If you have cockroaches in your home, knowing their sex might seem trivial. The fact that they’re in your house is surely bad enough. However, understanding the difference between males and females can help you determine if you have a small or large infestation. Females may reproduce on their own and expand your infestation. Likewise, tracking a female down can enable you to locate batches of eggs.
Male and female cockroaches can be identified by their body types and appendages. Females are usually larger than males and have longer antennae. Their wings may not be functional and will lie dormant on their back. Males have long and broad wings, matched to a slender body. Females have wide bodies and may even travel in groups.
Females have a divide at their sternum, while males don’t. In contrast, males will have styli between their cerci, and females don’t. Using a few of these identifiers will help you single out the female roaches.
How to Tell Male and Female Cockroaches Apart
No matter the sex, according to Pest Control, roaches carry a variety of bacteria that can result in food poisoning or serious diseases. Here are the main differences between male and female roaches:
Size is one of the most easily recognized differences between males and females. Female cockroaches are usually larger. This is because they need more space for their reproductive parts. They also need room to carry the eggs before laying them in an ootheca.
If you see two cockroaches together and one is larger than the other, then there are two possibilities:
- One is younger than the other and is still molting into its full size
- The larger one is the female, and the smaller one is the male
To be sure, you can look to the other identifying features:
The body shape of male and female cockroaches also differs. The abdomen of the male cockroach is slender, while the female has more of a boat shape. The last segment of the male tends to be pointed. The female cockroach’s last segment is blunt.
This remains true no matter their age. You can even tell some nymphs apart in their development stage by this indicator.
Depending on the species, the male cockroach might have the ability to fly, while the female does not. If you see one fluttering around, then there’s a high chance that it’s male.
Outside of that, male cockroaches have a longer wingspan than females. Their wings extend 4-8 mm. beyond the end of the abdomen. The wings on the male cockroach will also be wider, covering more of his back.
For some species, the female will have very short and blunted wings. They may not spread out; they instead work as leathery shields for her back. This protects her from harm, instead of letting her take to the air.
Most cockroaches have a pair of slender, jointed cerci at the tip of their abdomen. The cerci are simply a pair of appendages, resting near the end of the body. They are segmented, and that’s where male and female cockroaches differ.
Male cockroaches have 18-19 segments in their cerci. Meanwhile, females have only 13-14 segments.
The styli are between the cerci at the end of the abdomen. Even among cockroaches, they’re used to determine who is male and who is female. Roaches use a combination of pheromones and the visual sight of these styli to see which mates are ready and able to breed.
Male cockroaches have styli and females do not. It may be a small difference, but it’s a way to tell for sure what sex they are.
For most people, it will be hard to spot these little appendages. It’s better to use the other features at a glance, and rely on these only if you’re inspecting a dead roach.
Across their entire bodies, roaches are broken into segments, just like at the cerci. This makes their rigid exoskeleton more flexible and allows them to navigate more freely. In the seventh segment of their body, you can find a difference between males and females.
This spot is referred to as the sternum. In female cockroaches, the sternum is divided. In male cockroaches, it’s solid.
Cockroach antennae are another place where males and females vary. Male cockroaches have shorter antennae than females. This not only accounts for their smaller body size. The appendages even seem a bit stocky.
The females will have notably long, almost flowing antennae. This should make the difference easy to spot when you see a roach crawling around your home.
According to the Journal of Animal Behavior, cockroaches use their antennae to adapt and feel their surroundings. It’s one of the most important parts of their anatomy. Science is still exploring whether or not the longer set of antennae make female cockroaches more perceptive or adaptable.
Female cockroaches tend to organize in groups and will push the males out. Because they’re larger in size, it’s easily done. Males do not form groups like this, and tend to forage alone.
If you see a group of roaches, chances are, they’re all female. Any cockroaches that are found wandering alone or separated from the group are males.
Females partly do this to deflect male advances, or at least keep them away at certain times. When around members of their own sex, there is no need.
Of course, roaches do not form hunting parties. The females will not work together, but merely ignore and tolerate each other’s presences as they travel:
- Along a shared foraging path
- Around a known food source
Identifying Male And Female Cockroaches by Species
The differences outlined above mainly pertain to the American cockroach. With other types of roaches, like the German, Oriental, or brown-banded cockroach, the identifiers between males and females can vary.
With German cockroaches, the male is far more slender and a little smaller than the female. Because these roaches are already the smallest of their kind, the size difference won’t be very stark. However, the slim design of their bodies will help tell them apart.
Females will be much broader. They will contain up to 40 eggs before depositing them into an ootheca. That’s among the highest amount for any roach, so they need enough room to store the ample offspring.
For Oriental cockroaches, males have narrowed bodies. Their wings are also more developed and longer than the females’. Despite having wings, neither sex are capable of flight.
In brown-banded cockroaches, males are longer than females due to their wingspan. However, males can fly when they are disturbed and females cannot.
The female has shorter wings and a larger abdomen, which inhibits her ability to fly. The wings on a male will extend the full length of his body, making them a clear identifier.
Male vs. Female Cockroaches
|Male cockroaches||Female cockroaches|
|Smaller in size than female cockroaches||Larger in size than male roaches to hold egg sacs.|
|Slender abdomen with a pointed last segment.||Boat-shaped abdomen with a blunt last segment.|
|Male cockroaches have a longer wingspan than females, allowing all types, except Oriental cockroaches, to fly.||Female cockroaches have shorter wingspan than male cockroaches, and brown-banded female cockroaches cannot fly.|
|Male cockroaches have a cerci with 18-19 segments.||Females have a cerci with 13-14 segments.|
|The seventh segment is not divided.||Divided sternum on the seventh segment|
|Smaller antennae than female cockroaches.||Larger antenna than male cockroaches.|
|Try to get close to the females but are pushed to the edges of the group.||Gather in groups and push the males out.|
Whether it is parts of their bodies, their wings, their reproductive organs, or how they socialize, male and female cockroaches are different. Keep an eye out for these identifiers so that you can find the eggs more easily.