The health risks of cockroaches and how to eradicate them

Trick cockroaches into thinking you are feeding them.


The summer rains and warm temperatures make for ideal conditions for cockroaches to thrive as the humid conditions allow them to develop into adulthood faster and there is more food to be found, especially in dense urban areas, Kempton Express reports.

Around this time of year, colonies of cockroaches flourish and reproduce at an alarming rate, so we need to be on the lookout for these pests as they are not only a nuisance but a serious health risk too.

READ MORE: Owner of Raj restaurant speaks out after customer finds cockroach in food

“One female German cockroach will have one egg capsule every one to two months, with 48 eggs in each capsule. An adult will live for up to 180 days (about six months). Now you can just imagine the number of germs that one single cockroach can spread around your home in half a year,” said Bianca Botha, technical sales specialist for Bayer Environmental Science.

At this rate, just one cockroach can produce over 200 nymphs in her short lifespan.

Health risks

Besides being a creepy annoyance, cockroaches pose a whole host of health risks to the community. Few people know that cockroaches are the number one cause for the spread of Tuberculosis via the pathogens that are carried on their bodies.

Humans breathe in the pathogens or come into direct contact with the cockroaches’ excretion and regurgitation. Other pathogens which these insects carry include zoonotic bacteria such as Salmonella spp. and Typhus, and they also spread infectious viruses like Influenza and Hepatitis.

How do you know if you have cockroaches in your home?

As soon as you start noticing their droppings, which typically look like grains of pepper, it is a sign that you do have a cockroach problem. These droppings will usually be found in floor corners, cabinets and drawers.

Food, warmth and moisture are the preferred breeding ground for cockroaches. It is also not uncommon for cockroaches to enter the casings of washing machines and dish washers, says Neel Rust, chief operating officer of Laeveld Agrochem.

Cockroaches are nocturnal and come out looking for food at night, so you might not spot them in your homes much during the day. However, they do leave traces of their presence behind.

Look out for trails of faecal matter in the form of little brown, sticky spots in tight spaces such as around cupboard hinges and beneath your microwave.

In South Africa, we mainly find three types of cockroaches although there are about 4 600 species worldwide. The most commonly found in this country are the German cockroaches.

They are light brown with two dark stripes on their heads, and they inhabit the warm, humid spaces in your kitchen or bathrooms.

The red-colour American type is the biggest in South Africa and can grow to 4cm long. They pose the biggest health threat as they lurk in unhygienic places such as sewers, steam tunnels and your household drains.

Oriental cockroaches spend the bulk of their time outside, unless they find organic material in your home to feed on. You can identify them by their black colour.

How do you get rid of them?

Neel explains further that cockroaches are prevalent year-round. To eliminate cockroaches and prevent re-infestation is obviously every household’s main aim.

It is common knowledge that cockroaches can enter a house through various openings – for example cracks, drain pipes and vents. It is therefore important to understand that control will be best achieved through a combination of actions.

These include using bait, treating areas on the outside of your house which could be a refuge area for cockroaches, as well as treating those cracks, drain pipes and vents, referred to earlier.

“Sanitation is the primary way to get rid of these pesky pests. If you manage a clean kitchen and bathroom, you will make it very difficult for them to find food,” said Botha.

Not only do you need to keep your home clean, but also dry, as without water, few insects can survive. Therefore, it is wise to check for leaking taps and pipes as these are an easy source of water for insects.

“Ensure that you keep your environment clean and dry and you will have won half the battle against the roaches.”

If the cockroaches are persistently still in your home despite your best cleaning efforts, you can use chemical treatments such as gel baits, which you place near where the cockroaches have their harbourage area, but away from your cutlery and food.

Place a 3mm spot outside the nest and lure the adults into eating the bait instead of other food – they will then return to their nymphs and feed the bait to them too.

After the adult cockroach dies, other cockroaches will eat them and they, in turn, will also be poisoned by the gel bait. This is called the cannibalism effect. A good quality bait should last for 12 weeks and can be reapplied if necessary.

“You want to trick the cockroaches into thinking that you are feeding them instead of eradicating them. They are, after all, very clever insects,” said Botha.

Owner of Raj restaurant speaks out after customer finds cockroach in food

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