Cockroaches are flat beetle like pest insects that are often associated with human habitation. The pest species are well adapted to live in and around homes and other buildings.
Identify the problem
German Cockroaches, thought to have originated in North East Africa, are by far the most widely distributed disease spreading cockroaches worldwide.These are among the smaller species of cockroach. They are brown in colour with two dark stripes running down the length of the thorax (body segment near the head). German cockroaches are fast breeders having 3-4 generations per year and time from egg to adult in summer is as little as 40 days.
German cockroaches are often found in kitchens and sculleries; in areas that are warm and moist such as behind ovens, fridges, freezers and under sinks. If German cockroaches are found in other areas of a house it usually indicates a large population.
American Cockroaches are up to 4 cm long and has a yellow band around the thorax. American cockroaches mature much more slowly than German roaches taking 6-12 months, however a female may lay as many as 50 egg cases containing as many as 25 eggs each so nymph numbers can rise rapidly in certain conditions. In warm climates of the North Island Americans can live outdoors as well as indoors. They will live in drier conditions of wall cavities and sub-floors but are often found around sewers and drains. If they move from sewers to food or food preparation areas they can spread disease organisms.
Gisborne Cockroaches, (see opposite) are 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 the Gisborne but its stripes are less distinct and it is much smaller the the adult Gisborne. For more information on identifying cockroach species check out the Landcare Research website.
Native Bush Cockroaches are small (up to 15 mm) cockroaches that live in leaf litter and dark damp places in the bush and gardens. They are not usually regarded as pests but will wander indoors on occasions.
To get rid of cockroaches follow these steps:
- Bait > Place NO Cockroaches Nest Killer Gel Bait in areas where cockroaches have been seen.
- Prevent > Spray around likely cockroach hiding places such as behind, ovens, washers, fridges, freezers, cupboards etc. with NO Cockroaches Nest Killer residual spray. Check out the Tips tab for more information on getting rid of and preventing cockroach infestations.
Stop > Knock down adults and immature cockroaches using NO Cockroach Fumigator or NO Fleas Bug Bomb in each affected room. The fumigant penetrates into the nooks and crannies where cockroaches hide. Remove all dead cockroaches after treatment as females may be carrying eggs that could still hatch.
- Monitor > Set NO Cockroach Traps in affected areas. These will give early indication and control of any re-infestation. Because the traps do not contain a toxin and are certified organic, they can safely be used in sensitive areas such as kitchens, larders and other areas where food is handled or stored.
Did You Know
- It has been reported (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 the winter has been a good breeding season for the pest insects in Auckland with moist conditions and cool weather that has driven the cockroaches into buildings where they find food and warmth.
- Roaches prefer warm, moist and sheltered areas close to food and water. They can however, survive in extremes of heat (Bakers ovens), extremes of cold (Deep freezes) withstand over 2000 times more radiation than human beings and still reproduce and adapt.
- Common pest species - German Blatella germanica, American Periplaneta americana and Gisborne Drymaplaneta semivitta (not to be confused with the native Bush Cockroach Celatoblatta spp.)
- Eliminate food and water sources. Clean up at the end of the day. Put all food in sealed containers, fridge or freezers. Remove garbage in sealed bags.
- 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 also provide protection from insecticides. Therefore, it is important that treatment is maintained for at least three months after you stop seeing cockroaches. With persistence and patience you can get rid of cockroaches and keep them away.
- Fill in cracks and crevices that give cockroaches dark moist places to hide during the day.
- For established infestations, particularly of German cockroaches, use baits followed by NO Fleas Bug Bomb and NO Cockroaches Nest Killer which contain permethrin plus an insect growth regulator (IGR) for long term control and breaking the cockroach life cycle.