How they live

Bedbug eggs are cemented to the surface of the harbourage, often in large numbers. Temperature and the availability of food have a profound effect on egg production and under ideal conditions can be almost continuous, at a rate of about three per day.

The eggs hatch to produce a nymph just over 1 mm long and like all nymphal stages appear similar to the adults apart from size and colour. The nymph requires one full blood meal before moulting to the next stage.

Development from egg to adult and the duration of adult life varies according to temperature and the availability of food. At 18 - 20°C nymphs feed about every ten days and the adults weekly.

If necessary both can survive long periods without food. In unheated rooms where the temperature drops below 13°C in the winter, egg laying and feeding stops and the population declines as eggs and young nymphs die.

Control

A thorough inspection should be made to determine the extent and source of the infestation, Bedbugs may, for instance, have been introduced in second-hand furniture, where bugs may remain undetected for considerable periods until a suitable host appears.

All harbourages should be treated with a residual insecticide. A very thorough treatment is needed as harbourages are diverse and difficult to detect.

Biology

Female bedbugs lay eggs throughout their life, an unusual feature in insects.

They generally produce around 2 to 3 per day and since they can live for many weeks, indeed months, each female could produce around 400 - 500 eggs during her lifetime.

The eggs are deposited all around the environment in which the bedbug is living and are small and white or whitish/yellow about 1 mm long. The nymph which emerges from the eggs after about ten days at 22°C is a small version
of the adult, feeding also on the blood of vertebrates. The length of time spent in the five nymphal stages is greatly dependant on the food resources available, temperature and relative humidity.

Bedbugs have well defined resting sites in which many individuals from all the different life stages are found. This harbourage is an essential part of the life cycle of the insect since it is in this area that the young bedbugs pick up the internal gut microorganisms which are essential to there survival.

How they affect you

A property infested with bedbugs may be classified as being "in a verminous condition" under the Public Health Act 1936. Owners of these premises may be obliged to have them disinfested.

Although bedbugs are not regarded as disease carriers their blood feeding can cause severe irritation in some people, resulting in loss of sleep, lack of energy and listlessness, particularly in children. The bite of a bedbug often gives rise to a hard, whitish swelling which is different from a flea bite which leaves a dark red spot surrounded by a reddened area. People react differently to bites, some gaining immunity.

The excrement of a bedbug gives a characteristic speckled appearance to their harbourages. They also have stink glands which confer a distinctive and unpleasant almond like smell in infected rooms. The thought of being preyed on by bedbugs is normally sufficient to make most people take immediate action for some form of control.