The Bedbug

Jan 25, 2009 Features / Columnists, Interesting Creatures in Guyana

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Bedbugs are renowned for feeding on the blood of humans and other warm-blooded hosts and are said to be a species of small nocturnal insect of the family Cimicidae, a species which can adapt the best to human environments.

They are found in temperate climates throughout the world. In some areas they feed primarily on human blood, poultry and bats, bats and humans or bats alone.

Adult bedbugs are reddish-brown, flattened, oval and wingless, with microscopic hairs that give them a banded appearance.
However, a common misconception is that they are not visible to the naked eye.

In fact adults can grow to four to five millimetres in length and do not move quickly enough to escape the notice of an attentive observer.

Newly hatched nymphs (baby bedbugs) are translucent, lighter in colour and become browner as they moult and reach maturity.

In size they are often compared to lentils or apple seeds. Bedbugs are generally active just before dawn, with a peak feeding period about an hour before sunrise.
However, they may attempt to feed at other times, given the opportunity, and have been observed feeding at any time of the day.

Attracted by warmth and the presence of carbon dioxide, the bug pierces the skin of its host with two hollow tubes. With one tube it injects its saliva which contains anticoagulants and anaesthetics while with the other it withdraws the blood of its host. After feeding for about five minutes the bug returns to its hiding place.

The bites cannot usually be felt until some minutes or hours later, as a dermatological reaction to the injected agents, and the first indication of a bite usually comes from the desire to scratch the bite site. Because of their dislike for sunlight, bedbugs come out at night.

Although bedbugs can live for a year or as much as 18 months without feeding, they typically seek blood every five to 10 days.

Bedbugs that go dormant for lack of food often live longer than a year, well-fed specimens typically live six to nine months. Low infestations may be difficult to detect, and it is not unusual for the victim not to even realize they have bedbugs early on. Patterns of bites in a row or a cluster are typical as they may be disturbed while feeding. Bites may be found in a variety of places on the body.

There have been some cases where the bedbugs went under the skin. In most observed cases, bites consist of a raised red bump or flat welt, and are often accompanied by intense itching. The red bump or welts are the result of an allergic reaction to the anaesthetic contained in the bedbug’s saliva, which is inserted into the blood of its victim. Bedbug bites may appear indistinguishable from mosquito bites, though they tend to last for longer periods. Bites may not become immediately visible, and can take up to nine days to appear.

Bedbug bites tend to not have a red dot in the centre such as is characteristic of flea bites. A trait shared with flea bites, however, is tendency towards arrangements of sequential bites. Bites are often aligned three in a row, giving rise to the colloquialism “breakfast, lunch and dinner.”

Alternatively, the arrangement of bites may be caused by the bedbug repeatedly searching for a blood vein. People react very differently to bedbugs, and individual responses vary with factors including skin type, environment, and the species of bug.

In some rare cases, allergic reactions to the bites may cause nausea and illness. In a large number of cases, estimated to 50 per cent of all people, there is no visible sign of bites whatsoever, greatly increasing the difficulty of identifying and eradicating infestations.

People commonly respond to bed bug infestations and their bites with anxiety, stress, and insomnia. Individuals may also get skin infections and scars from scratching the bedbug bite locations.

Most patients who are placed on systemic corticosteroids to treat the itching and burning often associated with bed bug bites find that the lesions are poorly responsive to this method of treatment.

Antihistamines have been found to reduce itching in some cases, but they do not affect the appearance and duration of the lesions. Topical corticosteroids, such as hydrocortisone, have been reported to expediently resolve the lesions and decrease the associated itching.

It must also be noted that bedbugs have been erroneously associated with filth in the mistaken notion that this attracts them. Bedbugs are attracted by exhaled carbon dioxide and body heat, not by dirt, and they feed on blood, not waste.

In short, the cleanliness of their environment has an effect on the control of bedbugs but, unlike cockroaches, does not have a direct effect on bedbugs as they feed on their hosts and not on waste. Good housekeeping in association with proper preparation and mechanical removal by vacuuming will certainly assist in control.

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