Of the different common cockroach pest species, there are some that are considered large cockroaches and others that are referred to as small cockroaches. The large cockroach species include the American cockroach, the brown cockroach, and the smoky-brown cockroach, while the group of small cockroach species are considered to include the German cockroach, the Oriental cockroach, and the brown-banded cockroach. Cockroaches are divided into these groupings for the purposes of controlling infestations of the pests. Extermination methods that work to eliminate large cockroaches from a home don’t work on small cockroaches, and vice versa, so the approach one should take toward controlling cockroach pests differ depending on the species and whether it is a large or small cockroach.
Large cockroaches breed both indoors and outside, meaning that to properly control them you must target both areas. It is common for large cockroaches to breed outdoors, only invading your home occasionally rather than establishing an indoor population. Granular baits are the most effective extermination tool to use against large cockroaches, as well as bait stations that are designed for use on large cockroaches specifically. Granular baits are generally meant to be used outside, which makes them very effective as a means of dealing with large cockroaches around the exterior perimeters of the building. Since this is where most infestations of large cockroaches are coming from, this is the most effective method of exterminating them. If they do happen to be inside, experts recommend you use bait stations that are designed to be used on large cockroach species.
Small cockroaches require a completely different extermination method. Since small cockroach species like the German cockroach have evolved so that they live primarily indoors, outside extermination methods like granular baits will not work to eliminate their presence. Insect Growth Regulators (IGRs) and gel baits are ideal for eliminating small cockroaches. While IGRs do not kill adult roaches and are slow acting, they are very effective at controlling indoor infestations of small cockroaches. This is because they disrupt the development of immature roaches, prevent eggs from hatching, and interfere with reproduction, which has a long term effect on the population of cockroaches infesting a home. IGRs slowly eliminate the infestation as the older roaches die and don’t have new ones to replace them and increase their population. Gel baits are particularly effective, but must be used correctly, as they can pose a health threat to children that might decide to taste one. You only want to use drops at each bait site that are no larger than a pea, placing them in areas that are not easily accessible to children and pets, but are accessible to roaches and in spots where they might frequently travel past such as inside kitchen cabinets and behind refrigerators.
What extermination methods have you tried in the past when dealing with cockroaches?