Description of Bed Bugs
(Cimex lectularius)

Habitat

Nocturnal parasite, all stages feeding on mammalian blood, principally human but also dog, cat or rodents. Hide by day in crevices in beds, furniture, wallpaper, skirting boards and emerge when hungry, usually every few days to feed.

Biology

Egg – nymph – adult.
Eggs – up to 200, possibly more, laid at a rate of 4–5 a day glued in crevices and harbourages.

Eggs white with cap.

Only hatch above 13 °C.
Nymphs – 5 moults, taking from a few weeks to several months depending on food supply and conditions.

Adults – wingless, flattened unless recently fed, about 6mm long.
 

Importance

Bites may cause severe allergic reaction but not a known disease carrier. Infestations are often, but not exclusively, associated with poorer housing where the insects may be transferred on second hand furniture and bedding. Also lodging houses, hostels, hotels. May be carried on luggage.

Control

Thorough residual treatment of all harbourages in bedding, furniture and structure of infested buildings, sometimes including ducts, roof voids and electrical cable paths.

Distribution and Habitat

The bed bug is found worldwide, and throughout Britain. It still occurs surprisingly frequently, but is generally now associated with poorer properties in large towns. It is now becoming more common in hotels and hostel accommodation. It is associated with human habitation, hiding in furniture and structural cracks and crevices, emerging at night when hungry to search for blood meals.

Biology

Mating takes place off the host, the female attaching up to 200 eggs to the structure in small numbers of four or five per day. The local environmental temperature must remain above 10  – 13 °C for the eggs to hatch. The resultant nymphs resemble the adults in miniature and develop through a series of moults (usually five) to reach full development. This takes from as little as a few weeks to several months (averaging about four months) depending on temperature and food supplies.

All nymphal stages feed on rnammalian blood (including other animals in domestic situations: dogs, cats and rodents), emerging at night, when hungry, to search for prey. Feeding usually takes about 10 minutes. Bed bugs produce a characteristic smell from their faeces and scent glands. Although they can walk upside down on ceilings their falling onto a sleeping host is accidental. They can ingest up to seven times their body weight in blood at any one meal, but may go for prolonged periods without feeding. The adults are highly resistant to starvation (up to one year) and low temperatures, but under suitable conditions several generations per year are possible.

Importance
 

The widespread introduction of central heating has extended the northern limit of the bed bug considerably, although nationally it occurs less commonly than in the past.

Bed  bugs are not known to be frequent carriers of disease and their importance is related mostly to the unpleasant irritation following their bites. Heavy infestations are characterised by a distinctive odour. There is also some suggestion that bed bugs may be partly responsible for the lowering of social standards in an area of infested housing, where some householders are tempted to move away from the area to avoid the trouble and the stigma.

Control
 

Thoroughness is required and it is important to find and treat harbourages. Adult bugs and nymphs may be found by searching likely hiding places and by using a flushing aerosol. Smears or spots of excrement may be seen close to harbourages as fully fed bugs remove excess water before returning to their narrow crevices. Eggs or egg cases may be visible in harbourages. Bugs can survive many months in the absence of a host.

The structure of infested rooms should be sprayed or dusted according to situation with a broad spectrum residual insecticide, paying particular attention to bed frames, skirting boards, wall switches and any other cracks and crevices likely to shelter adult or nymphal bugs. If possible, bedding materials including the mattress should be disposed of, or heat sterilised. Insecticide resistance is suspected in some populations and should be considered if thorough treatments fail to control. There will generally be a need for two to three repeat treatments in order to achieve successful control.

 

Wherever possible, likely harbourages should be sealed after treatment with a residual crack and crevice insecticide. If problems persist a further survey, possibly at night and using a pyrethrins aerosol, may indicate harbourages that have been missed.