike the common bed bug, the blood-sucking insect is resistant to virtually all insecticides — likely thanks to their rampant overuse against mosquitoes.
Its body composition means it is also able to evade traps like smooth-walled pitfall traps, which are set up underneath bed legs to catch the critters.
It comes as outbreaks of the pest are rising in as many as 50 countries. Across the US, the cities experiencing the most outbreaks are in the Mid-West.
Chicago, New York and Philadelphia residents should inspect their mattresses as experts report their cities ranked first, second and third for bed bugs in 2023. The new findings were built off economic data from both residential and commercial bed bug treatments
Bedbugs are not disease carriers, but being bitten by one causes itchy red welts on the skin similar to poison ivy
Entomologists at the University of California, Riverside, revealed the worrying spread of the blood-sucking critter in an article published in the Annual Review of Entomology.
While nearly all cases were restricted to deprived areas of Africa and Asia after the mass use of insecticides nearly eradicated them in the wake of the Second World War, the insects have now ‘resurged’ and spread back into parts of Europe and America.
Researchers say the tropical bedbug was spotted in Florida in 2016 for the first time in 60 years, and then in Hawaii — where it was reported in 2020.
Researchers fear, however, that heating and air con — keeping buildings at constant temperatures year-round — and the sudden return to pre-pandemic travel and more people traveling may have fueled the spread alongside resistance to insecticides.
Cases of the insects being detected as far north as Russia and Norway suggest they are now able to survive in colder areas, they said.
There are also fears that the pest could carry and transmit more harmful diseases between humans, possibly including hepatitis.
The scientists, including Dr Chow-Yang Lee, from the University of California, Riverside, said: ‘Most bed bug control products were developed for [the common bed bug], with the assumption that they would also work on [the tropical bed bug].
‘However, biological differences between the species are being discovered that have implications for the management of [the tropical bed bug].
‘A recent study demonstrated that [the tropical bed bug] readily escapes from pitfall traps that contain [the common bed bug], as the species has more hairs on its [legs], giving it more grip and enabling it to climb smooth surfaces.
Natalie Brown (pictured), 28, was left covered in bedbug bites after she spent three days on a vacation in Benidorm, Spain
The insets hide in mattress fabric and crevices before emerging at night to bite their sleeping victims. The bugs can also hide in clothing, furniture, and even books
‘In contrast to [the common bed bug], which has several standard susceptible strains [to insecticides], no insecticide-susceptible strain of [the tropical bed bug] exists.
‘Similarly, it is not known if [the tropical bed bug] produces different health impacts, perhaps due to the existence of different antigenic compounds in the saliva.’
Warnings over bed bugs were sparked in London late last year after one caused panic when it was spotted on the subway.
There were also concerns over outbreaks in France, after A-listers attending Fashion Week — including Gigi Hadid and Paris Hilton — reported seeing the insects at events.
It was not clear whether these outbreaks were caused by the tropical kind.
Bed bugs appeared to have been consigned to the history books in the 1940s thanks to powerful pesticides such as DDT which killed them instantly.
But amid overuse of many chemicals, the insects have gained genetic mutations which make them resistant — such as developing the ability to rapidly break down the toxins.
They have also grown thicker exoskeletons which the chemicals are less likely to penetrate and kill the insects.
This has allowed the insects to once again spread across the world largely unnoticed, thanks to many now not being used to the critters.
Warning signs of an infestation include inflamed spots, which are often darker in the middle, and are located on the face, neck, arms or hands.
Experts say they will be arranged in a rough line — highlighting where the insect has sucked blood — and cause a serious itch.
To detect an infestation, patients are advised to search their bedding for rusty or reddish stains — signs of crushed bed bugs — or small black dots — which are their feces.
Infestations are notoriously difficult to treat, with many experts now no longer using chemicals because they just don’t work.
Instead, strategies include heating rooms to 120F (48C) to kill the insects, and hoovering in cracks and crevices such as plugs.
It can take up to a month to eliminate an infestation, experts warn, because the insects are adept at avoiding being killed.
Chicago, New York City and Philadelphia have recently been named as the bed bug capitals in the United States.
Researchers at pest control giant Orkin looked at the number of bed bug treatments they issued across 50 major US cities to come up with the figures.
They also pointed to Greensboro, North Carolina, as being a center with an emerging outbreak — after the city jumped 25 places within a year, to enter the top 20 bed bug hotspots.
Milwaukee, Wisconsin also jumped 15 places to number 25 on the list while Tampa, in Florida, went up by 10 to the 31st spot.
In New York City, data shows about 440 outbreaks were reported in 2020, the latest year available. This is equivalent to 14 complaints a day, but down on the figure from 2014 when there were 875 complaints recorded.