Bed Bugs, Cimex lectularius

Cimex lectularius

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A pest of the past? Not anymore. Bed bugs are making a comeback. People associate this biting pest with filthy living conditions, but bed bugs are just as likely to live in clean, uncluttered homes. Get to know the habits and traits of the common bed bug, Cimex lectularius, so you will recognize this nuisance insect.


The adult bed bug is oval and flat, and only about a 1/4-inch long. They lack wings, so you won't see them flying around your bedroom.

Under cover of darkness, they crawl in search of blood, preferably from a human. Bed bugs use a piercing, sucking proboscis to penetrate the skin of their host. Adults are brown, but appear reddish-brown when engorged with blood.

Bed bug young look like smaller versions of their parents. First stage nymphs are colorless; with each molt, the nymph darkens. White eggs measure less than 1 mm in length, and may be laid singly or in clusters of up to 50 eggs.

Although you won't usually see bed bug activity during daylight hours, but you may see other signs of bed bugs. As nymphs molt, they leave behind their shedded skins, which accumulate as the population rises. Bed bug excrement appears as dark spots, and crushed bed bugs will leave bloody marks on bed linens.


Kingdom - Animalia
Phylum - Arthropoda
Class – Insecta
Order – Hemiptera
Family - Cimicidae
Genus - Cimex
Species - lectularius


Bed bugs feed on the blood of warm-blooded animals, including humans. They usually feed at night, often on people asleep in bed and unaware of the insects biting them.

Life Cycle:

A few bed bugs can become a large infestation quickly. One female bed bug may produce up to 500 offspring during its lifetime, and three generations can live per year.

Imagine how many bed bugs you'd have in a year if just one reproductive pair finds its way into your home. As with any pest, knowing its life cycle will help you eliminate it. Bed bugs undergo incomplete metamorphosis.

Egg – The female lays her eggs, usually in clusters of less than 50. She uses a sticky substance to glue her eggs to rough surfaces. Eggs hatch in 1-2 weeks.
Nymph – The nymph must consume a bloodmeal before it can molt. It molts 5 times to reach adulthood. In warmer temperatures, the nymph stage may last just 3 weeks; in cooler temperatures, nymphs may take many months to mature.
AdultAdult bed bugs live about 10 months, though some may live substantially longer.

Special Adaptations and Defenses:

Bed bugs locate their warm-blooded hosts by detecting exhaled carbon dioxide. The hungry pests can also sense warmth and moisture from the bodies of potential victims.

Once the bed bug pierces the skin of a human or other host, it injects salivary fluid to prevent blood from clotting as it drinks. This fluid may cause an itchy, allergic reaction on the skin of the victim.


Bed bugs hide in the folds, crevices, and seams of upholstered furniture and mattresses. They depend on humans, pets, or other animals for their food, so a suitable host must be available for regular bloodmeals.

Once these pests find a meal ticket, they move in for good.


Cimex lectularius lives in temperate climates, especially in the north. Bed bugs infestations are on the rise in North America, Europe, and Central Asia.

Other Common Names

bed louse, mahogany flat, redcoat, wall louse