Bedbug Trivia

1. Growing up is hard to do

All bedbugs go through 5 immature stages between an egg and adulthood. Immature bedbugs are called nymphs. To go from one stage to another, the immature bedbug must take a blood meal. Then, in 7 to 10 days, depending on temperature and humidity, the nymph molts, shedding its exoskeleton and emerging in a larger, more mature stage of development. This process is repeated until the bedbug is an adult.

2. Hungry? Dine slowly, and late at night.

Adult bedbugs often take blood meals every 7 to 10 days or less, depending on temperature and humidity. Bedbugs feed for 10 minutes or more, so it is safer to attack when you're sleeping most soundly.

3. No reaction, but still not clueless

50% of people do not react to bedbug bites, so there is no visible welt or bite mark. Bedbugs defecate while feeding or immediately afterward, so reddish brown stains on pajamas or bed linens are a clue.

4. Keep looking

Because bedbugs feed sporadically, continuous monitoring for a minimum of one week and preferably for two weeks is necessary to detect new or light infestations. New infestations may result from "hitch hikers" carried in travelers' luggage, or foraging bedbugs from an adjacent unoccupied apartment seeking a replacement blood-host. Light infestations are those in which a few, newly arrived bedbugs have begun to feed, but have not yet reproduced in large numbers.

5. Home sweet home, nice neighborhood, growing community

In between blood meals bedbugs congregate in refuges which they mark with an aggregation pheromone. Bedbugs return to the refuge between blood meals. Refuges provide shelter and mating opportunities, and a place to lay eggs. Females lay about 3 eggs per day, and up to 200 eggs in their lifetime, so populations expand rapidly when food and shelter are available.

Narrow crevices in solid structures, such as the joints in the bed's headboard or between the wall and the base board, for example, are the bedbugs' refuge of choice. Rick Cooper, an expert in the field, notes that by the time bedbugs are found in the soft mattress ticking, they have already infested the headboard, night stand, and adjacent wall.

6. Kinky sex... or evolution at work?

Males in the insect world often make adaptations to insure that their sperm wins the competition to fertilize the female, and not that of other males mating with the female afterward. A mating-plug, for example, which prevents other sperm from reaching the females' eggs, is a common strategy. Although male and female bedbugs are physiologically equipped to mate "normally", they practice traumatic insemination.

Traumatic insemination, also known as hypodermic insemination, is the mating practice in which the male pierces the female's abdomen with his penis and injects his sperm through the wound into her abdominal cavity. The sperm diffuse through the female reaching the ovaries and resulting in fertilization.

The evolutionary origins of traumatic insemination are disputed. Suggested reasons for its development include as a new mechanism in the sperm competition, as a counter-adaptation to the mating plug, or as a way to overcome female resistance to being mated.

Bedbugs, which reproduce solely by traumatic insemination, have evolved a pair of sperm-receptacles, known as the spermalege. The spermalege reduce the damage to the female bedbug during traumatic insemination.

7. I'm out of here!

Traumatic insemination is detrimental to the female's health. It creates an open wound which impairs the female until it heals and is susceptible to infection. The injection of sperm and ejaculatory fluids can also trigger an immune reaction in the female.

Traumatic insemination may be the reason female bedbugs leave an established refuge to find a solitary one some distance away.

8. Starvation diet? Then move...

When a dwelling is no longer occupied, bedbugs can go without blood meals for extended periods of time, again depending on temperature and humidity. Bedbugs begin to forage for blood meals if they have not fed in two weeks. In a multi family dwelling, they may move from one apartment to another, for example.

9. ...or just chill

Bedbugs have been known to survive for two to six months without a blood meal. Survival is extended in high humidity, and shortened in low humidity. Unfed bedbugs are not active in the absence of a blood-host, but reactivate in the presence of a blood-host, making it necessary to monitor for several days in an unoccupied - but previously infested - dwelling.

Why don't people know they're being bitten?

Imagine that two bedbugs come home with you in your luggage. In the first week to ten days, you'll be bitten twice. You may not have a reaction to the bites (50% of people don't), but lets assume you do. You have two bites which look like a small pimple. You ignore them.

Two weeks pass. The female has laid over 40 eggs. Now the first nymphs, as small as the head of a pin, hatch and bite. You are being bitten about once every other day. You still don't notice.

Two more weeks pass. Now you're bitten every day, perhaps two or three times. It looks like a rash or chaffing. You probably ignore it.

Two more weeks pass. The population of bedbugs is about 100 and you're bitten multiple times per night. Bedbugs have established multiple refuge sites and may have moved elsewhere in the bedroom or to other rooms.

At some point in the coming weeks you'll recognize the infestation, probably because you see an insect in a sleeping area or in a sitting area.