Despite dousing the mattress with extra-strong insect killer, waking up with red bites can leave anyone scratching their head.

Bed bugs were once easy targets for pesticides, but now even the most potent chemicals are nothing but squirt guns against them.

Over time, these pesky critters have turned into some of the most hardened insects on the planet. Keep reading to find out how bed bugs evolved and became resistant to insecticides.

bed bug

Are Bed Bugs Resistant to Pesticides?

The widespread use of the now-banned DDT nearly wiped out bed bugs from UK homes in the past. However, some populations survived and developed resistance, and they’re back with a vengeance.

Many studies have confirmed the alarming extent of pesticide resistance among Cimex Lectularius, or the common bed bug.

These findings highlight the stark reality of this decades-long pest problem in the United Kingdom. Five of 10 different bed bug populations displayed reduced bifenthrin tolerance, and three showed lower susceptibility to chlorfenapyr.

Darwin’s students will agree – Nature has chosen, and the strongest creepers remain with the ability to withstand high doses of toxins.

What Is Bed Bug Pesticide Resistance?

Bed bug pesticide resistance refers to the ability of bed bugs to survive exposure to pesticides that were once highly effective in exterminating them.

Two classes of insecticides are commonly used to control bed bugs, but these pests are building up tolerance against them.

  • Pyrethroids: Pyrethroids bind with sodium pores in the nerve cells, causing them to fire endlessly until the insect gets paralyzed and dies. Some pyrethroid-based insecticides that bed bugs are increasingly resistant to are Bifenthrin, Chlorfenapyr, Permethrin, and Deltamethrin.
  • Neonicotinoids: Neonicotinoids, or Neonics, attack the bug’s central nervous system. Like pyrethroids, they attach to specific receptors in bed bugs and cause paralysis and death.

How Did Bed Bugs Evolve and Become Resistant to Pesticides?

Bed bugs randomly develop mutations when they find themselves in, let’s say, a bed that has been sprayed with pyrethroids.

If a bug carries the resistance mutation, it has a better chance of surviving and reproducing, passing the mutation on to its offspring. Fast forward a few generations, and you’ve got bedfellows practically invincible against pesticides.

The bed bug’s evolutionary history has primed them for insecticide resistance. Resistance mutations were initially rare, but they became much more common with the widespread use of DDT in the 1950s and 60s.

DDT and pyrethroids both target the sodium pores in nerve cells. While DDT may be out of the picture, bed bugs still possess these mutations that protect them against it. The same mutations that protect bed bugs from DDT also safeguard them from pyrethroids.

Consequently, pyrethroid exposure gave bed bugs the genetic variation necessary to survive the newer neonicotinoids. In a nutshell, natural selection favoured past mutations, which continue to persist in modern bed bug populations.

Bed Bug Adaptations That Make Them Resistant to Insecticides

Over time, bed bugs have developed adaptations to evade insecticides, which has led to the resurgence of superbug colonies. As part of their evolution, bed bugs were able to combine fragments of their genes for a two-fold defence against pesticides.

  • Thicker Exoskeleton: Researchers found 14 DNA markers in bed bugs that affect the thickness of their outer shells. They can prevent toxic chemicals from penetrating their vulnerable inner bodies with thicker armour.
  • Metabolic Resistance: Bed bugs have developed mutations in the pores or sodium channels in the neuron’s outer membrane. Biologists found changes in two of 2000 amino acids in parts of the sodium pore. As a result, they have become insensitive and no longer respond to the toxic effects of insecticides.On top of mutations in their nerve endings, bed bugs produce a cocktail of detoxifying enzymes to break down toxic substances in chemical treatments. Together, they form a one-two punch against insecticides.

Final Thoughts

How bed bugs evolved and became resistant to insecticides is simply Darwinism working. Thanks to our over-reliance on excessive amounts of bug spray, even the strongest ones have lost their sting.

Insecticides have become less efficient in combating bed bugs but still, there is a good alternative that does not require the use of chemical pesticides, and it is 100% effective at eliminating bed bugs.

Heat treatment for bed bugs is generally considered to be one of the most effective ways to eliminate bed bug infestations. This method involves using specialised equipment to raise the temperature in a room or building to a level that is lethal to bed bugs and their eggs. Heat treatment is also typically faster than other methods, with most treatments being completed in a single day.

So, consider fresh and inventive ways of pest management, and don’t let the bed bugs bite!