You might not realize that there are so many different bed bug species. But you need to find out the type of bed bugs that are in your home. That’s because some are immune to certain treatments.
There are two main bed bug types, Cimex lectularius and Cimex hemipterus (common bed bugs and tropical bed bugs). There are other species in the Cimex genus that feed on bats and birds (bat bugs). Cimex isn’t the only bed bug genus; there are a dozen more, some with several species. But none of these feed on humans.
Each of these species looks similar to the others, but they’re genetically closely related. They all feed on blood and leave bite marks. We’ll explain how to tell them apart, and why it’s necessary.
How Many Bed Bug Species Are There?
Regular bed bugs are part of the genus Cimex. There are more than a dozen species in this genus. Cimex are in the order Hemiptera, and are considered true bugs, not just insects.
However, not all of these species feed on people. There are two species in the genus Cimex that are considered ‘bed bugs,’ as a regular person understands.
These are Cimex lectularius and Cimex hemipterus. These two species are, respectively, known as regular bed bugs and tropical bed bugs.
The other species in the genus Cimex don’t feed on people. You will never see them in your home, and they are difficult to find in the wild.
Species include swallow bugs, bat bugs and more. If you include each of these species in the list of bed bugs, then there are a dozen or more.
Aside from the genus Cimex, several genera are considered bed bugs too. These are as follows:
- Ornithocoris
- Cimex
- Cimexopsis
- Haematosiphon
- Hesperocimex
- Oeciacus
- Primicimex
- Synxenoderus
The species in each of these genera look like bed bugs, and feed on blood. However, these species seldom interact with humans. Some of them are hardly known to science, and there’s little information available on them.
Only the two species that are known to live in human homes are classed as true bed bugs.
Different Bed Bug Species
The two main species are quite similar to one another. Even the other species (bat bugs and others) look similar to bed bugs. Below, we explore the differences between each of them plus information on where you find them.
Common Bed Bugs (Cimex Lectularius)
Cimex lectularius is the most common bed bug species, both in the U.S. and worldwide. They have been steadily increasing in number since the 1990s. Today, they can be found in every state of the U.S., and in European countries too.
If you’ve ever seen a bed bug, you’ll know what they look like. These bed bugs are:
- The size of an apple seed
- Rounded at one end, and pointed at the other end (again like an apple seed)
- A dark brown color
- Broad but flat like a bank card, so that they can fit into cracks
- Slightly hairy, which you can see if you get up close
They have six medium-sized legs, four that point backward and two that are straight out, or point ahead slightly. They drink blood through a straw like a mosquito.
Common bed bugs seek out dark and enclosed spaces for safety. Anywhere like a crack in the wall or floorboards, or under furniture or your mattress will do. Here they lay their eggs, and live in large aggregations.
Tropical Bed Bugs (Cimex Hemipterus)
Tropical bed bugs are similar to regular bed bugs. The main difference is that they prefer tropical and subtropical habitats where it’s warmer.
Specifically, they are usually found within 30 degrees latitudinally north and south of the equator. This means that this is the most common species in Asia, Africa, and South America. However, they can be found anywhere that’s warm enough.
Cimex hemipterus look the same as regular bed bugs. They are the same size, flat, and are brown and rounded too. Infestations look the same, as do the bed bug feces and shells they leave behind. The physical differences are only slight and unnoticeable.
Tropical bed bugs behave in the same way as regular bed bugs, too. They seek out small enclosed spaces and typically live underneath your mattress.
You need either experience as a pest controller or a microscope to tell the difference. If you want someone to identify which species you have, you’ll need a pest controller or researcher.
Tropical bed bugs are the second most common species in the U.S. They were made extinct in the U.S. in the 1940s through extensive use of DDT. Even regular bed bugs were almost made extinct at this point.
However, they made a comeback in 2016 when they were reintroduced to Florida. They were first identified by researchers at the University of Florida at this time. They have since spread across the southern U.S. where the temperatures are hot enough to sustain them.
