Pest Resources

The Bed Bug Life Cycle


They’ll never be a welcome tenant in our homes, especially when they’re not paying rent. But, bed bugs are still one of the most common pests faced within homes across the USA.

So, it’s important to understand what bed bugs are, where they come from, how to identify them, and how to get rid of them. In order to do that, we must first understand the life cycle of the bed bug. This is because at each stage of the bed bug life-cycle, they are identified differently.

There are 7 stages within a bed bugs life-cycle that can be split into three categories: the egg stage, the nymph stage, and the adult stage.

While the eggs produce reactions of ‘Ew!’, the adult bed bugs bring on more ‘Ouch!’ responses from us humans.

How Long is the Bed Bug Life-Cycle?

Knowing the length of the bed bug life-cycle can be important in understanding how to exterminate them and how long the eradication process may take.

For a bed bug egg to grow through all nymph life stages and into a fully grown adult, it can take up to 37 days.

There are, of course, some conditions of the environment that can either elongate or reduce this time period. For example, optimal conditions for the bed-bug to mature include temperatures of 80 ° F, a dark home, as well as regular contact with a host. This way the eggs are kept warm and secure and when they hatch, they have constant access to their blood food source.

However, if temperatures exceed 90 ° F or fall below 70 ° F, the bed bugs can either die or take a third as long to reproduce.

Not-so-fun fact: In optimal conditions, the bed bug population has the ability to double within the space of 16 days!

What are The Types of Bed Bugs?


Although a horrifying question to see as it sparks questions like ‘wait, there’s more than one?!’, unfortunately, the answer is yes.

There are around 90 species of bed bugs that are known across the globe. However, some good news would be that only three of these breeds will actually feed on humans.

• Cimex Hemipterus
• Leptocimex Boueti
Cimex Lectularius

There is one species in particular that likes to use us as a blood meal, and this is the Cimex Lectularius. This is because these bed bugs can be found in any temperate climate, from the USA and Canada to Europe.

On the other hand, Cimex Hemipterus has only caused an issue for those living in the warmer US states such as Florida and California.

Leptocimex Boueti is also commonly referred to as the Bat Bug because – even though it won’t be picky about having a human blood meal – they are most commonly found feeding on bats in Africa.

Telling bed bugs apart is no easy feat, as they are so small, their differences are quite minimal and only tend to appear to the trained terminator. However, if you’re up for a creepy-crawly challenge, the Cimex Lectularius has a wider prothorax (the segment of an insect that has the first pair of legs) than their cousins in tropical climates.

The Egg Stage

For now, we will focus on the Cimex Lectularius bed bug, as it is the most common bed bug in the USA.

Most insects reproduce by laying eggs, and the bed bug is no exception. The egg of a bed bug is very small and is sometimes hard to identify. They will generally begin as 1mm to 1.5mm in length and are a milky-white color.

The bed bug eggs hatch into nymphs after around 6 to 10 days, and will depend on those environmental conditions we mentioned earlier. If in doubt, sleep in your freezer!

The Nymph Stage


As mentioned earlier, there are in fact 7 stages to a bed bug’s life-cycle. Five of these stages happen within the ‘nymph’ category. Then, it will become a fully grown adult.

When an egg successfully hatches, it will become a 1st stage nymph – or, baby bed bug – and start feeding on its closest blood source. This could be a bird, dog, cat, mouse, and so on. However, it would always prefer and thrive on human blood meals.

A nymph needs a blood meal at least once a week. When it feeds, it will then have the ability to molt into the next stage. Hence, 5 stages of the nymph before becoming a full-sized adult.

With each molt, the nymph grows and it can be easier to tell how close to sexual maturity the bed bug has become:

• As an egg the bed bug is 1-1.5mm
• As a stage 1 nymph, the bed bug will be approximately 1.5mm
• At stage 2, the nymph will be 2mm long
• At stage 3, they’ll be 2.5mm
• At stage 4 they grow to 3mm
• At stage 5 they become 4.5mm
• At maturity, an adult bed bug will engage in its biggest molt and will grow to 5.5mm in length

If a nymph is unable to feed in a week, the duration from egg to adult will simply be prolonged. However, a blood meal lasting around 5 to 10 minutes does need to take place before a molt can occur. This is why they will generally feed at night while the host is asleep so they can enjoy an undisturbed meal.

The Adult Stage

When the nymph has begun its final molt, they will turn into an adult bed bug. During this process they will change from their youthful yellowish-white color to a more reddish-brown color.

A bed bug’s exoskeleton is quite transparent. So, when the bed bug feeds, you can see it’s blood meal inside it’s body. Then, at full maturity, the bed bug’s exoskeleton has had a chance to harden using our blood, hence the reddish-brown color.

A fully grown adult will be approximately the size of an apple seed, so don’t be eating any apples in bed; you may scare yourself.

It is hard to get rid of an adult bed bug, as they can live for a year without feeding depending on the temperatures.

How Do Bed Bugs Reproduce?


A bed bug can only reproduce when they have reached maturity after 5 weeks of molting.

And, when the bed bugs have reached sexual maturity, they will reproduce through a process called traumatic insemination. During this time, a male bed bug will stab the female bed bug in the abdomen with his reproductive organ.

When the eggs have been fertilized, they can stay inside the mother’s abdomen for a further 5 weeks while she continues to take blood meals from the host.

How Often Do Bed Bugs Lay Eggs?

Female bed bugs will lay an average of around 250 eggs in their lifetime. This is between one and five eggs a day, keeping the females quite busy.

Sometimes females will lay their eggs singularly, and other times they may be in clusters, which will allow you to see them a little easier. Some have said that in this case, it’s akin to seeing a few grains of salt.

In terms of the location, the female bed bug will often find a tight crevice to lay her eggs. These crevices will generally be the seams around your mattress or in the seams of furniture. So, when you’re looking around for your bed bugs, be sure to check every single seam, edge, and crevice!

Bed Bug Life-Cycle Summary

And, there you have it, the complete bed bug life-cycle. If you suspect an infestation, please contact your local pest control service. They will carry out a thorough investigation and provide you with details on how to exterminate.

For more information, check out some of our other guides:

Ronald has 25 years of pest control experience under his belt. He scrutinizes each pest control method, product and process. Each pest resource we list on our website goes through an in-depth fact checking process.

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