Nothing makes the skin crawl more than the idea that tiny bloodsucking bugs could be living in our bedrooms. Around the size of a lentil, the common bed bug*, Cimex lectularius, can drink up to seven times its own weight in blood in one feeding, leave nasty, itchy bumps on their human hosts, and hide unseen for months on end.
Since the late 1990s, the bed bug has become an increasingly common urban nuisance in homes and hotels worldwide. A 2010 survey from the University of Kentucky and the National Pest Management Association found that 95% of US pest control companies had treated a bed bug infestation in the previous year, up from 25% a decade before, and 11% before that. Only last month, New York’s Department of Health and Mental Hygiene, a resource for other people with bed bug infestations, had to fumigate one of its floors.
According to the survey, the majority of pest control operators from Europe, Africa, Australia and North America said bed bugs were the most difficult insect pest to control, more so than ants, termites and even the formidable cockroach. Another study showed that in London alone, bed bug treatments grew by a quarter each year between 2000 and 2006.
The worst aspect about this is that we thought we had tackled the bed bug problem before. Clive Boase, a pest management consultant in Suffolk and author of the London survey, says that UK bedbug numbers began decreasing in the 1930s, thanks to changes in social housing and public health policies, which led to the demolition of old publicly-funded housing and teams of inspectors checking homes for vermin, respectively. New pesticides introduced in the 1940s, including DDT, also helped to bring numbers down, and by the 1950s infestations were rare. The US saw a similar drop in infestations from the late 1940s onwards, thanks to the advent and widespread use of DDT and other chlorinated hydrocarbon pesticides.
So, where is the chemical cure this time around? Or, is there any relief to be found in the myriad bed bug products and services on the market, from growth regulators to heat treatments?
The pesticides currently available, says Dini Miller, an entomologist and bed bug expert from Virginia Tech, are “not practical to use in a widespread way because of the cost.” New, cheaper pesticides are too expensive and time consuming to develop, she adds. Because bed bugs live primarily in the bedroom, chemical companies must provide extensive toxicity data to prove it is safe for indoor use, as it might come into contact with people or pets.
But, proving that a pesticide works and is safe could cost a company up to $256 million over eight to ten years for each active ingredient, according to a 2010 industry study conducted for Crop Life America and the European Crop Protection Association. The investment may not be worth it. The US accounts for over a fifth of the world’s pesticide use, the vast majority of which is used in agriculture, followed by herbicides and then insecticides. Compared to the vast expanse of farmland and orchards, the real estate of all of the apartments and houses in the world combined is small and brings in less money, says Miller. This is especially a problem considering patent protection on a novel ingredient runs out after around 20 years, after which the tech is open to generic competitors.
Even if making a new bed bug insecticide were lucrative, there are other challenges. There is the problem of figuring out how a chemical has to function in order to best kill bed bugs cheaply, efficiently and safely. This requires intimate knowledge of the bed bug’s basic biology. But, because bed bugs were at such low levels for decades, interest in studying them waned. Starting in the early 2000s, once it was clear the resurgence was real and that bed bugs weren’t going anywhere, scientists had to relearn bed bug basics from scratch, starting with fundamental aspects as how to raise them in a lab.