Bat Bugs and Bed Bugs That Feed on Birds
Bat bug species are, in a way, the ‘original’ bed bugs. Cimes lectularius and hemipterus evolved from bugs that fed on bats. They look the same, fed on blood, and lived in caves.
When people started living in caves to escape the elements, some species started feeding on us instead. These bugs continued feeding on us when we lived in houses instead. They become today’s bed bugs.
However, some species stayed in the caves and still feed on bats. Other species feed on birds instead, and live inside their nests.
Cimex Adjunctus or Leptocimex Boueti
Cimex adjunctus is a similar species to common bed bugs. In terms of appearance, you can’t tell the difference between these and bed bugs. They are brown, flat, and the same shape.
This species feeds on insectivorous bat species, e.g., the big brown bat. They live in the cracks of the dark caves the bats live in. When the bats are asleep, they come out and feed on them. On occasion, they have been found on bat’s wings during flight. But this is rare.
Unfortunately for the bed bugs, the bats are insectivorous. This means that they eat insects. If the bat finds one of the bed bugs, it will eat it. This happens frequently.
Swallow Bugs (Oeciacus Vicarius and Hirundinis)
These bugs are part of the family Cimicidae, the family of bed bugs. However, they are part of a different genus, Oeciacus. They are therefore considered bed bugs in a way, although they don’t feed on people.
They look similar to common bed bugs in almost every way. The only difference is that they have longer hairs on the foremost part of their shell. Aside from that, they’re the same color, size, and shape.
Rather than feeding on people, these bugs feed on birds. Specifically, they feed on swallows. Swallows have nests, unlike other birds. If anything, they look more like wasp nests. They’re enclosed and dark spaces for the baby birds to live safely.
They mostly feed on cliff and barn swallows. Unfortunately, dark enclosed space is perfect for bed bugs too. American swallow bugs (Oeciacus vicarius) sit in the nest with the swallows and feed on them. They feed on blood just like our bed bugs do. European swallow bugs (Oeciacus hirundinis) are much the same.
Like our infestations, occasionally swallow bugs can breed too much. If a nest is heavily infested, then the nestlings might have to abandon it before they’re ready. The adults might be forced to abandon the nest too.
Swallow bugs can live in a nest for a year without food, like our bed bugs. They have to, because the nests are empty when it isn’t breeding season.
Hesperocimex Coloradensis and Hesperocimex Sonorensis
These two species are a part of their own genus, Hesperocimex. Another species called Hesperocimex cochimiensis has also been described. Each of these species is from the Midwest or west coast U.S.
They feed on a variety of animals in the wild, usually bats or birds. According to Wilson Bulletin, hundreds have been found feeding on pygmy owls. They go where their hosts are, which can even include inside cacti, where bats occasionally roost.
Haematosiphon Inodorus
Haematosiphon indorus is also known as Mexican chicken bugs. They are mostly the same as common bed bugs, but they developed to feed on chickens. If you raise poultry, you may have come across them.
Today, common bed bugs and other species are as likely to feed on chickens as Mexican chicken bugs. They are controlled in the same manner as other bed bug species.
Cimexopsis Nyctalis
These bugs are also known as chimney swift bugs. They look a lot like bed bugs, with slightly longer legs. They are the same size and shape, and feed on blood as well.
However, there are several differences between chimney swift bugs and bed bugs:
- Chimney swift bugs are active during daytime hours, not just night.
- These bugs can climb sheer and slippery surfaces.
- Chimney swift bugs prefer living in walls or other voids to living in mattresses.
They usually feed on chimney swifts, a kind of bird. But they can also feed on people.
Ornithocoris Pallidus and Toledoi
These are yet more bed bugs that feed on birds. They feed on martins (a bird species), and live on the Gulf Coast, down to South America. Like Mexican chicken bugs, they may also feed on backyard poultry.
Again, the differences between these species are minor. O. toledoi are a dark brown color while O. pallidus is lighter. Other than this, not much is known about species in this genus.
Primicimex Cavernis and Bucimex Chilensis
The two species are closely related. They live in Central and South America, and are much bigger than bed bugs.
