Finding a cockroach in your home is not a pleasant experience, and it can become annoying if they keep on returning. Find out why they enter your home, and how to get rid of this common pest with a few handy tips ….

Types of Cockroaches

There are common pest species in New Zealand – German Blatella germanica, American Periplaneta americana , Black Platyzosteria novaeseelandiae and Gisborne Drymaplaneta semivitta.

German Cockroaches, thought to have originated in North East Africa, are by far the most widely distributed disease spreading cockroaches worldwide. The Gisborne Cockroach  is also commonly associated with people and can be distinguished from the German by its distinct pale stripes down either side. The native Bush cockroach can be mistaken for Gisborne but its stripes are less distinct. For more information on identifying cockroach species check out the Landcare Research website.

Why Do Cockroaches Enter Homes?

Roaches prefer warm, moist and sheltered areas close to food and water. They can however, survive in extremes of heat (even baker’s ovens), extremes of cold (deep freezes) withstand over 2000 times more radiation than human beings and still reproduce and adapt.

It has been reported recently (Campbell Live 18/05/09) that a large proportion of coffee machines in our cafés are infested with cockroaches. Here they find hot moist conditions and nooks and crannies to hide. The NZ Herald have reported (18/08/09) that last winter was a good breeding season for the pest insects in Auckland with moist conditions and cool weather that drove the cockroaches into buildings where they found food and warmth.

How to Get Rid of Cockroaches

Treatment of a cockroach infestation can be difficult because the eggs and egg cases are often laid in difficult to treat cracks and crevices. Egg cases provide protection from insecticides. Therefore, it is important that treatment is maintained for at least one month after you stop seeing cockroaches.

Carry out treatment as follows:

  1. Cockroaches feed on any scraps of food they can find so check for spilled food down the back of ovens, fridges, furniture etc. And make sure food in the larder is kept in sealed containers.
  2. Place cockroach gel bait in areas such as behind fridges and freezers, in rear of cupboards and areas where cockroaches have been seen. Keep it out of the reach of children and pets. The bait will kill feeding cockroaches, those that these individuals regurgitate food for and those that cannibalise them after they die.
  3. Knock down adults and immature cockroaches using cockroach fumigators or bug bombs in each affected room. The fumigant penetrates into the nooks and crannies where cockroaches hide; helping to flush them out and kill them.
  4. Be sure to remove all dead cockroaches after treatment as females may be carrying eggs that could still hatch.
  5. After baits have been in place for at least one week, spray likely cockroach hiding places such as behind, ovens, fridges, freezers, cupboards etc. using residual surface insecticide containing deltamethrin or permethrin (e.g. Kiwicare NO Cockroaches or NO Bugs Super). These give long lasting protection from crawling insects. Any nymphs that hatch from eggs over this period will contact the treated surfaces and be controlled before reaching sexual maturity. Flea control surface sprays such as Kiwicare NO Fleas Total containing insect growth regulators will prevent eggs hatching and nymphs reaching maturity. This is also a good strategy for effective control.
  6. Spray accessible cracks and crevices with a flushing insecticide. Borer injector aerosol is useful as it has a long nozzle that can be used to get insecticide deep into crack and cervices to flush out cockroaches and deny them these harborages.
  7. Cockroach traps are not only an effective way to ‘mop up’ cockroach adults and nymphs without using insecticide the traps also act as early warning indicators of infestation. Keep them in position permanently and check them once a week. If cockroaches get into your home again you will find them in the traps and be able to deal with them as above, BEFORE they are a problem. (Kiwicare’s traps are BioGro certified organic.)

Article Brought To You By Kiwicare  kiwicare

Kiwicare is New Zealand’s own manufacturer and distributor of pest control, garden care and home maintenance products. The Kiwicare website contains advice on the eradication and prevention of all sorts of pests that bother us in New Zealand. Learn how to get rid of rats and mice, flies, spiders, ants, cockroaches, fleas, bed bugs and other creepy crawlies. Protect your plants from aphids, grass grub, caterpillars, weeds and more. Keep biting insects at bay with the Safari range of insect repellents. See the BioGro certified organic range of products to help you stay pest free without chemicals.

How to Get Rid of Cockroaches, 5.0 out of 5 based on 88 ratings



  1. Jason says:

    What a great article, very helpful advice, I like the way it makes clear that cockroaches will not be gone overnight and that it takes some time with the right treatment.

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    Rating: 4.8/5 (5 votes cast)
  2. Cockroach Invasion

    There has been a recent surge in cockroach infestations in the warmer parts of New Zealand. Over the last couple of months, a time when sales normally slacken off as colder weather slows cockroaches down, sales of pest control products specifically designed to control cockroaches have increased to record levels.

    Cockroaches are large resilient beetles often referred to as the creatures that will ‘inherit the Earth’ in the event of a nuclear catastrophe. This may or may not be true, but they can be difficult to eradicate from buildings once they become established.

    It is likely that the warm summer followed by an extended mild and damp autumn has seen numbers swell, particularly in the North Island and top of the South. Now the recent high rainfall is driving cockroaches to seek shelter and warmth in our increasingly well heated homes.

    I also recommended that monitoring for cockroaches is carried out at all times. If your property has had an infestation in the past then it is likely to be susceptible to infestation again. Non-toxic cockroach traps are an excellent way to check for infestations. They can be safely used in sensitive areas like kitchens and pantries. Cockroach traps are simple non-toxic fold out sticky boards supplied with tablets that attract the cockroach adults and nymphs to the trap. The traps can be checked regularly and if cockroaches are found an elimination treatment can be carried out as above before they have time to become established.

    Also, think about how the cockroaches may have found their way inside. In many warmer and humid parts of New Zealand the cockroaches can survive outside, so consider placing a chemical barrier around the house and other buildings. This can be a barrier of insecticide such as those mentioned previously or slow release NO Insects Lawngard Prills sprinkled in ring around the building. For those who prefer not to use insecticide there are organic options such as NO Insects Barrier containing capsaicin, the hot stuff found in chillies, which can be painted on surfaces where cockroaches might otherwise gain entry.

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  3. delightful says:

    It is likely that the warm summer followed by an extended mild and damp autumn has seen numbers swell, particularly in the North Island and top of the South. Now the recent high rainfall is driving cockroaches to seek shelter and warmth in our increasingly well heated homes.

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    Rating: 3.3/5 (3 votes cast)
  4. Hello delightful,

    I couldn’t have said that any better myself.

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    Rating: 5.0/5 (5 votes cast)
  5. The Kiwicare website has a great new look and many new features including interactive problem solvers for home pests and garden pests, diseases and health.
    You may find some of the links in this article try and take you to the page that no longer exists. The error page however will tell you go to the home page and you will easily find the new page on the subject you seek.

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    Rating: 5.0/5 (2 votes cast)
  6. Francine says:

    OMG after reading the info on cockroaches I have to admit to an almost reverent admiration!!! When taking them on its out right warfare hahaha. Not funny too some I guess but I also have them and can only marvel at their survival skills. Heres too evolution! But will take on the advice given as my hubby is almost phobic about them! Will keep you posted as to who is winning! Thanx for the info.

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    Rating: 4.0/5 (3 votes cast)

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