Why Do Cockroaches Exist?

Cockroaches are a domestic nuisance that carry harmful bacteria that they leave behind on our kitchen countertops and food. They are known for their ability to survive in almost any environment and for being able to reproduce quickly.

These insects are one of the most common household pests that fill us with fear, and the lowly cockroach quite rightly has the reputation of being disgusting and filthy. Although this is the case, it doesn’t mean all cockroaches are the same as some play a vital role in the ecosystem.

Are All Cockroaches Pests?

No, not at all. Of more than 5,500 species of roach worldwide, only around 30 of them are considered pests, with a few of these listed as serious household pests that can be bad for our health.

The USA is home to some 70 types of cockroaches, with the majority of these living in forests (sylvatic) and similar areas.

What Is the Purpose of Cockroaches?

Cockroaches have been wandering the Earth for millions of years, and their appearance hasn’t really changed since prehistoric times. They have lived alongside mankind, first in caves and today in and around our homes.

Aside from the pest cockroaches that can plague our lives in our homes and places of work, wild cockroaches play an important role in the environment in many ways, which we will look at below. 

American cockroach outside in leaf litter
American roach outdoors. Image: Whitney Cranshaw, Colorado State University, Bugwood.org

Why Are Cockroaches Good for the Environment?

Roaches Are Decomposers

Cockroaches are omnivores, and they will eat almost anything. They recycle organic matter by eating decaying plant material, fungi, algae, dead animals, and even feces.  

As well as breaking down organic matter, they act as natural composters to produce fertilizer and restore nutrients. Nitrogen is released back into the soil through cockroach poop and is essential to plant growth. 

They can also break down and digest cellulose in wood (as can termites), which forests rely on to decay wood and other plant materials.[1]

Cockroaches Are Used and Eaten by Other Animals

In the wild and in your yard, cockroaches are part of the diets of many birds, mammals, amphibians, and reptiles.

Some parasitic wasps lay their eggs inside cockroaches. The female parasitoid wasp, Ampulex compressa, lays her egg on or inside the roach’s body, eventually killing it. When the larvae hatch inside the roach, it feeds on the cockroach by feasting on its insides as it is a good source of protein.

Another parasitic wasp, Aprostocetus hagenowii, parasitizes the egg cases of larger peridomestic roaches (brownbanded, American, Australian, smokybrown, oriental, and Florida woods roaches). She lays her eggs inside the roach egg, which feeds on the unborn roaches. 

Are Roaches Ever Likely to Become Extinct?

It is unlikely that cockroaches will become extinct as they have been around for millions of years and have managed to adapt so they can survive almost anything.

As much as we’d like to see the pest roaches that invade our homes disappear, we wouldn’t want the wild roaches to suffer the same fate because this would be bad for the forest environment.

Remember, roach droppings contain nitrogen, which gets released into the soil and is used by plants. If cockroaches were wiped out, plants and all forest health would suffer, as would a lot of other creatures that depend on it. 

Are Cockroaches Actually Useful?

Cockroaches in the wild are a necessary part of nature and have an active role within the ecosystem. The pest roaches that invade our homes are certainly not useful. 

A roach infestation is bad for our health in more ways than one. As well as leaving bacteria on surfaces, roaches can trigger asthma attacks and allergy symptoms, and an infestation can be a major cause of anxiety.  

Despite being beneficial to the environment, you still want to avoid an infestation in your home. If you spot any signs of roaches, immediately seek help from a professional pest control company, or do it yourself.

[1] https://encounterswithwildlife.wordpress.com