Scientists decode bed bug genome as pesticide resistance results in a resurgence

bedbug mattress or street art
CC BY 2.0 Marta Kat

Recent reports highlight the growing pesticide resistance of bed bugs, a plague that was almost wiped out half a century ago, but which has crept back across the globe thanks to increased travel and exchange of pre-owned items.

Just in time, then, scientists have decoded the bed bug genome. The results of the corroboration of dozens of scientists around the world are published in a recent paper in Nature Communications.

For the most part, bed bug bites are harmless -- except for the itching. And that insomnia-inducing sense that little monsters come out when the lights are off. There is evidence that bed bug bites can carry antibiotic resistant Staphylococcus aureus (MRSA) and American trypanosomes, a parasite related to Chagas disease, but scientists report that "no evidence exists of disease transmission by bed bugs in the field." Scientists will be looking at the genome and other bed bug characteristics to determine why they do not spread disease.

Bed bugs reproduce prolifically -- but in a strange and violent manner. The male bed bug pierces the abdomen of the female in what scientists call "traumatic insemination." This method of reproduction exists in various apparently unrelated groups, so better genetic data may underpin an understanding of how this behavior evolved.

Scientists could see the genes that make bed bugs so effective: their ability to fit in small crevices, sense the location of their next meal (they live only on fresh blood), and evolution of a biting proboscis through which a small amount of anasthetic is injected to allow the parasites to feed without alerting their host all have fingerprints in the bed bug genome.

Perhaps most disturbingly, the scientists found a buildup of resistance to a broad range of pesticides, suggesting that it may not be so easy to develop new weapons against the resistant bed bugs. It seems that some of these genes have actually transferred from symbiotic bacteria carried by the bed bugs.

So if a better pesticide won't be on the horizon to fight the resistant bugs, what can a person faced with bed bugs do? The first line has to be prevention. If you travel, check for bed bugs. Anything you bring home with you can be treated by washing at 45°C (or 115 °F) or by bagging the items and leaving it in the freezer for a week.

Larger items that cannot be washed or frozen can be bagged in plastic and left in a warm place in the sunlight. After a week, place the item in the middle of a sheet or tarp before opening the bag. Wait for the hungry pests to charge out of the bag towards you, then trap them in the sheet and immediately implement the hot wash or freezer treatment to kill the bugs.Take care with anything you buy at garage sales or second hand shops (checking these carefully for fecal spots, little black circles, provides a good clue).

if it is too late for prevention, start with a good mattress cover to minimize nighttime raids. You can check out which natural pesticides are most effective -- but consider working with an exterminator because the proper application and assessment of the effectiveness of the treatment is essential to eliminating these fast-breeding bugs.

And if you do choose pesticides from the traditional spectrum -- organochlorines, organophosphates and pyrethroids -- be sure to hire a professional. Incorrect application and incomplete treatments help the bugs build resistance.

Tags: Bedrooms | Insects | Pesticides


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