Wednesday, June 30, 2010

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.

There are several species of cockroach that pester us in our homes and workplaces; the German, Gisborne and American are the most common (see Landcare website for identification). Cockroaches are implicated in transmission of disease. They will often move from drains, bins and decaying matter onto food and food preparation surfaces, transferring bacteria and viruses as they go. The particular difficulty in eradicating cockroach infestations is that cockroaches lay eggs and egg cases in cracks, crevices and areas that are hard to reach with insecticides. The eggs can hatch out weeks and months after treatment, when it appears that the cockroaches have been eliminated.

Remove and cover all food so that cockroaches cannot contaminate it. Sweep and wipe up all spilled foods. If you find you have a cockroach infestation you should eliminate them using a combination of methods. Bait, Barrier, Monitor. First use cockroach bait in many small amounts where cockroaches have been seen. Follow baiting with safe long lasting surface insecticide such as NO Cockroaches or NO Bugs Super to treat the cracks and crevices where cockroaches hide during the day. Pay particular attention to skirting, areas underneath cupboards and sinks, and other warm moist dark spaces.”

While adult cockroaches are large, their nymph stages and eggs can be much smaller and they can hide in very narrow gaps. It is vital that treatment with long lasting surface insecticides are maintained for several months after the last cockroach is seen, so that nymphs that hatch from the eggs are controlled before they get a chance to reach maturity and continue the life cycle.

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 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 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.

A man heard that caffiene can be used as an insecticide. So he poured coffee around his cockroach infested kitchen. It didn't kill the cockroaches and he was kept awake all night by them chatting.


  1. Thank you for this article. It is very informative. I'll make sure to try some of this stuff at my own home.

  2. It is really very hard to eliminate cockroach because they can live without food for months. The best way to eliminate them is to know them better.

  3. Hello Cockroach Pest Control,

    Thank you for your comment. You are correct that cockroaches can be difficult to eliminate; not just because they can live without feeding for long periods.

    They can be eliminated with knowledge of cockroach behaviour, an integrated approach to control including, removal of food sources, baits, surface insecticide, fumigators and persistence as described above.

    I hope that the advice I provide to my followers will give them the knowledge and the tools to get rid of cockroaches and to keep them away.

  4. Cockroaches spread unbelievably quickly. We provide a solution to rid them from your home before they start multiplying and it is called The Pest Free.
    Simply plug it into the wall and it emits short bursts of electro motive force at 50Hz, which is safe for all your pets, environment and your family, but it will send pests heading for the door!

  5. Hello Global Solutions,

    Thank you for your comment. There are many such electronic 'repellent' devices both electromagnetic and ultrasonic that claim to control pests of many sorts. These units may have some effect in reducing the risk of infestations, but they have very little effect in removing an infestation that has already established.

    I have been called to many homes, offices, shops and factories where these units have been used without effect.

    Pests such as rodents are neo-phobic and so are wary of changes in their environment. Such devices will tend to make them 'quiet' for a period. But rodents become used to such changes within two weeks. They are not likely to be induced to leave what is their home.



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