Oct 23, 2023 06:51 AM
(This post was last modified: Oct 23, 2023 06:53 AM by C C.)
https://www.bbc.com/future/article/20231...-deal-with
EXCERPTS: It appears to be part of a "global resurgence" of bed bugs that has seen the creatures – small, oval-shaped insects smaller than a grain of rice – becoming a growing problem in cities around the world over the past two decades. Global travel – which has allowed the biting insects to leap continents hidden amongst the luggage of oblivious aircraft passengers – has made it easier for them to spread.
But once they gain a foothold somewhere, a recent study suggests they may also be getting harder to treat.
[...] Over the years, bed bugs have acquired three different mutations in the genes coding for sodium channels, which prevents insecticides from binding to them. We don't know exactly when the mutations developed, but they have been around since at least the 1950s, after the widespread use of DDT in World War Two.
[...] Booth and Lewis's study showed that 36% of the older bed bugs collected in the US between 2005-2009 had a single mutation in their sodium channel gene, while 50% had acquired two mutations. Just 2.5% of the population had no mutations, and were therefore susceptible to insecticides.
[...] In the more modern bedbug samples from 2018-2019, 84% of the bed bugs had acquired two mutations in their sodium channel gene, giving them total protection. Not one single bed bug from the more recent samples in the US were susceptible to insecticides.
"We saw a change in frequency of not the single mutation – the single mutation was always present – but the change in the frequency of having both mutations, so therefore that higher level of resistance," says Booth. "Pretty much every bed bug population you see nowadays has both mutations, which is really bad because you're not going to kill them. It means you can't go down to your local hardware store and buy an over-the-counter insecticide and expect that to do anything – you really need to get professional pest control."
[...] n a 2016 study, scientists at Australia's University of Sydney found evidence that bed bugs have developed a thicker exoskeleton to stop pesticides from being absorbed into their body. The higher the bed bug's resistance to pyrethroid insecticides, the thicker its outer shell, or cuticle was. Insects with a cuticle thickness of around 10 micrometres (about a tenth of the thickness of a human hair) were effectively resistant to the insecticide.
According to Booth, bed bugs are also changing their behaviour to avoid being poisoned.
[...] What, if anything, can we do to defeat the bed bug? One option is heat treatment, which involves heating up the room or entire property to a high temperature. In a study this year, researchers took 5,400 adult bed bugs from 17 infested locations in Paris. They separated them into five groups and placed each group in different tanks to simulate their natural environment. Some were allowed to set up camp amongst furniture remnants, or scraps of mattresses or blankets, while others were left uncovered in the open air. The researchers then subjected the bugs to heat. All the bugs were killed after just one hour of being heated to 60°C.
However, a 2021 study found that bed bugs have a tendency to simply flee when it gets too hot. This could be a problem, especially in multi-story apartment buildings where bed bugs could simply move out of one apartment into an unsuspecting neighbour's flat.
Heating your house is also not something you should try at home. "Don't ever try to use heat yourself," says Booth. "I've heard stories of people going to get propane heaters and setting their house on fire. It just doesn't work. You're more likely to kill yourself then do harm to the bed bugs."
[...] "Are bed bugs infestations suddenly erupting across France and London, or have they simply gone unreported?" says Booth. "I think it's the latter. They have always been there, but simply gone relatively unnoticed. They are incredibly cryptic, and as such, many infestations at low levels will go unnoticed." (MORE - missing details)
EXCERPTS: It appears to be part of a "global resurgence" of bed bugs that has seen the creatures – small, oval-shaped insects smaller than a grain of rice – becoming a growing problem in cities around the world over the past two decades. Global travel – which has allowed the biting insects to leap continents hidden amongst the luggage of oblivious aircraft passengers – has made it easier for them to spread.
But once they gain a foothold somewhere, a recent study suggests they may also be getting harder to treat.
[...] Over the years, bed bugs have acquired three different mutations in the genes coding for sodium channels, which prevents insecticides from binding to them. We don't know exactly when the mutations developed, but they have been around since at least the 1950s, after the widespread use of DDT in World War Two.
[...] Booth and Lewis's study showed that 36% of the older bed bugs collected in the US between 2005-2009 had a single mutation in their sodium channel gene, while 50% had acquired two mutations. Just 2.5% of the population had no mutations, and were therefore susceptible to insecticides.
[...] In the more modern bedbug samples from 2018-2019, 84% of the bed bugs had acquired two mutations in their sodium channel gene, giving them total protection. Not one single bed bug from the more recent samples in the US were susceptible to insecticides.
"We saw a change in frequency of not the single mutation – the single mutation was always present – but the change in the frequency of having both mutations, so therefore that higher level of resistance," says Booth. "Pretty much every bed bug population you see nowadays has both mutations, which is really bad because you're not going to kill them. It means you can't go down to your local hardware store and buy an over-the-counter insecticide and expect that to do anything – you really need to get professional pest control."
[...] n a 2016 study, scientists at Australia's University of Sydney found evidence that bed bugs have developed a thicker exoskeleton to stop pesticides from being absorbed into their body. The higher the bed bug's resistance to pyrethroid insecticides, the thicker its outer shell, or cuticle was. Insects with a cuticle thickness of around 10 micrometres (about a tenth of the thickness of a human hair) were effectively resistant to the insecticide.
According to Booth, bed bugs are also changing their behaviour to avoid being poisoned.
[...] What, if anything, can we do to defeat the bed bug? One option is heat treatment, which involves heating up the room or entire property to a high temperature. In a study this year, researchers took 5,400 adult bed bugs from 17 infested locations in Paris. They separated them into five groups and placed each group in different tanks to simulate their natural environment. Some were allowed to set up camp amongst furniture remnants, or scraps of mattresses or blankets, while others were left uncovered in the open air. The researchers then subjected the bugs to heat. All the bugs were killed after just one hour of being heated to 60°C.
However, a 2021 study found that bed bugs have a tendency to simply flee when it gets too hot. This could be a problem, especially in multi-story apartment buildings where bed bugs could simply move out of one apartment into an unsuspecting neighbour's flat.
Heating your house is also not something you should try at home. "Don't ever try to use heat yourself," says Booth. "I've heard stories of people going to get propane heaters and setting their house on fire. It just doesn't work. You're more likely to kill yourself then do harm to the bed bugs."
[...] "Are bed bugs infestations suddenly erupting across France and London, or have they simply gone unreported?" says Booth. "I think it's the latter. They have always been there, but simply gone relatively unnoticed. They are incredibly cryptic, and as such, many infestations at low levels will go unnoticed." (MORE - missing details)
