Know your enemy: The Cockroach

Night time is party time for these creepy crawlers! While you’re sleeping they’re on the move, living it up in nice warm areas, particularly where there’s food. If you see one out during the day, there’s a good chance you have quite a large infestation and overcrowding has forced it to move. The best way to beat these champions of survival is to know what makes them tick.

What are cockroaches?

Cockroaches are highly successful insects. They’ve been around for at least 300 million years and fossil evidence suggests they’ve changed very little in that time. In nature they do a great job cleaning up dead plants and animals that are rotting away.

Their flat bodies allow them to hide in tiny cracks where they’re protected from all sides. Cockroaches like to live in groups and when conditions are right their population can quickly grow. A female can lay 12 to 40 eggs at a time, which sometimes take months to hatch.

Some types of cockroach live for a few months while others live for a year. In this time, the female can lay 5 to 30 batches of eggs. We have small bush cockroaches in New Zealand, but the pests that invade our homes are the larger American, German, Asian and Oriental cockroaches.

Are they a threat or just plain scary?

Pest cockroaches can spread disease. Some live in grease traps, sewers and drains while others love rotting rubbish and food waste. They usually carry harmful pathogens on their skin and inside their gut. These can include staphylococcus, E. coli, salmonella, and hepatitis E. They’re also known to pick up and carry bacteria on their legs. By spreading pathogens onto unprotected food and food preparation areas, cockroaches can cause outbreaks of diarrhoea, dysentery, gastroenteritis, typhus and skin diseases.

How do you control cockroaches?

While it obviously helps to clean up spills, remove scraps and keep food in sealed containers, there will always be cockroach food sources beyond your control. This means some form of pesticide is required. Because cockroaches hide in tight places and frequently lay new eggs that can take a while to hatch, occasionally using fly spray is not going to do the trick.

SURFACE SPRAYS: Ecomist has a highly effective surface spray called Insect Sniper that dries and keeps working for weeks. It can be sprayed around areas that cockroaches like – warm dark places, such as under sinks, behind the fridge, under drawers and in bathroom cupboards. Be careful in kitchen areas; avoid getting surface spray on crockery, utensils and surfaces used for preparing food.

SPACE SPRAYS: Ecomist Insect Killer contains natural pyrethrins that are safe to use around humans, but irritate cockroaches into the open and stop them in their tracks. Ecomist automatic dispensers will keep natural pyrethrins circulating in the air (use on high or medium setting to keep it going at night), ensuring that cockroach communities don’t establish in your home.

Information sources: Auckland Regional Public Health Services
J. Gerozisis, P. Handlington, I. Staunton. 2008. Urban Pest Management in Australia. 5th Edition. UNSW Press.