I have a simple question. What’s the best way to kill cockroaches?

Z. B., Boston MA

A rolled-up newspaper? Seriously, the answer to your question isn’t simple. We could discuss the fastest way, or the least toxic way, or the most effective way to kill cockroaches. Let’s assume you are talking about our main structural cockroach pest, the German cockroach. These are the primary control methods used today:

Cockroach Baits

Baiting is the most acceptable way to kill German cockroaches in residences and the method used most widely. Cockroach baits are pesticides but they are low in toxicity to humans and they are applied as gels or pastes in out of the way cracks and crevices or inside small plastic bait stations which makes the risk to people or pets even lower.

Baits are not the fastest way to kill cockroaches, they do not work immediately. Cockroaches must find and eat the bait before they are killed. Baits are user-friendly and with no noxious odors or fumes after application. They can remain in place and working for a long time. Our cockroach control programs are based on baits. See Why is Cockroach Bait the Best Choice?

Insecticide Sprays and Dusts

Standard pesticide sprays or dusts are also used in cockroach control, especially in heavily infested sites where baits alone may not be able to do the job. More important than the insecticide used is the application technique. The insecticide must be placed into the cracks and crevices where cockroaches hide. Most sprays and dusts are fast-acting.

Insect growth regulators can also be used, alone or mixed with a standard pesticide. Insect growth regulators (IGRs) don’t kill roaches outright but instead prevent them from molting into adult roaches that could reproduce. IGRs are a slow but long-term, low toxicity method of control. See How Does an Insect Growth Regulator Work? 

Cockroach Traps

Sticky traps are a nontoxic way to kill roaches but they are almost never used alone as a control tool. Traps are most effective as a monitor to let the exterminator or the resident know that there are (or are not) cockroaches present. A couple of cockroaches on a sticky trap monitor let us know that it’s time to institute additional controls.

Don’t Overlook the Importance of Good Sanitation

There isn’t a single control method mentioned above that is going to work long-term without additional measures such as decluttering, improving sanitation, removing food sources, and reporting problems. Regular inspections, regular followup, and insecticide reapplication are required. There is no one-size-fits-all solution in German cockroach control, and you don’t have to use only one control method. Each account is different and fortunately both residents and professionals have a variety of effective control methods from which to pick and choose.