Although there are many types of cockroach in New Zealand, we can break them down into two main species. The German cockroach which lives inside buildings and typically breeds inside fridge and deepfreeze motors and around hot water cylinders and the various outdoor cockroaches which live in bark gardens and other types of gardens that heat up in the sunlight. These can range from the large American cockroach to the small native cockroach.
Of the two main types the german cockroach is the most common in Auckland and unlike the outdoor cockroach the female carries her egg sack with her until it begines to hatch out. There can be up to 55 eggs in one egg sack and she produces one every 6 weeks. The new born german cockroach malts once a week for 6 weeks until it becomes an adult and then produces its own egg sack. If left untreated german cockroaches can multiply into the hundreds very quickly.
German cockroaches usually come out at night to forage for food and if you are starting to see then during the day it means that their numbers have increased to the point that they cannot find enough food during the night and are having to forage during the day as well. As a rule of thumb for every one you see during the day there are 6 or 7 coming out at night.
Spraying for german cockroaches is not a very effective means of controlling them as they spend the day in areas such as electric motors where you cannot apply a wet spray. AAA Pest control have developed a three part treatment which the german cockroach which is very effective. First a synthetic pyrethyroid powder is puffed into the areas where the german cockroach lives - fridge and deepfreeze motors, around hot water cylinders and behind stoves, etc. This powder not only kills the german cockroach but has a flushing effect as well causing the german cockroach to come running out into the open.
The powder will kill over 90% of german cockroaches in several hours, however there will always be some hiding in areas where the powder is not applied so the second step is to use a German cockroach bait applied with an applicator gun. This leaves small spots of gel bait about the size of a spot on a domino. This is placed inside cupboards, inside hot water cupboards, behind fridges and deepfreeze and also behind microwaves. The cockroaches that survive the powder are attracted to the bait and eat it. The bait passes through the cockroach and is in turn eaten by other cockroaches. This creates a domino effect so that for every cockroach that eats the bait itself, it can kill up to a dozen cockroaches.
Finally, we use cardboard monitoring traps that contain a German cockroach pheromone. This attracts the german cockroach and contains glue on which the german cockroach walks and becomes stuck.
These traps act as a monitoring device. If you are not trapping cockroaches then you know that the infestation has been cleaned up. These traps last about 6 months.
All chemicals used by AAA Pest Control are very safe for children and pets and are fully approved by Health and Safety.
The out door cockroach is treated in much the same way with the addition of a barrier spray sprayed right around the outside of the house as well as around doors and windows to stop them coming into the house. The outdoor cockroach can be more of a problem in winter as unlike the german cockroach the female actually lays her egg sack which incubates for six weeks and the hatches out 10 or 12 nymps. The outdoor cockroach comes inside to lay her egg sack where it is warm and dry.
By far and away the german cockroach can outbreed the outdoor cockroach. The german cockroach carries her egg sack with her until it begins to hatch out and only then does she lay it. A mature german cockroach in her prime can have up to fifty five eggs in her egg sack. When hatched the new cockroaches, called nymphs, malt once a week for six weeks until they become adults and produce their own egg sacks. Even if you can kill the adult german cockroach if you dont dispose of the body the egg sack continues to incubate and will still hatch out live cockroaches.
One flat we went to in the Mangere, Favona area was so badly infested that when we opened the front door there was an avalanche of about twenty cockroaches from the top of the door. In this case we had no option but to use a misting gun to treat the entire flat and the cockroaches were running up the walls, along the ceiling and falling off. It was literally raining cockroaches. There must have been something like one thousand dead and dying german cockroaches on the floor when we left.
The outdoor cockroach is spread right throughout Auckland and especially in the Eastern suburbs from Remuera, St Johns, Mission Bay, Kohimarama right through to Pakuranga and Howick. These East Auckland areas get lots of sun and the outdoor cockroach loves bark gardens which heat up in the sun. These range from the small native cockroach through to the enormous Gisbourne cockroach. These cockroaches hide in window and door cavities waiting for a chance to come inside. The outdoor cockroach lays her egg sack somewhere warm and leaves it there to hatch. After six weeks there are ten or twelve little cockroaches marching around looking for a way back outside. These do not breed nearly as fast as the german cockroach and you usually only see one at a time.
The little native cockroach seems to breed more quickly than the larger types. At one job at a house in Greenlane we flushed about twenty out of the bark garden on the sunny side of the house.