The common species of cockroach in Ireland are the German Cockroach (blatella germanica) and the Oriental Cockroach (blatta orientalis).
They vary in size and in colour in that the German Cockroach is dark brown and measures about 12mm whilst the Oriental Cockroach is a much darker brown (almost black in colour) and approximately twice the size. They are winged insects but do not fly. The German Cockroach, however, are good climbers thus making it easier for them to migrate to adjoining properties.
Again they are nocturnal so if seen during the day, it can be safely assumed that a large population exists.
Cockroach have demonstrated their resilience to insecticides and teams of Laboratory Technicians in some of the largest Companies in the World are continuously introducing new products in an attempt to stave off immunity issues. However, all of these products are for professional use only.
Just like so many other pests, these species of Cockroach are prolific breeders. The German Cockroach can lay up to 200 eggs in their short lifetime as an adult whilst the Oriental Cockroach will produce similar numbers but in a slightly shorter period.
The greatest threat to our way of life from Cockroaches is the fact that they contaminate everything they come in contact with. The cockroach also releases allergens in to the air which are known to trigger asthma and eczema in children.
Cockroaches are great travellers and the German Cockroach shows a preference to warm and humid conditions whilst the Oriental Cockroach are known to be somewhat cold tolerant.