of the bite(s) is very useful to a pest controller in diagnosing the
biting species. Flea bites are most commonly on the lower leg or ankle, whereas bed bug bites are often on the face, neck
arms or hands, and occasionally around the waist.
Where do they live? Within the urban ecosystem, there are three primary components, the human and non-human and
the physical structures. The habitat that is made up of human settlements is known as “Anthropobiocoenosis”. Probably
the biggest word ever used in Pest Control News, this lengthy term means the part of the environment that has been
completely changed by man. It can even be sub-divided into “peridomestic” habitats, which are those outside dwellings,
and “domestic” habitats, which are located inside dwellings. The bed bug has invaded most areas of the latter category,
but principally those areas where we sleep. This is because time is needed to take a blood meal, and unless you are a
couch potato, humans do not sit still long enough for this to occur in the sitting room!
Control of bed bugs has always been relatively straightforward, although often a great deal of searching and a thorough
treatment or series of treatments was needed. However, in recent months, reports have been appearing in the national
press of “super infestations” of “resistant mutant bed bugs”. This situation needs explaining.
It is known that the incidence of bed bugs is increasing, especially in London and in some of the university towns and
cities such as Cambridge. It is also known by a number of pest controllers that several populations are becoming very
difficult to treat successfully. Expressions like “pesticide-resistant” are thus bandied about. Such a term is not warranted.
True resistance is a biological term, meaning a population which, over time, has become “immune” to the effects of a
pesticide. This can only be conferred by surviving adults to their offspring and so takes time and several generations. The
instances reported in the press are more likely to be ones of “tolerance”, whereby the bed bugs are able to tolerate a
pesticide and survive. (The offspring of these survivors would therefore be “resistant”).
Like all treatments where a given product appears not to work, the selection of a pesticide from another group of active
ingredients if often the answer. Currently, the infestations that are causing some difficulty seem to be able to tolerate the
use of pyrethroids, and some are also carbamate-tolerant.
Nigel Binns, Biologist for Killgerm Chemicals Ltd., commented: “We are receiving a number of phone calls where
technicians are experiencing difficulty in controlling bed bug infestations. If they have used pyrethroids and/or
carbamates, a return to the use of organophosphorous pesticides usually does the trick. The down-side to this is that they
are often a little ‘smelly’, and so the customer should be advised. Organophosphorous pesticides that are approved for
use as public health products are perfectly safe in such situations, providing the technician follows the label
recommendations.”
Finally, the bed bug does have predators. T. Pergande, a Union soldier in the American Civil War, reported that Pharaoh’s
ants (Monomorium pharaonis) attacked and dismembered bedbugs in an infested quarters in Mississippi – perhaps this
is a novel form of biological control that we could choose to employ. Two infestations for the price of one!
Cockroach and dust mite
Many allergies are well-recognised and understood, but insect and mite allergies are still being examined. A study in 1997,
supported by the US National Institute of Allergy and Infectious Diseases (NIAID) conclusively demonstrated that the
combination of cockroach allergy and exposure to the insects is an important cause of asthma-related illness and
hospitalizations among children in U.S. inner-city areas.
“Some of the most vulnerable of our citizens, children in the poorest neighbourhoods of our large cities, suffer
disproportionately from asthma,” says Anthony S. Fauci, M.D., NIAID director, in the report. “Allergy and exposure to
cockroach allergen clearly play an important role in the alarming rates of asthma-related sickness among these children.”
“Reducing exposure to cockroach allergen, as part of a multi-faceted approach to asthma management, may be a cost-
effective way of reducing the burden of this serious disease,” says Daniel Rotrosen, M.D., acting director of NIAID’s
Division of Allergy, Immunology and Transplantation. “Simple and relatively low-cost interventions that have been explored
in the NCICAS, such as patient education, roach traps and child-safe insecticides, are potentially important.”
The first five-year phase studied
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