In Central America, P. cavernis lives in a specific habitat. In this area, bats roost in tall cacti that have had holes made in them by woodpeckers. P. cavernis lives there too, feeding on them. They can also live in caves. Wherever the bats are, P. cavernis are there too.
These bugs are much larger than an average bed bug. Common bed bugs are the size of apple seeds. These bugs are ¾ of an inch long. They have long, thick legs more like a spider than a bug.
Synxenoderus Comosus
Almost nothing is known about this species, apart from it living in the U.S.
Other Bed Bug Species in the Genus Cimex
These aren’t the only other bed bug species. There are many more that live either in the U.S., or across the world. The following list is all the other bugs in the Cimex genus.
- Cimex antennatus, a kind of bat bug from Pacific North America
- Cimex brevis, a rare bat bug species from North America
- Cimex columbarius, which infests pigeon nests
- Cimex emarginatus, a bat bug from the Balkan Peninsula (eastern/southern Europe)
- Cimex incrassatus, another rare North American bat bug species
- Cimex japonicus, a bat bug found in Japan
- Cimex latipennis, bat bug from Pacific North America
- Cimex pilosellus, bat bug found in the northern United States and Canada
- Cimex pipistrelli, a European species of bat bug
Each of these species looks almost exactly like regular bed bugs. Again, if you compare them to common bed bugs, it’s difficult to tell them apart. They are closely related species.
However, it’s highly unlikely that you will encounter one. They live in caves and nests, which are in nature, but don’t allow them to contact you easily. Some were more common historically and are less common today.
Bed Bug Species Identification
The two main species listed above, the common and tropical bed bugs, are almost identical. You can’t tell them apart with the naked eye. However, they do have some physical differences you can spot with a microscope. According to BioOne, these differences include:
- Pronotum width to length ratio. The pronotum is the upper part of their shell. In tropical bed bugs, the pronotum is a little wider and a little longer.
- In tropical bed bugs, the pronotum is more upturned than in regular bed bugs.
- The common bed bug’s pronotum has more of a u-shape.
These physical differences are technical and challenging to understand. Only expert pest control professionals and researchers can tell the difference. So, don’t worry if you can’t.
There are also minor differences in behavior between the two species. Tropical bed bugs lay fewer eggs than common bed bugs. Adults may therefore not need to feed as often.
This is offset because tropical bed bugs develop more quickly than common bed bugs. This may be because of genetic differences, or because bed bugs develop quicker in warm weather — the exact reason why is unclear.
How to Get Bed Bugs Identified
There are two ways to identify which bed bug species are infesting your house. The first is to talk to a professional exterminator. They may be experienced enough to tell the difference.
If they keep up with pest news, they may be aware of tropical bed bugs in the area. Pest controllers share information and stay abreast of news in their profession. Admittedly, there is little point, as they use the same treatments for each species.
If the pest controller you speak with doesn’t know, you’ll need to talk to a researcher. Since bed bugs have come back, researchers have begun testing them, and learning how to kill them. The University of Florida is an example.
There is no guarantee that there will be a bed bug researcher at a college near you. But even if there isn’t, that isn’t a problem. Exterminators use the same treatment methods for both species, so it doesn’t make a difference.
Why is Bed Bug Species Identification Necessary?
So, they look the same, they feed in the same way, and they leave the same bite marks. So, what is the point in identifying which species you have?
This is a question that even pest controllers don’t answer. Most pest controllers will check, see something that looks like a bed bug, and start spraying. But there may be reasons why it’s worth seeing which species you have.
Tropical bed bugs haven’t been studied extensively. That’s because the U.S. has only had common bed bugs in recent history. So, all the university research that’s been done on ‘bed bugs’ was only done on common bed bugs.
This means that scientists aren’t sure how effective specific treatments are against tropical bed bugs. It’s possible that particular insecticides are more, or less, effective against one species than another. Learning which species you have could help in that regard.
Not only that, but tropical bed bugs can climb out of plastic containers that common ones can’t. This is a major issue because it means bed bug traps won’t work against them. You should, therefore, look to get a specimen identified if it’s possible to do so.
