- There are ways to mitigate small roach invasions, but infestations should be handled by exterminators.
- According to an exterminator, glue strips are a great option when handling small numbers of roaches.
- Close up any openings to a home and maintain a vegetation-free zone to keep roaches out.
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You probably know the feeling – the stomach-dropping moment when you hear a faint scuffle on your floor and look up to see a large, dark roach scuttling across your room or kitchen. No bug infestation is a particularly fun experience, but roaches somehow take things to a whole new level.
According to Scot Hodges, vice president of technical services for Arrow Exterminators, cockroaches fall into two categories: domestic or peridomestic. Peridomestic roaches live in our surroundings but will typically migrate indoors once the weather gets colder. Domestic roaches, on the other hand, tend to coexist with humans in homes all the time.
Because of this difference, Hodges likes to classify the arrival of peridomestic roaches as either an infestation or invasion. An invasion is when roaches have only just sought refuge in a house, like when you open your garage door and see a roach scuttle across the concrete. Invasions are easier to manage by identifying how and why they arrived in the first place, then closing up entry points to a house and eliminating the few that have already entered.
An infestation, however, is when the roaches are living and completing their entire life cycles in a house. “Once they move in, they do not move back out. You either have to kill them, or live with them,” Hodges says.
How to get rid of roaches
Hodges says there’s no singular silver bullet approach that will completely eliminate roaches from a house, but rather a combination of many to help deal with the problem. These methods help mitigate small invasions. An exterminator should be called in the event there’s a larger issue.
Eliminate any reasons and ways for roaches to enter a house
The first line of defense when combating roaches is to “use the pest’s biology to outsmart it,” according to Amy Cross, the project coordinator at the National Pesticide Information Center. In other words: eliminate any causes for why they might be entering the house, such as leaving food out or leaks, and then close up points as many points of entry as possible. This could include affixing a door sweep to cover the crack between the bottom of a door and the ground, or sealing up any holes in the foundation of a house.
This is what Cross calls exclusion, doing this will help to keep roaches out. Hodges also says to maintain clean gutters, and to keep a vegetation-free zone with your landscaping by eliminating any foliage hanging over a house and not adding mulch when it’s not necessary.
Glue strips are one of the safest and most effective solutions for killing roaches, says Hodges. Glue strips are sheets or tubes covered in a sticky substance and they can quickly catch cockroaches within 24 or 48 hours. While Hodges says these won’t work for large infestations, they can help with monitoring the severity of a roach situation and indicate the severity of an issue. If the glue strips catch a bunch of roaches, you have a large infestation and should consider calling in a professional exterminator.
Boric acid is a stomach poison that roaches don’t have any resistance to. A roach must consume the boric acid for it to work. However it does come with a few caveats, as both Cross and Hodges point out. First off, Hodges explains it’s a slow-acting agent and takes a while to actually kill roaches. On top of that, Hodges states people often panic and more than necessary.
“The rule that we use when applying any type of a dust insecticide is that if you can see it, you’ve put out too much,” Hodges says. “If the roach sees that big old pile [of boric acid], they’re just going to walk around.”
Hodges also encourages people to exercise caution, as boric acid can be toxic in large doses according to the National Pesticide Information Center, and to make sure they’re following the instructions on the label when it comes to application.
Diatomaceous earth works as a scratching agent or abrasive meant to get spread out on a surface that insects will then run across. The diatomaceous earth will then damage or stick to the exoskeleton, causing them to dry out. Similar to boric acid, this option is slow working and oftentimes is applied by people in overly large quantities or incorrectly. According to Hodges, using too much can sometimes cause itchy or sore throats with homeowners, and Cross also points out that overapplication can render diatomaceous earth ineffective since the roaches will see it and just crawl around it.
How to identify types of roaches
Hodges says, being able to identify different roach species, as well as if they’re domestic or peridomestic, will help you understand how and why roaches might be entering your house in the first place.
- German cockroaches (Domestic): One of the easier cockroach types to identify according to Hodges, German cockroaches are a tannish color and have two parallel dark stripes, also known as rally stripes, that run from their heads down their backs. And if getting close enough to catch a glimpse isn’t a possibility, Hodges says there’s another way to tell if a home has German cockroaches: the smell, which Hodges likens to a diaper pail. Given German roaches are domestic and already live indoors, Hodges advises focusing on mitigating their presence by eliminating food, water, and harborage in rooms like the bathroom and kitchen.
- Brown-banded cockroaches (Domestic): Similar to German cockroaches, brown-banded roaches also have two light brown stripes. However the stripes on a brown-banded roach go across their abdomen. These roaches like to occupy warm areas of a house, meaning you’ll typically find them in high places.
- Smokybrown roaches (Peridomestic): The bodies of these roaches, which are mostly a deep, dark mahogany with an almost black pronotum, which is the shiny shield-like covering on a roach’s head, can get very large, sometimes 1 ½ to 1 ¾ inches. They can fly very well and typically enter a home via the surrounding vegetation. Because of this, Hodges recommends practicing good exterior maintenance and treatment to help control Smokybrown roaches from migrating indoors.
- American cockroaches (Peridomestic): Like the smokybrown roaches, American cockroaches are large, can move through the air, and tend to get into houses through vegetation. However American cockroaches glide more than fly through the air, and are even bigger than smokybrown roaches, typically growing up to 1 ¾ to 2 inches. Hodges says one of their other more notable features is that their heads look a bit like a raccoon mask, with a mostly gold head and little darker brown spots.
- Oriental cockroaches (Peridomestic): While it’s pretty standard to see cockroaches scuttling across your floor, Oriental cockroaches likely won’t move like that given they’re not very agile. They’re black and don’t have the ability to climb straight up a wall, leading them to mostly infest in ground-level areas like sewage.
While it’s better to leave large roach infestations to the professionals, there are certainly mitigation techniques that can be used to eliminate roaches and keep them from returning to a home. Closing up cracks in a house and getting rid of anything that might be attracting roaches in the first place is the best line of defense, and glue strips are also a highly recommended option when it comes to efficiently catching roaches.